diff --git a/registry/routing/catalog.yaml b/registry/routing/catalog.yaml
index 711c532..69ac651 100644
--- a/registry/routing/catalog.yaml
+++ b/registry/routing/catalog.yaml
@@ -103,6 +103,17 @@ entries:
     reviewed: "2026-06-18"
     status: active
 
+  - id: activity-core-issue-sink
+    title: activity-core IssueSink → issue-core REST emission
+    need_keywords: [activity-core, issue-sink, issue-core, emission, issue_core_url, issue_core_api_key, tasks, ingest, rest, issuesink]
+    owner_repo: activity-core
+    subsystem: activity-core + issue-core
+    warden_executes: false
+    wiki_ref: wiki/playbooks/activity-core-issue-sink.md#worker-checklist
+    canon_ref: net-kingdom/docs/platform-identity-security-architecture.md
+    reviewed: "2026-06-18"
+    status: active
+
   # --- draft: owner path not yet shipped; hidden from default lookup ---
   - id: issue-core-ingestion-api-key
     title: issue-core ingestion API key (OpenBao path TBD)
diff --git a/wiki/CredentialRouting.md b/wiki/CredentialRouting.md
index ad61669..f3c6d60 100644
--- a/wiki/CredentialRouting.md
+++ b/wiki/CredentialRouting.md
@@ -86,6 +86,7 @@ executes.
 | `key-cape-oidc-login` | "key-cape / Keycloak owns identity" | Authenticate via IAM Profile |
 | `ops-bridge-tunnel` | "ops-bridge owns transport — supply a `cert_command`" | Open the tunnel with ops-bridge |
 | `railiance-infra-principals` | "railiance-infra deploys host principals" | Run the infra Ansible |
+| `activity-core-issue-sink` | "activity-core + issue-core own emission — pair `ISSