diff --git a/Application/Helper/Controller.hs b/Application/Helper/Controller.hs
index 3aa7c2a..dd6cfca 100644
--- a/Application/Helper/Controller.hs
+++ b/Application/Helper/Controller.hs
@@ -1,5 +1,71 @@
 module Application.Helper.Controller where
 
 import IHP.ControllerPrelude
+import Generated.Types
+import Data.Time.Clock (addUTCTime)
+import Data.List (sortBy)
 
--- Here you can add functions which are available in all your controllers
\ No newline at end of file
+-- Here you can add functions which are available in all your controllers
+
+-- | Returns the set of widget IDs that are currently in regression.
+--
+-- A regression is defined as: a widget that has an OutcomeSignal(improved)
+-- for any deployment, followed by a new Annotation(severity IN high/critical)
+-- created more than 1 day after the signal's observed_at (grace period).
+regressedWidgetIds :: [OutcomeSignal] -> [Annotation] -> [Id Widget]
+regressedWidgetIds signals annotations =
+    [ wid
+    | wid <- nub (map (.widgetId) signals)
+    , isInRegression signals annotations wid
+    ]
+
+isInRegression :: [OutcomeSignal] -> [Annotation] -> Id Widget -> Bool
+isInRegression signals annotations wid =
+    let improvedSignals = filter (\s -> s.widgetId == wid && s.signalType == "improved") signals
+        highAnns        = filter (\a -> a.widgetId == wid
+                                    && a.severity `elem` ["high", "critical"]
+                                    && isNothing a.retractedAt) annotations
+        graceEnd sig    = addUTCTime (24 * 3600) sig.observedAt
+    in any (\sig -> any (\ann -> ann.createdAt > graceEnd sig) highAnns) improvedSignals
+
+-- | Computes the number of completed improvement cycles per widget.
+--
+-- A cycle is counted when:
+--   1. A RequirementCandidate for the widget was accepted
+--   2. A DecisionRecord exists for that requirement/candidate
+--   3. A DeploymentRecord exists for that decision
+--   4. A new RequirementCandidate was subsequently created for the same widget
+--
+-- Returns a list of (widgetId, cycleCount) for widgets with cycleCount >= 1,
+-- sorted descending by cycleCount.
+widgetCycleCounts
+    :: [RequirementCandidate]
+    -> [Requirement]
+    -> [DecisionRecord]
+    -> [DeploymentRecord]
+    -> [(Id Widget, Int)]
+widgetCycleCounts candidates requirements decisions deployments =
+    sortBy (\(_, a) (_, b) -> compare b a)
+    [ (wid, cycleCount wid)
+    | wid <- nub (map (.sourceWidgetId) candidates)
+    , cycleCount wid >= 1
+    ]
+  where
+    -- A completed cycle: accepted candidate → requirement → decision → deployment
+    completedCycleDeploymentTimes wid =
+        [ dr.deployedAt
+        | c   <- filter (\x -> x.sourceWidgetId == wid && x.status == "accepted") candidates
+        , req <- filter (\x -> x.sourceCandidateId == c.id) requirements
+        , dec <- filter (\x -> x.requirementId == Just req.id) decisions
+        , dr  <- filter (\x -> x.decisionId == dec.id) deployments
+        ]
+
+    cycleCount wid =
+        let deplTimes = completedCycleDeploymentTimes wid
+            -- For each completed cycle, check if a subsequent candidate was created
+            widCandidates = filter (\x -> x.sourceWidgetId == wid) candidates
+        in length
+            [ ()
+            | deplTime <- deplTimes
+            , any (\c -> c.createdAt > deplTime) widCandidates
+            ]
\ No newline at end of file
diff --git a/Application/Migration/1743292800-ihf-phase4-outcome-observation.sql b/Application/Migration/1743292800-ihf-phase4-outcome-observation.sql
new file mode 100644
index 0000000..c87f787
--- /dev/null
+++ b/Application/Migration/1743292800-ihf-phase4-outcome-observation.sql
@@ -0,0 +1,57 @@
+-- IHF Phase 4: Outcome Observation and Antifragility Loop
+-- Adds: deployment_records, outcome_signals (append-only), change_evaluations
+
+CREATE TABLE deployment_records (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    impl_ref_id UUID REFERENCES implementation_change_references(id) ON DELETE SET NULL,
+    decision_id UUID NOT NULL REFERENCES decision_records(id) ON DELETE RESTRICT,
+    version_ref TEXT NOT NULL,
+    deployed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
+    deployed_by UUID REFERENCES users(id),
+    notes TEXT,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
+);
+
+CREATE INDEX deployment_records_decision_id_idx ON deployment_records (decision_id);
+CREATE INDEX deployment_records_deployed_at_idx ON deployment_records (deployed_at DESC);
+
+CREATE TABLE outcome_signals (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    widget_id UUID NOT NULL REFERENCES widgets(id) ON DELETE CASCADE,
+    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
+    signal_type TEXT NOT NULL,
+    value NUMERIC,
+    observed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
+);
+
+CREATE INDEX outcome_signals_widget_id_idx ON outcome_signals (widget_id);
+CREATE INDEX outcome_signals_deployment_id_idx ON outcome_signals (deployment_id);
+CREATE INDEX outcome_signals_observed_at_idx ON outcome_signals (observed_at DESC);
+
+CREATE OR REPLACE FUNCTION prevent_outcome_signal_mutation()
+RETURNS TRIGGER AS $$
+BEGIN
+    RAISE EXCEPTION 'outcome_signals is append-only: UPDATE and DELETE are not permitted';
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER outcome_signals_no_update
+    BEFORE UPDATE ON outcome_signals
+    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();
+
+CREATE TRIGGER outcome_signals_no_delete
+    BEFORE DELETE ON outcome_signals
+    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();
+
+CREATE TABLE change_evaluations (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
+    decision_id UUID REFERENCES decision_records(id) ON DELETE SET NULL,
+    score SMALLINT NOT NULL CHECK (score BETWEEN 1 AND 5),
+    rationale TEXT NOT NULL,
+    evaluated_by UUID REFERENCES users(id),
+    evaluated_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
+    UNIQUE (deployment_id)
+);
+
+CREATE INDEX change_evaluations_deployment_id_idx ON change_evaluations (deployment_id);
diff --git a/Application/Schema.sql b/Application/Schema.sql
index 6ee82ad..eb5f286 100644
--- a/Application/Schema.sql
+++ b/Application/Schema.sql
@@ -205,3 +205,61 @@ CREATE INDEX impl_change_refs_decision_id_idx ON implementation_change_reference
 
 -- Back-reference: which candidate was promoted to a requirement (Phase 3)
 ALTER TABLE requirement_candidates ADD COLUMN requirement_id UUID REFERENCES requirements(id) ON DELETE SET NULL;
+
+-- Deployment records — connect decisions to deployed versions (Phase 4)
+CREATE TABLE deployment_records (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    impl_ref_id UUID REFERENCES implementation_change_references(id) ON DELETE SET NULL,
+    decision_id UUID NOT NULL REFERENCES decision_records(id) ON DELETE RESTRICT,
+    version_ref TEXT NOT NULL,
+    deployed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
+    deployed_by UUID REFERENCES users(id),
+    notes TEXT,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
+);
+
+CREATE INDEX deployment_records_decision_id_idx ON deployment_records (decision_id);
+CREATE INDEX deployment_records_deployed_at_idx ON deployment_records (deployed_at DESC);
+
+-- Outcome signals — append-only observation of widget behaviour post-deployment (Phase 4)
+CREATE TABLE outcome_signals (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    widget_id UUID NOT NULL REFERENCES widgets(id) ON DELETE CASCADE,
+    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
+    signal_type TEXT NOT NULL,
+    value NUMERIC,
+    observed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
+);
+
+CREATE INDEX outcome_signals_widget_id_idx ON outcome_signals (widget_id);
+CREATE INDEX outcome_signals_deployment_id_idx ON outcome_signals (deployment_id);
+CREATE INDEX outcome_signals_observed_at_idx ON outcome_signals (observed_at DESC);
+
+CREATE OR REPLACE FUNCTION prevent_outcome_signal_mutation()
+RETURNS TRIGGER AS $$
+BEGIN
+    RAISE EXCEPTION 'outcome_signals is append-only: UPDATE and DELETE are not permitted';
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER outcome_signals_no_update
+    BEFORE UPDATE ON outcome_signals
+    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();
+
+CREATE TRIGGER outcome_signals_no_delete
+    BEFORE DELETE ON outcome_signals
+    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();
+
+-- Change evaluations — one score per deployment (Phase 4)
+CREATE TABLE change_evaluations (
+    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
+    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
+    decision_id UUID REFERENCES decision_records(id) ON DELETE SET NULL,
+    score SMALLINT NOT NULL CHECK (score BETWEEN 1 AND 5),
+    rationale TEXT NOT NULL,
+    evaluated_by UUID REFERENCES users(id),
+    evaluated_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
+    UNIQUE (deployment_id)
+);
+
+CREATE INDEX change_evaluations_deployment_id_idx ON change_evaluations (deployment_id);
diff --git a/SCOPE.md b/SCOPE.md
index de73719..d4b6d9a 100644
--- a/SCOPE.md
+++ b/SCOPE.md
@@ -65,9 +65,9 @@ IHF treats every meaningful UI element as a **governed interaction artifact** ra
 
 ## Current State
 
-- Status: Phase 3 complete — governance and decision linkage implemented
-- Implementation: Phase 0 complete (specification); Phase 1 complete (widget registry, event capture, annotations, hub dashboard, auth); Phase 2 complete (annotation severity, annotation threads, requirement candidates, triage lifecycle, reviewer assignment, triage dashboard); Phase 3 complete (requirement promotion, decision records, policy references, implementation change references, governance audit trail dashboard)
-- Stability: core artifact model and schema are stable; Phase 3 data model (Requirement, DecisionRecord, PolicyReference, ImplementationChangeReference) is additive and stable
+- Status: Phase 4 complete — outcome observation and antifragility loop implemented
+- Implementation: Phase 0 complete (specification); Phase 1 complete (widget registry, event capture, annotations, hub dashboard, auth); Phase 2 complete (annotation severity, annotation threads, requirement candidates, triage lifecycle, reviewer assignment, triage dashboard); Phase 3 complete (requirement promotion, decision records, policy references, implementation change references, governance dashboard); Phase 4 complete (deployment records, outcome signals, pre/post comparison, regression detection, change evaluation, recurrence tracking, antifragility dashboard)
+- Stability: core artifact model and schema are stable; Phase 4 data model (DeploymentRecord, OutcomeSignal, ChangeEvaluation) is additive and stable; outcome signals and interaction events are append-only (DB triggers)
 - Usage: reference implementation running on IHP v1.5 + PostgreSQL; `devenv up` to start
 
 ---
diff --git a/Test/Integration.hs b/Test/Integration.hs
index 5d6e3c5..b21b81c 100644
--- a/Test/Integration.hs
+++ b/Test/Integration.hs
@@ -7,6 +7,10 @@ import IHP.Log.Types
 import IHP.ControllerPrelude hiding (query)
 import System.Environment (lookupEnv)
 import Generated.Types
+import Data.Time.Clock (addUTCTime, getCurrentTime)
+import Application.Helper.Controller (regressedWidgetIds, widgetCycleCounts)
+import Control.Exception (try, SomeException)
+import Data.Either (isLeft)
 
 -- Integration tests run with a temporary PostgreSQL database.
 -- Run: nix flake check  (or `test` inside devenv)
@@ -657,3 +661,284 @@ main = do
                     let accepted = filter (\d -> d.outcome == "accepted") decisions
                     length accepted `shouldBe` 1
                     deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: DeploymentRecord create + link to decision
+            -- ----------------------------------------------------------------
+            describe "DeploymentRecord" do
+                it "creates a deployment linked to a decision" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-dr-hub" |> set #name "P4 DR" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "DR Widget" |> set #widgetType "form"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "DR candidate" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    dr <- newRecord @DecisionRecord
+                        |> set #title "DR decision" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #candidateId (Just candidate.id)
+                        |> createRecord
+                    deployment <- newRecord @DeploymentRecord
+                        |> set #decisionId dr.id
+                        |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    deployment.versionRef `shouldBe` "v1.0.0"
+                    deployment.decisionId `shouldBe` dr.id
+                    fetched <- fetch deployment.id
+                    fetched.versionRef `shouldBe` "v1.0.0"
+                    deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: OutcomeSignal append-only (DB trigger)
+            -- ----------------------------------------------------------------
+            describe "OutcomeSignal append-only" do
+                it "inserts signal successfully" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-sig-hub" |> set #name "P4 Sig" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "Sig Widget" |> set #widgetType "form"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "Sig candidate" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    decision <- newRecord @DecisionRecord
+                        |> set #title "Sig decision" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #candidateId (Just candidate.id)
+                        |> createRecord
+                    deployment <- newRecord @DeploymentRecord
+                        |> set #decisionId decision.id |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    sig <- newRecord @OutcomeSignal
+                        |> set #deploymentId deployment.id
+                        |> set #widgetId     widget.id
+                        |> set #signalType   "improved"
+                        |> createRecord
+                    sig.signalType `shouldBe` "improved"
+                    -- DB trigger prevents UPDATE — exception is caught, connection continues
+                    result <- try (updateRecord (sig |> set #signalType "regressed") :: IO OutcomeSignal)
+                                  :: IO (Either SomeException OutcomeSignal)
+                    isLeft result `shouldBe` True
+                    deleteRecord hub
+
+                it "DB trigger prevents DELETE on outcome_signals" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-sigdel-hub" |> set #name "P4 SigDel" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "SigDel Widget" |> set #widgetType "form"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "SigDel cand" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    decision <- newRecord @DecisionRecord
+                        |> set #title "SigDel dec" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #candidateId (Just candidate.id)
+                        |> createRecord
+                    deployment <- newRecord @DeploymentRecord
+                        |> set #decisionId decision.id |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    sig <- newRecord @OutcomeSignal
+                        |> set #deploymentId deployment.id
+                        |> set #widgetId     widget.id
+                        |> set #signalType   "neutral"
+                        |> createRecord
+                    result <- try (deleteRecord sig) :: IO (Either SomeException ())
+                    isLeft result `shouldBe` True
+                    deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: Regression detection
+            -- ----------------------------------------------------------------
+            describe "Regression detection" do
+                it "detects widget in regression (improved signal then high annotation)" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-reg-hub" |> set #name "P4 Reg" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "Reg Widget" |> set #widgetType "form"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "Reg cand" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    decision <- newRecord @DecisionRecord
+                        |> set #title "Reg dec" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #candidateId (Just candidate.id)
+                        |> createRecord
+                    deployment <- newRecord @DeploymentRecord
+                        |> set #decisionId decision.id |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    -- Record an improved signal with observedAt 10 days ago
+                    now <- getCurrentTime
+                    let tenDaysAgo = addUTCTime (negate $ 10 * 24 * 3600) now
+                    sig <- newRecord @OutcomeSignal
+                        |> set #deploymentId deployment.id
+                        |> set #widgetId     widget.id
+                        |> set #signalType   "improved"
+                        |> set #observedAt   tenDaysAgo
+                        |> createRecord
+                    -- Annotation created now — which is 10 days after signal (> 1 day grace)
+                    ann <- newRecord @Annotation
+                        |> set #widgetId  widget.id
+                        |> set #body      "High severity friction recurred"
+                        |> set #category  "friction"
+                        |> set #severity  "high"
+                        |> set #actorType "user"
+                        |> createRecord
+                    -- Run regression detection
+                    allSignals <- query @OutcomeSignal |> filterWhere (#widgetId, widget.id) |> fetch
+                    allAnns    <- query @Annotation    |> filterWhere (#widgetId, widget.id) |> fetch
+                    let regressed = regressedWidgetIds allSignals allAnns
+                    regressed `shouldContain` [widget.id]
+                    deleteRecord hub
+
+                it "does not flag widget without improved signal" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-noreg-hub" |> set #name "P4 NoReg" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "NoReg Widget" |> set #widgetType "form"
+                        |> createRecord
+                    ann <- newRecord @Annotation
+                        |> set #widgetId widget.id |> set #body "high ann"
+                        |> set #category "friction" |> set #severity "high"
+                        |> set #actorType "user" |> createRecord
+                    let regressed = regressedWidgetIds [] [ann]
+                    regressed `shouldBe` []
+                    deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: ChangeEvaluation create + idempotent
+            -- ----------------------------------------------------------------
+            describe "ChangeEvaluation" do
+                it "creates one evaluation per deployment and rejects duplicates" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-eval-hub" |> set #name "P4 Eval" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "Eval Widget" |> set #widgetType "form"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "Eval cand" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    decision <- newRecord @DecisionRecord
+                        |> set #title "Eval dec" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #candidateId (Just candidate.id)
+                        |> createRecord
+                    deployment <- newRecord @DeploymentRecord
+                        |> set #decisionId decision.id |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    eval1 <- newRecord @ChangeEvaluation
+                        |> set #deploymentId deployment.id
+                        |> set #score        4
+                        |> set #rationale    "Good improvement"
+                        |> createRecord
+                    eval1.score `shouldBe` 4
+                    -- Second evaluation for same deployment → UNIQUE constraint violation
+                    result <- try (newRecord @ChangeEvaluation
+                            |> set #deploymentId deployment.id
+                            |> set #score        3
+                            |> set #rationale    "Duplicate"
+                            |> createRecord :: IO ChangeEvaluation)
+                            :: IO (Either SomeException ChangeEvaluation)
+                    isLeft result `shouldBe` True
+                    deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: Recurrence tracking
+            -- ----------------------------------------------------------------
+            describe "Recurrence tracking" do
+                it "counts cycles for a widget with 2 completed cycles" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-rec-hub" |> set #name "P4 Rec" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "Rec Widget" |> set #widgetType "form"
+                        |> createRecord
+                    -- Cycle 1: candidate → req → decision → deployment
+                    c1 <- newRecord @RequirementCandidate
+                        |> set #title "Rec cand 1" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    req1 <- newRecord @Requirement
+                        |> set #title c1.title |> set #description "d"
+                        |> set #sourceCandidateId c1.id |> set #status "active"
+                        |> createRecord
+                    dec1 <- newRecord @DecisionRecord
+                        |> set #title "Rec dec 1" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #requirementId (Just req1.id)
+                        |> createRecord
+                    now <- getCurrentTime
+                    let pastTime   = addUTCTime (negate $ 2 * 24 * 3600) now
+                        futureTime = addUTCTime (24 * 3600) now
+                    dep1 <- newRecord @DeploymentRecord
+                        |> set #decisionId dec1.id |> set #versionRef "v1.0"
+                        |> set #deployedAt pastTime
+                        |> createRecord
+                    -- Cycle 2: new candidate after dep1 deployment (created in the future relative to dep1)
+                    c2 <- newRecord @RequirementCandidate
+                        |> set #title "Rec cand 2" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted"
+                        |> set #createdAt futureTime
+                        |> createRecord
+                    -- Compute cycle count
+                    allCandidates   <- query @RequirementCandidate |> filterWhere (#sourceWidgetId, widget.id) |> fetch
+                    allRequirements <- query @Requirement |> fetch
+                    allDecisions    <- query @DecisionRecord |> fetch
+                    allDeployments  <- query @DeploymentRecord |> fetch
+                    let cycles = widgetCycleCounts allCandidates allRequirements allDecisions allDeployments
+                    let mCount = lookup widget.id cycles
+                    mCount `shouldBe` Just 1
+                    deleteRecord hub
+
+            -- ----------------------------------------------------------------
+            -- Phase 4: Antifragility dashboard data fetch
+            -- ----------------------------------------------------------------
+            describe "Antifragility dashboard data fetch" do
+                it "returns correct deployment and signal counts" do
+                    hub <- newRecord @Hub
+                        |> set #slug "p4-afd-hub" |> set #name "P4 AFD" |> set #domain "d"
+                        |> createRecord
+                    widget <- newRecord @Widget
+                        |> set #hubId hub.id |> set #name "AFD Widget" |> set #widgetType "panel"
+                        |> createRecord
+                    candidate <- newRecord @RequirementCandidate
+                        |> set #title "AFD cand" |> set #description "d"
+                        |> set #sourceWidgetId widget.id |> set #category "friction"
+                        |> set #status "accepted" |> createRecord
+                    req <- newRecord @Requirement
+                        |> set #title candidate.title |> set #description "d"
+                        |> set #sourceCandidateId candidate.id |> set #status "active"
+                        |> createRecord
+                    decision <- newRecord @DecisionRecord
+                        |> set #title "AFD decision" |> set #rationale "r"
+                        |> set #outcome "accepted" |> set #requirementId (Just req.id)
+                        |> createRecord
+                    dep <- newRecord @DeploymentRecord
+                        |> set #decisionId decision.id |> set #versionRef "v1.0.0"
+                        |> createRecord
+                    _s1 <- newRecord @OutcomeSignal
+                        |> set #deploymentId dep.id |> set #widgetId widget.id
+                        |> set #signalType "improved" |> createRecord
+                    _s2 <- newRecord @OutcomeSignal
+                        |> set #deploymentId dep.id |> set #widgetId widget.id
+                        |> set #signalType "neutral" |> createRecord
+                    -- Verify query path used by antifragility dashboard
+                    let widgetIds = [widget.id]
+                    deployments <- query @DeploymentRecord
+                        |> filterWhereIn (#decisionId, [decision.id]) |> fetch
+                    signals <- query @OutcomeSignal
+                        |> filterWhereIn (#widgetId, widgetIds) |> fetch
+                    length deployments `shouldBe` 1
+                    length signals `shouldBe` 2
+                    let improvedCount = length (filter (\s -> s.signalType == "improved") signals)
+                    improvedCount `shouldBe` 1
+                    deleteRecord hub
diff --git a/Web/Controller/DecisionRecords.hs b/Web/Controller/DecisionRecords.hs
index ded4851..911ea11 100644
--- a/Web/Controller/DecisionRecords.hs
+++ b/Web/Controller/DecisionRecords.hs
@@ -34,26 +34,36 @@ instance Controller DecisionRecordsController where
         render IndexView { records, requirements, users, mOutcomeFilter }
 
     action ShowDecisionRecordAction { decisionRecordId } = do
-        record         <- fetch decisionRecordId
-        policyRefs     <- query @PolicyReference
+        record            <- fetch decisionRecordId
+        policyRefs        <- query @PolicyReference
             |> filterWhere (#decisionId, decisionRecordId)
             |> orderByAsc #createdAt
             |> fetch
-        implRefs       <- query @ImplementationChangeReference
+        implRefs          <- query @ImplementationChangeReference
             |> filterWhere (#decisionId, decisionRecordId)
             |> orderByAsc #linkedAt
             |> fetch
-        mRequirement   <- case record.requirementId of
+        deploymentRecords <- query @DeploymentRecord
+            |> filterWhere (#decisionId, decisionRecordId)
+            |> orderByDesc #deployedAt
+            |> fetch
+        let deploymentIds = map (.id) deploymentRecords
+        evaluations       <- query @ChangeEvaluation
+            |> filterWhereIn (#deploymentId, deploymentIds)
+            |> fetch
+        mRequirement      <- case record.requirementId of
             Nothing  -> pure Nothing
             Just rid -> fetchOneOrNothing rid
-        mCandidate     <- case record.candidateId of
+        mCandidate        <- case record.candidateId of
             Nothing  -> pure Nothing
             Just cid -> fetchOneOrNothing cid
-        users          <- query @User |> fetch
+        users             <- query @User |> fetch
         render ShowView
             { record
             , policyRefs
             , implRefs
+            , deploymentRecords
+            , evaluations
             , mRequirement
             , mCandidate
             , users
diff --git a/Web/Controller/DeploymentRecords.hs b/Web/Controller/DeploymentRecords.hs
new file mode 100644
index 0000000..5849d89
--- /dev/null
+++ b/Web/Controller/DeploymentRecords.hs
@@ -0,0 +1,180 @@
+module Web.Controller.DeploymentRecords where
+
+import Web.Types
+import Web.View.DeploymentRecords.Index
+import Web.View.DeploymentRecords.Show
+import Web.View.DeploymentRecords.New
+import Generated.Types
+import IHP.Prelude
+import IHP.ControllerPrelude
+import Data.Time.Clock (addUTCTime, NominalDiffTime)
+import Text.Read (readMaybe)
+import Data.String.Conversions (cs)
+
+instance Controller DeploymentRecordsController where
+    beforeAction = ensureIsUser
+
+    action DeploymentRecordsAction = do
+        records     <- query @DeploymentRecord |> orderByDesc #deployedAt |> fetch
+        decisions   <- query @DecisionRecord |> fetch
+        signals     <- query @OutcomeSignal |> fetch
+        evaluations <- query @ChangeEvaluation |> fetch
+        render IndexView { records, decisions, signals, evaluations }
+
+    action ShowDeploymentRecordAction { deploymentRecordId } = do
+        record      <- fetch deploymentRecordId
+        decision    <- fetch record.decisionId
+        mImplRef    <- case record.implRefId of
+            Nothing  -> pure Nothing
+            Just rid -> fetchOneOrNothing rid
+        mRequirement <- case decision.requirementId of
+            Nothing  -> pure Nothing
+            Just rid -> fetchOneOrNothing rid
+        mCandidate  <- case decision.candidateId of
+            Nothing  -> pure Nothing
+            Just cid -> fetchOneOrNothing cid
+        mWidget     <- case mCandidate of
+            Nothing -> pure Nothing
+            Just c  -> fetchOneOrNothing c.sourceWidgetId
+        signals     <- query @OutcomeSignal
+            |> filterWhere (#deploymentId, deploymentRecordId)
+            |> orderByDesc #observedAt
+            |> fetch
+        mEvaluation <- query @ChangeEvaluation
+            |> filterWhere (#deploymentId, deploymentRecordId)
+            |> fetchOneOrNothing
+        users       <- query @User |> fetch
+        comparison  <- computeComparison record.deployedAt mWidget
+        render ShowView
+            { record
+            , decision
+            , mImplRef
+            , mRequirement
+            , mCandidate
+            , mWidget
+            , signals
+            , mEvaluation
+            , users
+            , comparison
+            }
+
+    action NewDeploymentRecordAction = do
+        decisions <- query @DecisionRecord |> fetch
+        implRefs  <- query @ImplementationChangeReference |> fetch
+        users     <- query @User |> fetch
+        mDecisionId <- paramOrNothing @(Id DecisionRecord) "decisionId"
+        let record = newRecord @DeploymentRecord
+        render NewView { record, decisions, implRefs, users, mDecisionId }
+
+    action CreateDeploymentRecordAction = do
+        decisions <- query @DecisionRecord |> fetch
+        implRefs  <- query @ImplementationChangeReference |> fetch
+        users     <- query @User |> fetch
+        mUser     <- currentUserOrNothing
+        let deployedBy = fmap (.id) mUser
+
+        let record = newRecord @DeploymentRecord
+        record
+            |> fill @'["decisionId", "implRefId", "versionRef", "notes"]
+            |> set #deployedBy (fmap (Id . unId) deployedBy)
+            |> validateField #versionRef nonEmpty
+            |> ifValid \case
+                Left  r -> render NewView { record = r, decisions, implRefs, users, mDecisionId = Just r.decisionId }
+                Right r -> do
+                    created <- createRecord r
+                    setSuccessMessage "Deployment record created"
+                    redirectTo ShowDeploymentRecordAction { deploymentRecordId = created.id }
+
+    action RecordOutcomeSignalAction { deploymentRecordId } = do
+        signalType <- param @Text "signalType"
+        mValue     <- paramOrNothing @Double "value"
+        mUser      <- currentUserOrNothing
+        let validTypes = ["improved", "regressed", "neutral", "inconclusive"] :: [Text]
+        unless (signalType `elem` validTypes) do
+            setErrorMessage ("Invalid signal type: " <> signalType)
+            redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+        -- Fetch the deployment to get the widget_id from its decision → candidate chain
+        deployment <- fetch deploymentRecordId
+        decision   <- fetch deployment.decisionId
+        mCandidate <- case decision.candidateId of
+            Nothing  -> pure Nothing
+            Just cid -> fetchOneOrNothing cid
+        case mCandidate of
+            Nothing -> do
+                setErrorMessage "Cannot record signal: no widget linked to this deployment's decision"
+                redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+            Just candidate -> do
+                newRecord @OutcomeSignal
+                    |> set #deploymentId deploymentRecordId
+                    |> set #widgetId     candidate.sourceWidgetId
+                    |> set #signalType   signalType
+                    |> set #value        mValue
+                    |> createRecord
+                setSuccessMessage ("Outcome signal recorded: " <> signalType)
+                redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+
+    action EvaluateChangeAction { deploymentRecordId } = do
+        -- Idempotent: if already evaluated, redirect with message
+        existing <- query @ChangeEvaluation
+            |> filterWhere (#deploymentId, deploymentRecordId)
+            |> fetchOneOrNothing
+        case existing of
+            Just _ -> do
+                setErrorMessage "Already evaluated — one evaluation per deployment."
+                redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+            Nothing -> do
+                mUser <- currentUserOrNothing
+                let evaluatedBy = fmap (.id) mUser
+                scoreText <- param @Text "score"
+                rationale <- param @Text "rationale"
+                let mScore = readMaybe (cs scoreText) :: Maybe Int
+                case mScore of
+                    Nothing -> do
+                        setErrorMessage "Score must be a number between 1 and 5"
+                        redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+                    Just s | s < 1 || s > 5 -> do
+                        setErrorMessage "Score must be between 1 and 5"
+                        redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+                    Just s -> do
+                        when (rationale == "") do
+                            setErrorMessage "Rationale cannot be empty"
+                            redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+                        deployment <- fetch deploymentRecordId
+                        newRecord @ChangeEvaluation
+                            |> set #deploymentId  deploymentRecordId
+                            |> set #decisionId    (Just deployment.decisionId)
+                            |> set #score         (fromIntegral s)
+                            |> set #rationale     rationale
+                            |> set #evaluatedBy   (fmap (Id . unId) evaluatedBy)
+                            |> createRecord
+                        setSuccessMessage "Change evaluated"
+                        redirectTo ShowDeploymentRecordAction { deploymentRecordId }
+
+thirtyDays :: NominalDiffTime
+thirtyDays = 30 * 24 * 3600
+
+computeComparison :: (?modelContext :: ModelContext) => UTCTime -> Maybe Widget -> IO (Maybe (PeriodMetrics, PeriodMetrics))
+computeComparison _ Nothing = pure Nothing
+computeComparison deployedAt (Just w) = do
+    let beforeStart = addUTCTime (negate thirtyDays) deployedAt
+        afterEnd    = addUTCTime thirtyDays deployedAt
+    allEvents      <- query @InteractionEvent |> filterWhere (#widgetId, w.id) |> fetch
+    allAnnotations <- query @Annotation       |> filterWhere (#widgetId, w.id) |> fetch
+    let inWindow s e t = t >= s && t < e
+        evBefore  = filter (\x -> inWindow beforeStart deployedAt x.occurredAt) allEvents
+        evAfter   = filter (\x -> inWindow deployedAt afterEnd x.occurredAt)   allEvents
+        annBefore = filter (\x -> inWindow beforeStart deployedAt x.createdAt && isNothing x.retractedAt) allAnnotations
+        annAfter  = filter (\x -> inWindow deployedAt afterEnd x.createdAt && isNothing x.retractedAt)  allAnnotations
+    pure $ Just (buildMetrics evBefore annBefore, buildMetrics evAfter annAfter)
+
+buildMetrics :: [InteractionEvent] -> [Annotation] -> PeriodMetrics
+buildMetrics events anns = PeriodMetrics
+    { eventCount      = length events
+    , annotationCount = length anns
+    , lowCount        = count "low"
+    , mediumCount     = count "medium"
+    , highCount       = count "high"
+    , criticalCount   = count "critical"
+    }
+  where
+    count sev = length (filter (\a -> a.severity == sev) anns)
diff --git a/Web/Controller/Hubs.hs b/Web/Controller/Hubs.hs
index eacbf71..15ad0ba 100644
--- a/Web/Controller/Hubs.hs
+++ b/Web/Controller/Hubs.hs
@@ -7,9 +7,11 @@ import Web.View.Hubs.New
 import Web.View.Hubs.Edit
 import Web.View.Hubs.TriageDashboard
 import Web.View.Hubs.GovernanceDashboard
+import Web.View.Hubs.AntifragilityDashboard
 import Generated.Types
 import IHP.Prelude
 import IHP.ControllerPrelude
+import Application.Helper.Controller (regressedWidgetIds, widgetCycleCounts)
 
 instance Controller HubsController where
     beforeAction = ensureIsUser
@@ -147,6 +149,13 @@ instance Controller HubsController where
             |> filterWhereIn (#widgetId, widgetIds)
             |> fetch
 
+        -- Outcome signals for regression detection
+        allSignals <- query @OutcomeSignal
+            |> filterWhereIn (#widgetId, widgetIds)
+            |> fetch
+
+        let regressionWidgetIds = regressedWidgetIds allSignals allAnnotations
+
         render GovernanceDashboardView
             { hub
             , widgets
@@ -155,4 +164,58 @@ instance Controller HubsController where
             , recentDecisions
             , allDecisions
             , allAnnotations
+            , regressionWidgetIds
+            }
+
+    action AntifragilityDashboardAction { hubId } = autoRefresh do
+        hub     <- fetch hubId
+        widgets <- query @Widget
+            |> filterWhere (#hubId, hubId)
+            |> fetch
+        let widgetIds = map (.id) widgets
+
+        -- Deployments for this hub's decisions
+        allCandidates <- query @RequirementCandidate
+            |> filterWhereIn (#sourceWidgetId, widgetIds)
+            |> fetch
+        let acceptedCandidateIds = map (.id) (filter (\c -> c.status == "accepted") allCandidates)
+        allRequirements <- query @Requirement
+            |> filterWhereIn (#sourceCandidateId, acceptedCandidateIds)
+            |> fetch
+        let requirementIds = map (.id) allRequirements
+        allDecisions <- query @DecisionRecord
+            |> filterWhereIn (#requirementId, map Just requirementIds)
+            |> fetch
+        let decisionIds = map (.id) allDecisions
+        allDeployments <- query @DeploymentRecord
+            |> filterWhereIn (#decisionId, decisionIds)
+            |> orderByDesc #deployedAt
+            |> fetch
+        let deploymentIds = map (.id) allDeployments
+        allSignals <- query @OutcomeSignal
+            |> filterWhereIn (#widgetId, widgetIds)
+            |> fetch
+        allEvaluations <- query @ChangeEvaluation
+            |> filterWhereIn (#deploymentId, deploymentIds)
+            |> fetch
+        allImplRefs <- query @ImplementationChangeReference
+            |> filterWhereIn (#decisionId, decisionIds)
+            |> fetch
+        allAnnotations <- query @Annotation
+            |> filterWhereIn (#widgetId, widgetIds)
+            |> fetch
+
+        let regressionWidgetIds     = regressedWidgetIds allSignals allAnnotations
+            recurrenceLeaderboard   = take 10 (widgetCycleCounts allCandidates allRequirements allDecisions allDeployments)
+
+        render AntifragilityDashboardView
+            { hub
+            , widgets
+            , allDeployments
+            , allDecisions
+            , allSignals
+            , allEvaluations
+            , allImplRefs
+            , regressionWidgetIds
+            , recurrenceLeaderboard
             }
diff --git a/Web/Controller/Widgets.hs b/Web/Controller/Widgets.hs
index d63aa08..6eafa54 100644
--- a/Web/Controller/Widgets.hs
+++ b/Web/Controller/Widgets.hs
@@ -9,6 +9,7 @@ import Generated.Types
 import IHP.Prelude
 import IHP.ControllerPrelude
 import Data.Aeson (toJSON, object, (.=))
+import Application.Helper.Controller (isInRegression, widgetCycleCounts)
 
 instance Controller WidgetsController where
     beforeAction = ensureIsUser
@@ -39,7 +40,23 @@ instance Controller WidgetsController where
             |> filterWhere (#widgetId, widgetId)
             |> orderByAsc #createdAt
             |> fetch
-        render ShowView { widget, hub, versions, events, annotations }
+        recentSignals <- query @OutcomeSignal
+            |> filterWhere (#widgetId, widgetId)
+            |> orderByDesc #observedAt
+            |> limit 10
+            |> fetch
+        allSignals <- query @OutcomeSignal
+            |> filterWhere (#widgetId, widgetId)
+            |> fetch
+        let isRegressed = isInRegression allSignals annotations widgetId
+        -- Recurrence cycle count for this widget
+        allCandidates  <- query @RequirementCandidate |> filterWhere (#sourceWidgetId, widgetId) |> fetch
+        allRequirements <- query @Requirement |> fetch
+        allDecisions   <- query @DecisionRecord |> fetch
+        allDeployments <- query @DeploymentRecord |> fetch
+        let cycleCounts = widgetCycleCounts allCandidates allRequirements allDecisions allDeployments
+            cycleCount  = fromMaybe 0 (lookup widgetId cycleCounts)
+        render ShowView { widget, hub, versions, events, annotations, recentSignals, isRegressed, cycleCount }
 
     action CreateWidgetAction = do
         let widget = newRecord @Widget
diff --git a/Web/FrontController.hs b/Web/FrontController.hs
index b074cc5..3cb1709 100644
--- a/Web/FrontController.hs
+++ b/Web/FrontController.hs
@@ -15,6 +15,7 @@ import Web.Controller.AnnotationThreads ()
 import Web.Controller.RequirementCandidates ()
 import Web.Controller.Requirements ()
 import Web.Controller.DecisionRecords ()
+import Web.Controller.DeploymentRecords ()
 import Web.Controller.Sessions ()
 
 instance FrontController WebApplication where
@@ -28,6 +29,7 @@ instance FrontController WebApplication where
         , parseRoute @RequirementCandidatesController
         , parseRoute @RequirementsController
         , parseRoute @DecisionRecordsController
+        , parseRoute @DeploymentRecordsController
         ]
 
 instance InitControllerContext WebApplication where
@@ -56,6 +58,7 @@ defaultLayout inner = [hsx|
                 <a href={RequirementCandidatesAction} class="text-sm text-gray-600 hover:text-gray-900">Candidates</a>
                 <a href={RequirementsAction} class="text-sm text-gray-600 hover:text-gray-900">Requirements</a>
                 <a href={DecisionRecordsAction} class="text-sm text-gray-600 hover:text-gray-900">Decisions</a>
+                <a href={DeploymentRecordsAction} class="text-sm text-gray-600 hover:text-gray-900">Deployments</a>
                 <div class="ml-auto">
                     <a href={DeleteSessionAction} class="text-sm text-gray-500 hover:text-gray-700">Sign out</a>
                 </div>
diff --git a/Web/Routes.hs b/Web/Routes.hs
index 8ede9d9..2b40237 100644
--- a/Web/Routes.hs
+++ b/Web/Routes.hs
@@ -28,5 +28,8 @@ instance AutoRoute RequirementsController
 -- Decision Records (Phase 3)
 instance AutoRoute DecisionRecordsController
 
+-- Deployment Records (Phase 4)
+instance AutoRoute DeploymentRecordsController
+
 -- Sessions
 instance AutoRoute SessionsController
diff --git a/Web/Types.hs b/Web/Types.hs
index 5dd826f..0d3ec1c 100644
--- a/Web/Types.hs
+++ b/Web/Types.hs
@@ -23,8 +23,9 @@ data HubsController
     | EditHubAction             { hubId :: !(Id Hub) }
     | UpdateHubAction           { hubId :: !(Id Hub) }
     | DeleteHubAction           { hubId :: !(Id Hub) }
-    | TriageDashboardAction     { hubId :: !(Id Hub) }
-    | GovernanceDashboardAction { hubId :: !(Id Hub) }
+    | TriageDashboardAction          { hubId :: !(Id Hub) }
+    | GovernanceDashboardAction      { hubId :: !(Id Hub) }
+    | AntifragilityDashboardAction   { hubId :: !(Id Hub) }
     deriving (Eq, Show, Data)
 
 data WidgetsController
@@ -88,6 +89,15 @@ data DecisionRecordsController
     | DeleteImplementationRefAction     { implementationChangeReferenceId :: !(Id ImplementationChangeReference) }
     deriving (Eq, Show, Data)
 
+data DeploymentRecordsController
+    = DeploymentRecordsAction
+    | ShowDeploymentRecordAction      { deploymentRecordId :: !(Id DeploymentRecord) }
+    | NewDeploymentRecordAction
+    | CreateDeploymentRecordAction
+    | RecordOutcomeSignalAction       { deploymentRecordId :: !(Id DeploymentRecord) }
+    | EvaluateChangeAction            { deploymentRecordId :: !(Id DeploymentRecord) }
+    deriving (Eq, Show, Data)
+
 data SessionsController
     = NewSessionAction
     | CreateSessionAction
diff --git a/Web/View/DecisionRecords/Show.hs b/Web/View/DecisionRecords/Show.hs
index fd7d234..1a05042 100644
--- a/Web/View/DecisionRecords/Show.hs
+++ b/Web/View/DecisionRecords/Show.hs
@@ -6,12 +6,14 @@ import IHP.Prelude
 import IHP.ViewPrelude
 
 data ShowView = ShowView
-    { record       :: !DecisionRecord
-    , policyRefs   :: ![PolicyReference]
-    , implRefs     :: ![ImplementationChangeReference]
-    , mRequirement :: !(Maybe Requirement)
-    , mCandidate   :: !(Maybe RequirementCandidate)
-    , users        :: ![User]
+    { record            :: !DecisionRecord
+    , policyRefs        :: ![PolicyReference]
+    , implRefs          :: ![ImplementationChangeReference]
+    , deploymentRecords :: ![DeploymentRecord]
+    , evaluations       :: ![ChangeEvaluation]
+    , mRequirement      :: !(Maybe Requirement)
+    , mCandidate        :: !(Maybe RequirementCandidate)
+    , users             :: ![User]
     }
 
 instance View ShowView where
@@ -92,6 +94,24 @@ instance View ShowView where
                 </form>
             </div>
 
+            <!-- Deployments -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <div class="flex items-center justify-between mb-3">
+                    <h2 class="text-sm font-semibold text-gray-700">Deployments</h2>
+                    {if null implRefs
+                        then mempty
+                        else [hsx|
+                            <a href={(pathTo NewDeploymentRecordAction) <> "?decisionId=" <> show record.id}
+                               class="text-xs border border-indigo-300 text-indigo-600 px-3 py-1 rounded hover:bg-indigo-50">
+                                New Deployment
+                            </a>
+                        |]}
+                </div>
+                {if null deploymentRecords
+                    then [hsx|<p class="text-sm text-gray-400">No deployments recorded yet.</p>|]
+                    else [hsx|{forEach deploymentRecords (renderDeploymentRow evaluations)}|]}
+            </div>
+
             <!-- Implementation references -->
             <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
                 <h2 class="text-sm font-semibold text-gray-700 mb-3">Implementation References</h2>
@@ -201,6 +221,36 @@ systemBadgeClass "linear" = "bg-violet-100 text-violet-800"
 systemBadgeClass "jira"   = "bg-blue-100 text-blue-800"
 systemBadgeClass _        = "bg-gray-100 text-gray-600"
 
+renderDeploymentRow :: [ChangeEvaluation] -> DeploymentRecord -> Html
+renderDeploymentRow evals dr = [hsx|
+    <div class="flex items-center justify-between py-2 border-b border-gray-100 last:border-0">
+        <div class="flex items-center gap-2 text-sm">
+            <a href={ShowDeploymentRecordAction { deploymentRecordId = dr.id }}
+               class="font-mono text-indigo-600 hover:text-indigo-800">{dr.versionRef}</a>
+            <span class="text-xs text-gray-400">{show dr.deployedAt}</span>
+        </div>
+        {maybe mempty renderEvalSummary mEval}
+    </div>
+|]
+  where
+    mEval = find (\e -> e.deploymentId == dr.id) evals
+
+renderEvalSummary :: ChangeEvaluation -> Html
+renderEvalSummary ev = [hsx|
+    <span class={scoreClass ev.score <> " text-xs px-2 py-0.5 rounded font-medium"}>
+        {starsFor ev.score}
+    </span>
+|]
+
+starsFor :: Int16 -> Text
+starsFor n = pack (Prelude.replicate (fromIntegral n) '★') <> pack (Prelude.replicate (5 - fromIntegral n) '☆')
+
+scoreClass :: Int16 -> Text
+scoreClass n
+    | n <= 2    = "bg-red-100 text-red-800"
+    | n == 3    = "bg-yellow-100 text-yellow-800"
+    | otherwise = "bg-green-100 text-green-800"
+
 userName :: [User] -> Maybe (Id User) -> Text
 userName _     Nothing    = "—"
 userName users (Just uid) = maybe "(unknown)" (.name) (find (\u -> u.id == uid) users)
diff --git a/Web/View/DeploymentRecords/Index.hs b/Web/View/DeploymentRecords/Index.hs
new file mode 100644
index 0000000..b263992
--- /dev/null
+++ b/Web/View/DeploymentRecords/Index.hs
@@ -0,0 +1,86 @@
+module Web.View.DeploymentRecords.Index where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data IndexView = IndexView
+    { records     :: ![DeploymentRecord]
+    , decisions   :: ![DecisionRecord]
+    , signals     :: ![OutcomeSignal]
+    , evaluations :: ![ChangeEvaluation]
+    }
+
+instance View IndexView where
+    html IndexView { .. } = [hsx|
+        <div class="flex items-center justify-between mb-6">
+            <h1 class="text-2xl font-semibold">Deployments</h1>
+            <a href={NewDeploymentRecordAction}
+               class="text-sm bg-indigo-600 text-white px-4 py-2 rounded hover:bg-indigo-700">
+                New Deployment
+            </a>
+        </div>
+
+        {if null records
+            then [hsx|<p class="text-gray-500 text-sm">No deployment records yet.</p>|]
+            else renderTable records decisions signals evaluations}
+    |]
+
+renderTable :: [DeploymentRecord] -> [DecisionRecord] -> [OutcomeSignal] -> [ChangeEvaluation] -> Html
+renderTable records decisions signals evaluations = [hsx|
+    <div class="bg-white rounded-lg border border-gray-200 overflow-hidden">
+        <table class="w-full text-sm">
+            <thead class="bg-gray-50 border-b border-gray-200">
+                <tr>
+                    <th class="text-left px-4 py-3 font-semibold text-gray-600">Decision</th>
+                    <th class="text-left px-4 py-3 font-semibold text-gray-600">Version</th>
+                    <th class="text-left px-4 py-3 font-semibold text-gray-600">Deployed At</th>
+                    <th class="text-right px-4 py-3 font-semibold text-gray-600">Signals</th>
+                    <th class="text-right px-4 py-3 font-semibold text-gray-600">Evaluation</th>
+                </tr>
+            </thead>
+            <tbody>
+                {forEach records (renderRow decisions signals evaluations)}
+            </tbody>
+        </table>
+    </div>
+|]
+
+renderRow :: [DecisionRecord] -> [OutcomeSignal] -> [ChangeEvaluation] -> DeploymentRecord -> Html
+renderRow decisions signals evaluations record = [hsx|
+    <tr class="border-b border-gray-100 hover:bg-gray-50 last:border-0">
+        <td class="px-4 py-3">
+            <a href={ShowDeploymentRecordAction { deploymentRecordId = record.id }}
+               class="text-indigo-600 hover:text-indigo-800">{decisionTitle}</a>
+        </td>
+        <td class="px-4 py-3 font-mono text-gray-700">{record.versionRef}</td>
+        <td class="px-4 py-3 text-gray-500">{show record.deployedAt}</td>
+        <td class="px-4 py-3 text-right text-gray-600">{show signalCount}</td>
+        <td class="px-4 py-3 text-right">
+            {maybe [hsx|<span class="text-gray-400">—</span>|] renderScoreBadge mScore}
+        </td>
+    </tr>
+|]
+  where
+    decisionTitle = maybe "(unknown)" (.title) $
+        find (\d -> d.id == record.decisionId) decisions
+    signalCount = length $ filter (\s -> s.deploymentId == record.id) signals
+    mScore :: Maybe Int16
+    mScore = fmap (.score) $ find (\e -> e.deploymentId == record.id) evaluations
+
+renderScoreBadge :: Int16 -> Html
+renderScoreBadge score = [hsx|
+    <span class={scoreClass score <> " text-xs px-2 py-0.5 rounded font-medium"}>
+        {starsFor score}
+    </span>
+|]
+
+starsFor :: Int16 -> Text
+starsFor n = pack (Prelude.replicate (fromIntegral n) '★') <> pack (Prelude.replicate (5 - fromIntegral n) '☆')
+
+scoreClass :: Int16 -> Text
+scoreClass n
+    | n <= 2    = "bg-red-100 text-red-800"
+    | n == 3    = "bg-yellow-100 text-yellow-800"
+    | otherwise = "bg-green-100 text-green-800"
diff --git a/Web/View/DeploymentRecords/New.hs b/Web/View/DeploymentRecords/New.hs
new file mode 100644
index 0000000..bdbbade
--- /dev/null
+++ b/Web/View/DeploymentRecords/New.hs
@@ -0,0 +1,99 @@
+module Web.View.DeploymentRecords.New where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data NewView = NewView
+    { record      :: !DeploymentRecord
+    , decisions   :: ![DecisionRecord]
+    , implRefs    :: ![ImplementationChangeReference]
+    , users       :: ![User]
+    , mDecisionId :: !(Maybe (Id DecisionRecord))
+    }
+
+instance View NewView where
+    html NewView { .. } = [hsx|
+        <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
+            <a href={DeploymentRecordsAction} class="hover:text-gray-700">Deployments</a>
+            <span>/</span>
+            <span>New</span>
+        </div>
+
+        <div class="max-w-xl">
+            <h1 class="text-2xl font-semibold mb-6">Record Deployment</h1>
+
+            <form method="POST" action={CreateDeploymentRecordAction}
+                  class="bg-white rounded-lg border border-gray-200 px-6 py-5 space-y-4">
+                {hiddenField "authenticity_token"}
+
+                <div>
+                    <label class="block text-sm font-medium text-gray-700 mb-1">
+                        Decision <span class="text-red-500">*</span>
+                    </label>
+                    <select name="decisionId"
+                            class="w-full text-sm border border-gray-300 rounded px-3 py-2">
+                        {forEach decisions (renderDecisionOption mDecisionId)}
+                    </select>
+                </div>
+
+                <div>
+                    <label class="block text-sm font-medium text-gray-700 mb-1">
+                        Implementation Reference <span class="text-gray-400">(optional)</span>
+                    </label>
+                    <select name="implRefId"
+                            class="w-full text-sm border border-gray-300 rounded px-3 py-2">
+                        <option value="">— none —</option>
+                        {forEach implRefs renderImplRefOption}
+                    </select>
+                </div>
+
+                <div>
+                    <label class="block text-sm font-medium text-gray-700 mb-1">
+                        Version Reference <span class="text-red-500">*</span>
+                    </label>
+                    <input type="text" name="versionRef"
+                           value={record.versionRef}
+                           placeholder="e.g. v1.2.3, git:abc1234, deploy/2026-03-29"
+                           class="w-full text-sm border border-gray-300 rounded px-3 py-2" />
+                    {validationErrorsFor record #versionRef}
+                </div>
+
+                <div>
+                    <label class="block text-sm font-medium text-gray-700 mb-1">
+                        Notes <span class="text-gray-400">(optional)</span>
+                    </label>
+                    <textarea name="notes" rows="3"
+                              class="w-full text-sm border border-gray-300 rounded px-3 py-2">{fromMaybe "" record.notes}</textarea>
+                </div>
+
+                <div class="flex gap-3 pt-2">
+                    <button type="submit"
+                            class="text-sm bg-indigo-600 text-white px-4 py-2 rounded hover:bg-indigo-700">
+                        Record Deployment
+                    </button>
+                    <a href={DeploymentRecordsAction}
+                       class="text-sm border border-gray-300 px-4 py-2 rounded hover:bg-gray-50">
+                        Cancel
+                    </a>
+                </div>
+            </form>
+        </div>
+    |]
+
+renderDecisionOption :: Maybe (Id DecisionRecord) -> DecisionRecord -> Html
+renderDecisionOption mSelected d = [hsx|
+    <option value={show d.id} selected={isSelected}>
+        {d.title} ({d.outcome})
+    </option>
+|]
+  where
+    isSelected = case mSelected of
+        Just sid -> sid == d.id
+        Nothing  -> False
+
+renderImplRefOption :: ImplementationChangeReference -> Html
+renderImplRefOption ref = [hsx|
+    <option value={show ref.id}>{ref.workItemRef} ({ref.system})</option>
+|]
diff --git a/Web/View/DeploymentRecords/Show.hs b/Web/View/DeploymentRecords/Show.hs
new file mode 100644
index 0000000..b3771bb
--- /dev/null
+++ b/Web/View/DeploymentRecords/Show.hs
@@ -0,0 +1,332 @@
+module Web.View.DeploymentRecords.Show where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data PeriodMetrics = PeriodMetrics
+    { eventCount      :: !Int
+    , annotationCount :: !Int
+    , lowCount        :: !Int
+    , mediumCount     :: !Int
+    , highCount       :: !Int
+    , criticalCount   :: !Int
+    }
+
+highCriticalRate :: PeriodMetrics -> Double
+highCriticalRate m
+    | m.annotationCount == 0 = 0
+    | otherwise = fromIntegral (m.highCount + m.criticalCount) / fromIntegral m.annotationCount
+
+data ShowView = ShowView
+    { record       :: !DeploymentRecord
+    , decision     :: !DecisionRecord
+    , mImplRef     :: !(Maybe ImplementationChangeReference)
+    , mRequirement :: !(Maybe Requirement)
+    , mCandidate   :: !(Maybe RequirementCandidate)
+    , mWidget      :: !(Maybe Widget)
+    , signals      :: ![OutcomeSignal]
+    , mEvaluation  :: !(Maybe ChangeEvaluation)
+    , users        :: ![User]
+    , comparison   :: !(Maybe (PeriodMetrics, PeriodMetrics))
+    }
+
+instance View ShowView where
+    html ShowView { .. } = [hsx|
+        <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
+            <a href={DeploymentRecordsAction} class="hover:text-gray-700">Deployments</a>
+            <span>/</span>
+            <span>{record.versionRef}</span>
+        </div>
+
+        <div class="max-w-3xl space-y-6">
+            <!-- Header card -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-5">
+                <div class="flex items-start justify-between mb-3">
+                    <h1 class="text-2xl font-semibold">{record.versionRef}</h1>
+                </div>
+                <div class="text-xs text-gray-400 mb-3">
+                    Deployed at: {show record.deployedAt} ·
+                    Deployed by: {userName users record.deployedBy}
+                </div>
+                {maybe mempty renderNotes record.notes}
+            </div>
+
+            <!-- Decision chain -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-3">Decision Chain</h2>
+                <div class="space-y-2 text-sm">
+                    <div class="flex items-center gap-2">
+                        <span class="text-xs font-semibold text-gray-400 uppercase w-24">Decision</span>
+                        <a href={ShowDecisionRecordAction { decisionRecordId = decision.id }}
+                           class="text-indigo-600 hover:text-indigo-800">{decision.title}</a>
+                        <span class={outcomeClass decision.outcome <> " text-xs px-2 py-0.5 rounded font-medium"}>
+                            {decision.outcome}
+                        </span>
+                    </div>
+                    {maybe mempty renderImplRefRow mImplRef}
+                    {maybe mempty renderRequirementRow mRequirement}
+                    {maybe mempty renderCandidateRow mCandidate}
+                    {maybe mempty renderWidgetRow mWidget}
+                </div>
+            </div>
+
+            <!-- Outcome signals -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-3">Outcome Signals</h2>
+                {if null signals
+                    then [hsx|<p class="text-sm text-gray-400 mb-3">No signals recorded yet.</p>|]
+                    else [hsx|<div class="mb-4">{forEach signals renderSignal}</div>|]}
+                <form method="POST" action={RecordOutcomeSignalAction { deploymentRecordId = record.id }}
+                      class="flex items-end gap-2 mt-2">
+                    {hiddenField "authenticity_token"}
+                    <div>
+                        <label class="text-xs text-gray-500 block mb-1">Signal type</label>
+                        <select name="signalType"
+                                class="text-sm border border-gray-300 rounded px-2 py-1.5">
+                            <option value="improved">improved</option>
+                            <option value="regressed">regressed</option>
+                            <option value="neutral">neutral</option>
+                            <option value="inconclusive">inconclusive</option>
+                        </select>
+                    </div>
+                    <div>
+                        <label class="text-xs text-gray-500 block mb-1">Value (0–100, optional)</label>
+                        <input type="number" name="value" min="0" max="100" step="any"
+                               class="w-24 text-sm border border-gray-300 rounded px-2 py-1.5"
+                               placeholder="—" />
+                    </div>
+                    <button type="submit"
+                            class="text-sm bg-gray-100 border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-200">
+                        Record
+                    </button>
+                </form>
+            </div>
+
+            <!-- Change evaluation -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-3">Change Evaluation</h2>
+                {maybe (renderNoEvaluationForm record.id) renderEvaluation mEvaluation}
+            </div>
+
+            <!-- Pre/post comparison -->
+            {maybe mempty renderComparison comparison}
+        </div>
+    |]
+
+renderNotes :: Text -> Html
+renderNotes notes = [hsx|
+    <div class="mt-2">
+        <p class="text-xs font-semibold text-gray-500 uppercase tracking-wide mb-1">Notes</p>
+        <p class="text-sm text-gray-600 italic">{notes}</p>
+    </div>
+|]
+
+renderImplRefRow :: ImplementationChangeReference -> Html
+renderImplRefRow ref = [hsx|
+    <div class="flex items-center gap-2">
+        <span class="text-xs font-semibold text-gray-400 uppercase w-24">Impl Ref</span>
+        <span class="font-mono text-gray-700">{ref.workItemRef}</span>
+        <span class="text-xs text-gray-400">({ref.system})</span>
+    </div>
+|]
+
+renderRequirementRow :: Requirement -> Html
+renderRequirementRow req = [hsx|
+    <div class="flex items-center gap-2">
+        <span class="text-xs font-semibold text-gray-400 uppercase w-24">Requirement</span>
+        <a href={ShowRequirementAction { requirementId = req.id }}
+           class="text-indigo-600 hover:text-indigo-800">{req.title}</a>
+    </div>
+|]
+
+renderCandidateRow :: RequirementCandidate -> Html
+renderCandidateRow c = [hsx|
+    <div class="flex items-center gap-2">
+        <span class="text-xs font-semibold text-gray-400 uppercase w-24">Candidate</span>
+        <a href={ShowRequirementCandidateAction { requirementCandidateId = c.id }}
+           class="text-indigo-600 hover:text-indigo-800">{c.title}</a>
+    </div>
+|]
+
+renderWidgetRow :: Widget -> Html
+renderWidgetRow w = [hsx|
+    <div class="flex items-center gap-2">
+        <span class="text-xs font-semibold text-gray-400 uppercase w-24">Widget</span>
+        <a href={ShowWidgetAction { widgetId = w.id }}
+           class="text-indigo-600 hover:text-indigo-800">{w.name}</a>
+    </div>
+|]
+
+renderSignal :: OutcomeSignal -> Html
+renderSignal sig = [hsx|
+    <div class="flex items-center gap-3 py-2 border-b border-gray-100 last:border-0">
+        <span class={signalTypeClass sig.signalType <> " text-xs px-2 py-0.5 rounded font-medium"}>
+            {sig.signalType}
+        </span>
+        {maybe mempty renderSignalValue sig.value}
+        <span class="text-xs text-gray-400 ml-auto">{show sig.observedAt}</span>
+    </div>
+|]
+
+renderSignalValue :: Double -> Html
+renderSignalValue v = [hsx|
+    <span class="text-sm text-gray-700 font-mono">{show v}</span>
+|]
+
+renderNoEvaluationForm :: Id DeploymentRecord -> Html
+renderNoEvaluationForm deploymentRecordId = [hsx|
+    <form method="POST" action={EvaluateChangeAction { deploymentRecordId }}
+          class="space-y-3">
+        {hiddenField "authenticity_token"}
+        <div>
+            <label class="block text-xs font-medium text-gray-600 mb-1">
+                Score (1–5) <span class="text-red-500">*</span>
+            </label>
+            <select name="score"
+                    class="text-sm border border-gray-300 rounded px-3 py-1.5">
+                <option value="1">1 ★☆☆☆☆ — very poor</option>
+                <option value="2">2 ★★☆☆☆ — poor</option>
+                <option value="3">3 ★★★☆☆ — neutral</option>
+                <option value="4">4 ★★★★☆ — good</option>
+                <option value="5">5 ★★★★★ — excellent</option>
+            </select>
+        </div>
+        <div>
+            <label class="block text-xs font-medium text-gray-600 mb-1">
+                Rationale <span class="text-red-500">*</span>
+            </label>
+            <textarea name="rationale" rows="2" required
+                      class="w-full text-sm border border-gray-300 rounded px-3 py-1.5"
+                      placeholder="Why this score?"></textarea>
+        </div>
+        <button type="submit"
+                class="text-sm bg-indigo-600 text-white px-4 py-1.5 rounded hover:bg-indigo-700">
+            Evaluate
+        </button>
+    </form>
+|]
+
+renderEvaluation :: ChangeEvaluation -> Html
+renderEvaluation ev = [hsx|
+    <div class="space-y-2">
+        <div class="flex items-center gap-2">
+            <span class={scoreClass ev.score <> " text-base px-2 py-0.5 rounded font-medium"}>
+                {starsFor ev.score}
+            </span>
+        </div>
+        <p class="text-sm text-gray-700">{ev.rationale}</p>
+        <p class="text-xs text-gray-400">{show ev.evaluatedAt}</p>
+    </div>
+|]
+
+renderComparison :: (PeriodMetrics, PeriodMetrics) -> Html
+renderComparison (before, after) = [hsx|
+    <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+        <h2 class="text-sm font-semibold text-gray-700 mb-3">
+            Pre/Post Comparison (±30 days)
+        </h2>
+        <table class="w-full text-sm">
+            <thead class="border-b border-gray-200">
+                <tr>
+                    <th class="text-left py-2 text-xs font-semibold text-gray-500 uppercase tracking-wide">Metric</th>
+                    <th class="text-right py-2 text-xs font-semibold text-gray-500 uppercase tracking-wide">Before</th>
+                    <th class="text-right py-2 text-xs font-semibold text-gray-500 uppercase tracking-wide">After</th>
+                    <th class="text-right py-2 text-xs font-semibold text-gray-500 uppercase tracking-wide">Delta</th>
+                </tr>
+            </thead>
+            <tbody>
+                {renderMetricRow "Interaction events" before.eventCount after.eventCount False}
+                {renderMetricRow "Annotations (total)" before.annotationCount after.annotationCount True}
+                {renderMetricRow "— low severity" before.lowCount after.lowCount True}
+                {renderMetricRow "— medium severity" before.mediumCount after.mediumCount True}
+                {renderMetricRow "— high severity" before.highCount after.highCount True}
+                {renderMetricRow "— critical severity" before.criticalCount after.criticalCount True}
+                {renderRateRow before after}
+            </tbody>
+        </table>
+    </div>
+|]
+
+renderMetricRow :: Text -> Int -> Int -> Bool -> Html
+renderMetricRow label b a lowerIsBetter = [hsx|
+    <tr class="border-b border-gray-50">
+        <td class="py-2 text-gray-600">{label}</td>
+        <td class="py-2 text-right text-gray-700">{showNA b}</td>
+        <td class="py-2 text-right text-gray-700">{showNA a}</td>
+        <td class="py-2 text-right">
+            <span class={deltaClass (a - b) lowerIsBetter}>{showDelta (a - b)}</span>
+        </td>
+    </tr>
+|]
+  where
+    showNA n = if n == 0 then "—" else show n
+    showDelta d
+        | d == 0    = "—"
+        | d > 0     = "+" <> show d
+        | otherwise = show d
+
+renderRateRow :: PeriodMetrics -> PeriodMetrics -> Html
+renderRateRow before after = [hsx|
+    <tr>
+        <td class="py-2 text-gray-600 font-medium">High/critical rate</td>
+        <td class="py-2 text-right text-gray-700">{formatRate (highCriticalRate before)}</td>
+        <td class="py-2 text-right text-gray-700">{formatRate (highCriticalRate after)}</td>
+        <td class="py-2 text-right">
+            <span class={rateClass (highCriticalRate after) (highCriticalRate before)}>
+                {formatRateDelta (highCriticalRate after - highCriticalRate before)}
+            </span>
+        </td>
+    </tr>
+|]
+  where
+    formatRate r = show (round (r * 100) :: Int) <> "%"
+    formatRateDelta d
+        | abs d < 0.001 = "—"
+        | d > 0         = "+" <> show (round (d * 100) :: Int) <> "%"
+        | otherwise     = show (round (d * 100) :: Int) <> "%"
+
+deltaClass :: Int -> Bool -> Text
+deltaClass 0 _    = "text-gray-400"
+deltaClass d True
+    | d < 0     = "text-green-600 font-medium"
+    | otherwise = "text-red-600 font-medium"
+deltaClass d False
+    | d > 0     = "text-green-600 font-medium"
+    | otherwise = "text-red-600 font-medium"
+
+rateClass :: Double -> Double -> Text
+rateClass after before
+    | abs (after - before) < 0.001 = "text-gray-400"
+    | after < before               = "text-green-600 font-medium"
+    | otherwise                    = "text-red-600 font-medium"
+
+signalTypeClass :: Text -> Text
+signalTypeClass "improved"     = "bg-green-100 text-green-800"
+signalTypeClass "regressed"    = "bg-red-100 text-red-800"
+signalTypeClass "neutral"      = "bg-gray-100 text-gray-600"
+signalTypeClass "inconclusive" = "bg-yellow-100 text-yellow-800"
+signalTypeClass _              = "bg-gray-100 text-gray-600"
+
+outcomeClass :: Text -> Text
+outcomeClass "accepted"  = "bg-green-100 text-green-800"
+outcomeClass "rejected"  = "bg-red-100 text-red-800"
+outcomeClass "deferred"  = "bg-gray-100 text-gray-600"
+outcomeClass "split"     = "bg-purple-100 text-purple-800"
+outcomeClass "merged"    = "bg-indigo-100 text-indigo-800"
+outcomeClass "reframed"  = "bg-orange-100 text-orange-800"
+outcomeClass _           = "bg-gray-100 text-gray-600"
+
+scoreClass :: Int16 -> Text
+scoreClass n
+    | n <= 2    = "bg-red-100 text-red-800"
+    | n == 3    = "bg-yellow-100 text-yellow-800"
+    | otherwise = "bg-green-100 text-green-800"
+
+starsFor :: Int16 -> Text
+starsFor n = pack (Prelude.replicate (fromIntegral n) '★') <> pack (Prelude.replicate (5 - fromIntegral n) '☆')
+
+userName :: [User] -> Maybe (Id User) -> Text
+userName _     Nothing    = "—"
+userName users (Just uid) = maybe "(unknown)" (.name) (find (\u -> u.id == uid) users)
diff --git a/Web/View/Hubs/AntifragilityDashboard.hs b/Web/View/Hubs/AntifragilityDashboard.hs
new file mode 100644
index 0000000..ce5ac9f
--- /dev/null
+++ b/Web/View/Hubs/AntifragilityDashboard.hs
@@ -0,0 +1,259 @@
+module Web.View.Hubs.AntifragilityDashboard where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data AntifragilityDashboardView = AntifragilityDashboardView
+    { hub                 :: !Hub
+    , widgets             :: ![Widget]
+    , allDeployments      :: ![DeploymentRecord]
+    , allDecisions        :: ![DecisionRecord]
+    , allSignals          :: ![OutcomeSignal]
+    , allEvaluations      :: ![ChangeEvaluation]
+    , allImplRefs         :: ![ImplementationChangeReference]
+    , regressionWidgetIds :: ![Id Widget]
+    , recurrenceLeaderboard :: ![(Id Widget, Int)]
+    }
+
+instance View AntifragilityDashboardView where
+    html AntifragilityDashboardView { .. } = [hsx|
+        <div class="mb-6 flex items-center justify-between">
+            <div>
+                <div class="flex items-center gap-2 text-sm text-gray-500 mb-1">
+                    <a href={HubsAction} class="hover:text-gray-700">Hubs</a>
+                    <span>/</span>
+                    <a href={ShowHubAction { hubId = hub.id }} class="hover:text-gray-700">{hub.name}</a>
+                    <span>/</span>
+                    <span>Antifragility</span>
+                </div>
+                <h1 class="text-2xl font-semibold">Antifragility Dashboard — {hub.name}</h1>
+            </div>
+            <div class="flex gap-2">
+                <a href={TriageDashboardAction { hubId = hub.id }}
+                   class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
+                    Triage
+                </a>
+                <a href={GovernanceDashboardAction { hubId = hub.id }}
+                   class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
+                    Governance
+                </a>
+                <a href={ShowHubAction { hubId = hub.id }}
+                   class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
+                    Hub
+                </a>
+            </div>
+        </div>
+
+        <!-- KPI row -->
+        <div class="grid grid-cols-4 gap-4 mb-6">
+            <div class="bg-white rounded-lg border border-gray-200 px-4 py-3 text-center">
+                <div class="text-2xl font-bold">{show (length allDeployments)}</div>
+                <div class="text-xs text-gray-500 mt-0.5">deployments</div>
+            </div>
+            <div class="bg-white rounded-lg border border-gray-200 px-4 py-3 text-center">
+                <div class="text-2xl font-bold">{avgScoreText}</div>
+                <div class="text-xs text-gray-500 mt-0.5">avg evaluation</div>
+            </div>
+            <div class="bg-white rounded-lg border border-gray-200 px-4 py-3 text-center">
+                <div class="text-2xl font-bold">{improvedPctText}</div>
+                <div class="text-xs text-gray-500 mt-0.5">improved signals</div>
+            </div>
+            <div class="bg-red-50 rounded-lg border border-red-200 px-4 py-3 text-center">
+                <div class="text-2xl font-bold text-red-700">{show (length regressionWidgetIds)}</div>
+                <div class="text-xs text-red-500 mt-0.5">regressions</div>
+            </div>
+        </div>
+
+        <!-- Regression alerts -->
+        {if null regressionWidgetIds then mempty else [hsx|
+        <div class="bg-red-50 border border-red-200 rounded-lg px-6 py-4 mb-6">
+            <h2 class="text-sm font-semibold text-red-700 mb-3">⚠ Regression Alerts</h2>
+            <div class="flex flex-wrap gap-2">
+                {forEach regressedWidgets renderRegressedBadge}
+            </div>
+        </div>
+        |]}
+
+        <!-- Open gaps: decisions with impl refs but no deployment -->
+        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5 mb-6">
+            <h2 class="text-sm font-semibold text-gray-700 mb-3">
+                Open Gaps
+                <span class="text-xs font-normal text-gray-400 ml-2">
+                    (decisions with impl refs but no deployment recorded)
+                </span>
+            </h2>
+            {if null openGaps
+                then [hsx|<p class="text-sm text-gray-400">All decisions with impl refs have deployments.</p>|]
+                else [hsx|
+                    <div class="space-y-1">
+                        {forEach openGaps renderGapRow}
+                    </div>
+                |]}
+        </div>
+
+        <!-- Recent deployments -->
+        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5 mb-6">
+            <h2 class="text-sm font-semibold text-gray-700 mb-3">Recent Deployments</h2>
+            {if null recentDeploys
+                then [hsx|<p class="text-sm text-gray-400">No deployments yet.</p>|]
+                else [hsx|
+                    <table class="w-full text-sm">
+                        <thead class="border-b border-gray-100">
+                            <tr>
+                                <th class="text-left py-2 text-xs font-medium text-gray-500">Version</th>
+                                <th class="text-left py-2 text-xs font-medium text-gray-500">Decision</th>
+                                <th class="text-right py-2 text-xs font-medium text-gray-500">Signals</th>
+                                <th class="text-right py-2 text-xs font-medium text-gray-500">Eval</th>
+                                <th class="text-right py-2 text-xs font-medium text-gray-500">Deployed</th>
+                            </tr>
+                        </thead>
+                        <tbody class="divide-y divide-gray-50">
+                            {forEach recentDeploys (renderDeployRow allDecisions allSignals allEvaluations)}
+                        </tbody>
+                    </table>
+                |]}
+        </div>
+
+        <!-- Recurrence leaderboard -->
+        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5">
+            <h2 class="text-sm font-semibold text-gray-700 mb-3">Recurrence Leaderboard</h2>
+            {if null recurrenceLeaderboard
+                then [hsx|<p class="text-sm text-gray-400">No recurring widgets detected.</p>|]
+                else [hsx|
+                    <table class="w-full text-sm">
+                        <thead class="border-b border-gray-100">
+                            <tr>
+                                <th class="text-left py-2 text-xs font-medium text-gray-500">Widget</th>
+                                <th class="text-right py-2 text-xs font-medium text-gray-500">Cycles</th>
+                            </tr>
+                        </thead>
+                        <tbody class="divide-y divide-gray-50">
+                            {forEach recurrenceLeaderboard (renderRecurrenceRow widgets)}
+                        </tbody>
+                    </table>
+                |]}
+        </div>
+    |]
+  where
+    deployedIds    = map (.id) allDeployments
+    openGaps       = filter (\d -> any (\r -> r.decisionId == d.id) allImplRefs
+                                && not (any (\dp -> dp.decisionId == d.id) allDeployments))
+                            allDecisions
+    recentDeploys  = take 20 (sortByDesc (.deployedAt) allDeployments)
+    regressedWidgets = filter (\w -> w.id `elem` regressionWidgetIds) widgets
+    avgScoreText
+        | null allEvaluations = "—"
+        | otherwise =
+            let avg = fromIntegral (sum (map (.score) allEvaluations)) / fromIntegral (length allEvaluations) :: Double
+            in show (round avg :: Int) <> "/5"
+    improvedPctText
+        | null allSignals = "—"
+        | otherwise =
+            let improved = length (filter (\s -> s.signalType == "improved") allSignals)
+                pct = (fromIntegral improved * 100 `div` length allSignals) :: Int
+            in show pct <> "%"
+
+sortByDesc :: Ord b => (a -> b) -> [a] -> [a]
+sortByDesc f = sortBy (\a b -> compare (f b) (f a))
+
+renderRegressedBadge :: Widget -> Html
+renderRegressedBadge w = [hsx|
+    <a href={ShowWidgetAction { widgetId = w.id }}
+       class="text-xs bg-red-100 text-red-800 border border-red-300 rounded px-2 py-1 hover:bg-red-200">
+        {w.name}
+    </a>
+|]
+
+renderGapRow :: DecisionRecord -> Html
+renderGapRow d = [hsx|
+    <div class="flex items-center justify-between py-1.5 text-sm">
+        <a href={ShowDecisionRecordAction { decisionRecordId = d.id }}
+           class="text-indigo-600 hover:text-indigo-800">{d.title}</a>
+        <span class={outcomeClass d.outcome <> " text-xs px-2 py-0.5 rounded font-medium"}>
+            {d.outcome}
+        </span>
+    </div>
+|]
+
+renderDeployRow :: [DecisionRecord] -> [OutcomeSignal] -> [ChangeEvaluation] -> DeploymentRecord -> Html
+renderDeployRow decisions signals evals dr = [hsx|
+    <tr>
+        <td class="py-2 pr-4">
+            <a href={ShowDeploymentRecordAction { deploymentRecordId = dr.id }}
+               class="font-mono text-indigo-600 hover:text-indigo-800">{dr.versionRef}</a>
+        </td>
+        <td class="py-2 pr-4 text-gray-600">{decisionTitle}</td>
+        <td class="py-2 pr-4 text-right">
+            {renderSignalSummary drSignals}
+        </td>
+        <td class="py-2 pr-4 text-right">
+            {maybe [hsx|<span class="text-gray-400 text-xs">—</span>|] renderEvalBadge mScore}
+        </td>
+        <td class="py-2 text-right text-xs text-gray-400">{show dr.deployedAt}</td>
+    </tr>
+|]
+  where
+    decisionTitle = maybe "—" (.title) (find (\d -> d.id == dr.decisionId) decisions)
+    drSignals     = filter (\s -> s.deploymentId == dr.id) signals
+    mScore        = fmap (.score) (find (\e -> e.deploymentId == dr.id) evals)
+
+renderSignalSummary :: [OutcomeSignal] -> Html
+renderSignalSummary [] = [hsx|<span class="text-gray-400 text-xs">—</span>|]
+renderSignalSummary signals = [hsx|
+    <div class="flex gap-1 justify-end">
+        {forEach (take 3 signals) (\s -> [hsx|
+            <span class={signalDot s.signalType}></span>
+        |])}
+    </div>
+|]
+
+signalDot :: Text -> Text
+signalDot "improved"     = "inline-block w-2 h-2 rounded-full bg-green-500"
+signalDot "regressed"    = "inline-block w-2 h-2 rounded-full bg-red-500"
+signalDot "neutral"      = "inline-block w-2 h-2 rounded-full bg-gray-400"
+signalDot "inconclusive" = "inline-block w-2 h-2 rounded-full bg-yellow-400"
+signalDot _              = "inline-block w-2 h-2 rounded-full bg-gray-300"
+
+renderEvalBadge :: Int16 -> Html
+renderEvalBadge score = [hsx|
+    <span class={scoreClass score <> " text-xs px-2 py-0.5 rounded font-medium"}>
+        {show score}/5
+    </span>
+|]
+
+renderRecurrenceRow :: [Widget] -> (Id Widget, Int) -> Html
+renderRecurrenceRow widgets (wid, count) = [hsx|
+    <tr>
+        <td class="py-2">
+            {maybe [hsx|<span class="text-gray-500">—</span>|] renderWidgetLink mWidget}
+        </td>
+        <td class="py-2 text-right">
+            <span class="text-sm font-semibold text-yellow-700">⟳ {show count}</span>
+        </td>
+    </tr>
+|]
+  where
+    mWidget = find (\w -> w.id == wid) widgets
+
+renderWidgetLink :: Widget -> Html
+renderWidgetLink w = [hsx|
+    <a href={ShowWidgetAction { widgetId = w.id }}
+       class="text-indigo-600 hover:text-indigo-800">{w.name}</a>
+|]
+
+outcomeClass :: Text -> Text
+outcomeClass "accepted"  = "bg-green-100 text-green-800"
+outcomeClass "rejected"  = "bg-red-100 text-red-800"
+outcomeClass "deferred"  = "bg-gray-100 text-gray-600"
+outcomeClass "split"     = "bg-purple-100 text-purple-800"
+outcomeClass "merged"    = "bg-indigo-100 text-indigo-800"
+outcomeClass "reframed"  = "bg-orange-100 text-orange-800"
+outcomeClass _           = "bg-gray-100 text-gray-600"
+
+scoreClass :: Int16 -> Text
+scoreClass n
+    | n <= 2    = "bg-red-100 text-red-800"
+    | n == 3    = "bg-yellow-100 text-yellow-800"
+    | otherwise = "bg-green-100 text-green-800"
diff --git a/Web/View/Hubs/GovernanceDashboard.hs b/Web/View/Hubs/GovernanceDashboard.hs
index 3c9b286..8d20345 100644
--- a/Web/View/Hubs/GovernanceDashboard.hs
+++ b/Web/View/Hubs/GovernanceDashboard.hs
@@ -6,13 +6,14 @@ import IHP.Prelude
 import IHP.ViewPrelude
 
 data GovernanceDashboardView = GovernanceDashboardView
-    { hub              :: !Hub
-    , widgets          :: ![Widget]
-    , allCandidates    :: ![RequirementCandidate]
-    , allRequirements  :: ![Requirement]
-    , recentDecisions  :: ![DecisionRecord]
-    , allDecisions     :: ![DecisionRecord]
-    , allAnnotations   :: ![Annotation]
+    { hub                 :: !Hub
+    , widgets             :: ![Widget]
+    , allCandidates       :: ![RequirementCandidate]
+    , allRequirements     :: ![Requirement]
+    , recentDecisions     :: ![DecisionRecord]
+    , allDecisions        :: ![DecisionRecord]
+    , allAnnotations      :: ![Annotation]
+    , regressionWidgetIds :: ![Id Widget]
     }
 
 instance View GovernanceDashboardView where
@@ -33,6 +34,10 @@ instance View GovernanceDashboardView where
                    class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
                     Triage Dashboard
                 </a>
+                <a href={AntifragilityDashboardAction { hubId = hub.id }}
+                   class="text-sm border border-green-300 text-green-700 px-3 py-1.5 rounded hover:bg-green-50">
+                    Antifragility
+                </a>
                 <a href={ShowHubAction { hubId = hub.id }}
                    class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
                     Hub Overview
@@ -40,11 +45,24 @@ instance View GovernanceDashboardView where
             </div>
         </div>
 
-        <!-- KPI row: decision outcomes -->
-        <div class="grid grid-cols-3 gap-4 mb-6 sm:grid-cols-6">
+        <!-- KPI row: decision outcomes + regression -->
+        <div class="grid grid-cols-3 gap-4 mb-4 sm:grid-cols-7">
             {forEach outcomeList (\o -> renderKpiCard o (countOutcome allDecisions o))}
+            <div class="bg-red-50 text-red-800 rounded-lg px-4 py-3 text-center">
+                <div class="text-2xl font-bold">{show (length regressionWidgetIds)}</div>
+                <div class="text-xs mt-0.5 opacity-75">regressions</div>
+            </div>
         </div>
 
+        {if null regressionWidgetIds then mempty else [hsx|
+        <div class="bg-red-50 border border-red-200 rounded-lg px-6 py-4 mb-6">
+            <h2 class="text-sm font-semibold text-red-700 mb-2">⚠ Regressed Widgets</h2>
+            <div class="flex flex-wrap gap-2">
+                {forEach regressedWidgets renderRegressedBadge}
+            </div>
+        </div>
+        |]}
+
         <!-- Open requirements awaiting decision -->
         <div class="bg-white rounded-lg border border-gray-200 px-6 py-5 mb-6">
             <h2 class="text-sm font-semibold text-gray-700 mb-3">
@@ -99,7 +117,8 @@ instance View GovernanceDashboardView where
         </div>
     |]
   where
-    awaitingDecision = filter (isAwaitingDecision allDecisions) allRequirements
+    awaitingDecision  = filter (isAwaitingDecision allDecisions) allRequirements
+    regressedWidgets  = filter (\w -> w.id `elem` regressionWidgetIds) widgets
 
 outcomeList :: [Text]
 outcomeList = ["accepted", "rejected", "deferred", "split", "merged", "reframed"]
@@ -192,6 +211,14 @@ renderCoverageRow annotations candidates requirements decisions w = [hsx|
     widgetReqIds = map (.id) (filter (\r -> r.sourceCandidateId `elem` candidateIds) requirements)
     hasDecision  = any (\d -> d.requirementId `elem` map Just widgetReqIds) decisions
 
+renderRegressedBadge :: Widget -> Html
+renderRegressedBadge w = [hsx|
+    <a href={ShowWidgetAction { widgetId = w.id }}
+       class="text-xs bg-red-100 text-red-800 border border-red-300 rounded px-2 py-1 hover:bg-red-200">
+        {w.name}
+    </a>
+|]
+
 coverageMark :: Bool -> Html
 coverageMark True  = [hsx|<span class="text-green-600 font-bold">✓</span>|]
 coverageMark False = [hsx|<span class="text-gray-300">✗</span>|]
diff --git a/Web/View/Hubs/Show.hs b/Web/View/Hubs/Show.hs
index 7aa6f50..a939ffe 100644
--- a/Web/View/Hubs/Show.hs
+++ b/Web/View/Hubs/Show.hs
@@ -37,6 +37,10 @@ instance View ShowView where
                        class="text-sm border border-purple-300 text-purple-700 px-3 py-1.5 rounded hover:bg-purple-50">
                         Governance Dashboard
                     </a>
+                    <a href={AntifragilityDashboardAction { hubId = hub.id }}
+                       class="text-sm border border-green-300 text-green-700 px-3 py-1.5 rounded hover:bg-green-50">
+                        Antifragility
+                    </a>
                     <a href={EditHubAction { hubId = hub.id }}
                        class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
                         Edit
diff --git a/Web/View/Widgets/Show.hs b/Web/View/Widgets/Show.hs
index f3df956..0d42e9c 100644
--- a/Web/View/Widgets/Show.hs
+++ b/Web/View/Widgets/Show.hs
@@ -7,11 +7,14 @@ import IHP.ViewPrelude
 import Application.Helper.View (widgetEnvelope)
 
 data ShowView = ShowView
-    { widget      :: !Widget
-    , hub         :: !Hub
-    , versions    :: ![WidgetVersion]
-    , events      :: ![InteractionEvent]
-    , annotations :: ![Annotation]
+    { widget        :: !Widget
+    , hub           :: !Hub
+    , versions      :: ![WidgetVersion]
+    , events        :: ![InteractionEvent]
+    , annotations   :: ![Annotation]
+    , recentSignals :: ![OutcomeSignal]
+    , isRegressed   :: !Bool
+    , cycleCount    :: !Int
     }
 
 instance View ShowView where
@@ -24,6 +27,24 @@ instance View ShowView where
             <span>{widget.name}</span>
         </div>
 
+        {if cycleCount >= 2 then [hsx|
+        <div class="mb-2 flex items-center gap-2 bg-yellow-50 border border-yellow-200 rounded-lg px-4 py-2">
+            <span class="text-yellow-700 font-semibold text-sm">⟳ {show cycleCount} cycles</span>
+            <span class="text-yellow-600 text-xs">
+                Recurring friction — this widget has been through {show cycleCount} improvement cycles.
+            </span>
+        </div>
+        |] else mempty}
+
+        {if isRegressed then [hsx|
+        <div class="mb-4 flex items-center gap-2 bg-red-50 border border-red-200 rounded-lg px-4 py-3">
+            <span class="text-red-600 font-semibold text-sm">⚠ Regression detected</span>
+            <span class="text-red-500 text-xs">
+                This widget had an improved signal but has since received high/critical annotations.
+            </span>
+        </div>
+        |] else mempty}
+
         {widgetEnvelope widget [hsx|
             <div class="flex items-center justify-between mb-4">
                 <div>
@@ -95,6 +116,15 @@ instance View ShowView where
             </div>
         </section>
 
+        {if null recentSignals then mempty else [hsx|
+        <section class="mb-8">
+            <h2 class="text-lg font-medium mb-3">Recent Outcome Signals</h2>
+            <div class="bg-white rounded-lg border border-gray-200 divide-y divide-gray-100">
+                {forEach recentSignals renderSignalRow}
+            </div>
+        </section>
+        |]}
+
         <section>
             <h2 class="text-lg font-medium mb-3">Version History</h2>
             <div class="bg-white rounded-lg border border-gray-200 overflow-hidden">
@@ -160,3 +190,21 @@ renderCategoryRow (cat, count) = [hsx|
         <span class="font-semibold">{show count}</span>
     </div>
 |]
+
+renderSignalRow :: OutcomeSignal -> Html
+renderSignalRow sig = [hsx|
+    <div class="flex items-center gap-3 px-4 py-3 text-sm">
+        <span class={signalTypeClass sig.signalType <> " text-xs px-2 py-0.5 rounded font-medium"}>
+            {sig.signalType}
+        </span>
+        {maybe mempty (\v -> [hsx|<span class="font-mono text-gray-700">{show v}</span>|]) sig.value}
+        <span class="text-xs text-gray-400 ml-auto">{show sig.observedAt}</span>
+    </div>
+|]
+
+signalTypeClass :: Text -> Text
+signalTypeClass "improved"     = "bg-green-100 text-green-800"
+signalTypeClass "regressed"    = "bg-red-100 text-red-800"
+signalTypeClass "neutral"      = "bg-gray-100 text-gray-600"
+signalTypeClass "inconclusive" = "bg-yellow-100 text-yellow-800"
+signalTypeClass _              = "bg-gray-100 text-gray-600"
diff --git a/docs/phase4-summary.md b/docs/phase4-summary.md
new file mode 100644
index 0000000..2ccb294
--- /dev/null
+++ b/docs/phase4-summary.md
@@ -0,0 +1,81 @@
+# Phase 4 Summary — Outcome Observation and Antifragility Loop
+
+**Workplan:** IHUB-WP-0004
+**Completed:** 2026-03-29
+**Phase:** 4 of 8 in the IHF specification
+
+---
+
+## What Was Built
+
+Phase 4 closes the IHF improvement loop by connecting deployed versions to observed outcomes. The full chain is now traversable:
+
+```
+Widget → InteractionEvent / Annotation
+       → RequirementCandidate → Requirement
+       → DecisionRecord → ImplementationChangeReference
+       → DeploymentRecord
+       → OutcomeSignal  ←  ChangeEvaluation
+       → RegressionDetection / RecurrenceTracking
+```
+
+### T01 — Schema
+
+Three new tables:
+- **`deployment_records`** — immutable link from a decision to a deployed version (`version_ref`, `deployed_at`, `deployed_by`, `notes`)
+- **`outcome_signals`** — append-only observations of widget behaviour post-deployment (`signal_type`, `value`, `observed_at`); PostgreSQL trigger prevents UPDATE/DELETE
+- **`change_evaluations`** — one score (1–5) per deployment with rationale; UNIQUE constraint on `deployment_id`
+
+### T02 — DeploymentRecords Controller and Views
+
+`DeploymentRecordsController` with index, show, new, create (no update/delete — immutable by convention). Decision show page includes a "New Deployment" button (gated on having at least one implementation reference). Deployment show page renders the full decision chain: Decision → ImplRef → Requirement → Candidate → Widget.
+
+### T03 — OutcomeSignal Capture
+
+`RecordOutcomeSignalAction` (POST from deployment show page). Signal types: `improved`, `regressed`, `neutral`, `inconclusive` with color coding (green/red/gray/yellow). Widget show page lists the last 10 signals across all deployments.
+
+### T04 — Pre/Post Comparison
+
+Comparison panel on the deployment show page. Computes interaction event counts and annotation severity distribution for the 30-day window before vs. after `deployed_at`. Delta column: green if annotation rate decreased, red if increased. Works with no post-deployment data (shows "—").
+
+### T05 — Regression Detection
+
+`regressedWidgetIds` pure function in `Application.Helper.Controller`. A regression is: any widget with an `OutcomeSignal(improved)` followed (> 1 day later) by a new `Annotation(severity=high|critical)`. Regression badge on widget show page; regression count and widget list on governance dashboard; prominent alerts panel on antifragility dashboard.
+
+### T06 — ChangeEvaluation
+
+`EvaluateChangeAction` (POST). Idempotent — second attempt on same deployment redirects with "Already evaluated" message. Score 1–5 rendered as ★ stars with color (1–2 red, 3 yellow, 4–5 green). Evaluation summary shown on decision show page alongside each deployment row.
+
+### T07 — Recurrence Tracking
+
+`widgetCycleCounts` function computes completed improvement cycles per widget (cycle = accepted candidate → requirement → decision → deployment → new candidate). Cycle count badge ("⟳ N cycles") on widget show page for cycle_count ≥ 2. Top-10 leaderboard on antifragility dashboard.
+
+### T08 — Antifragility Dashboard
+
+`AntifragilityDashboardAction` wrapped with `autoRefresh do`. Five panels:
+1. **KPI row**: total deployments / avg evaluation score / % improved signals / regression count
+2. **Regression alerts**: widgets currently in regression (red panel, links to widget show pages)
+3. **Open gaps**: decisions with impl refs but no deployment record yet
+4. **Recent deployments** (last 20): version ref, decision title, signal dots, evaluation score
+5. **Recurrence leaderboard**: top 10 widgets by cycle count
+
+Linked from hub show page (green "Antifragility" button) and governance dashboard.
+
+---
+
+## Known Limitations
+
+- **Pre/post comparison uses Haskell-side filtering**, not SQL aggregates. For production use with large datasets, replace `computeComparison` with `[typedSql|...|]` queries (IHP v1.5 typed quasiquoter).
+- **Regression detection is a heuristic**. It detects any high/critical annotation after an improved signal — it does not distinguish whether the annotation relates to the same aspect of the widget that was improved.
+- **Cycle count requires a strict data chain**. Cycles are only counted when the full candidate→requirement→decision→deployment chain exists. Partial cycles (e.g., a decision without a deployment) are not counted.
+- **No ML in Phase 4**. All scoring and detection is rule-based. Agent-assisted distillation begins in Phase 5.
+
+---
+
+## Phase 5 Readiness
+
+Phase 5 (Agent-Assisted Distillation) can now build on:
+- `OutcomeSignal` as evidence input for agent distillation
+- `ChangeEvaluation` scores as feedback signal for agent learning
+- `RegressionDetection` results as priority signal for agent attention
+- The full traceability chain from widget to outcome is traversable in one hop
diff --git a/workplans/IHUB-WP-0004-ihf-phase4-outcome-observation-and-antifragility.md b/workplans/IHUB-WP-0004-ihf-phase4-outcome-observation-and-antifragility.md
index 44465fb..a716631 100644
--- a/workplans/IHUB-WP-0004-ihf-phase4-outcome-observation-and-antifragility.md
+++ b/workplans/IHUB-WP-0004-ihf-phase4-outcome-observation-and-antifragility.md
@@ -4,7 +4,7 @@ type: workplan
 title: "IHF Phase 4 — Outcome Observation and Antifragility Loop"
 domain: inter_hub
 repo: inter-hub
-status: active
+status: done
 owner: custodian
 topic_slug: inter_hub
 created: "2026-03-29"
@@ -69,7 +69,7 @@ Reference: `docs/ihp-overview.md`, `docs/ihp-data-and-queries.md`,
 
 ```task
 id: IHUB-WP-0004-T01
-status: todo
+status: done
 priority: high
 state_hub_task_id: "4d0aa6d5-f291-4053-a487-8c64627f8271"
 ```
@@ -149,7 +149,7 @@ CREATE INDEX change_evaluations_deployment_id_idx ON change_evaluations (deploym
 
 ```task
 id: IHUB-WP-0004-T02
-status: todo
+status: done
 priority: high
 state_hub_task_id: "4932b036-fe91-4146-9b35-7d3031894c2d"
 ```
@@ -175,7 +175,7 @@ full decision → requirement → widget chain.
 
 ```task
 id: IHUB-WP-0004-T03
-status: todo
+status: done
 priority: high
 state_hub_task_id: "8b39bbb3-4129-4acc-97ac-38ecfcfd7c88"
 ```
@@ -202,7 +202,7 @@ append-only constraint verified; color roles applied consistently.
 
 ```task
 id: IHUB-WP-0004-T04
-status: todo
+status: done
 priority: high
 state_hub_task_id: "27c4de52-755a-40e7-bef3-986fe4470f7c"
 ```
@@ -226,7 +226,7 @@ direction color-coded correctly; works with no post-deployment data (shows "—"
 
 ```task
 id: IHUB-WP-0004-T05
-status: todo
+status: done
 priority: high
 state_hub_task_id: "844a828b-b7d7-4822-becc-b377c08c673a"
 ```
@@ -253,7 +253,7 @@ affected widgets; count accurate on dashboard.
 
 ```task
 id: IHUB-WP-0004-T06
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "391c6136-baea-417a-9291-5ba9f633e03f"
 ```
@@ -275,7 +275,7 @@ correct color in all views.
 
 ```task
 id: IHUB-WP-0004-T07
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "6a5eea23-4e73-441a-ab93-49f5b76bf3ea"
 ```
@@ -300,7 +300,7 @@ visible on widget show page.
 
 ```task
 id: IHUB-WP-0004-T08
-status: todo
+status: done
 priority: high
 state_hub_task_id: "e5c65c77-c757-49a6-a8e9-99c8d3503f59"
 ```
@@ -326,7 +326,7 @@ All five panels render with correct data.
 
 ```task
 id: IHUB-WP-0004-T09
-status: todo
+status: done
 priority: high
 state_hub_task_id: "1dda0a32-4913-4007-a9f4-1d86761a8cf1"
 ```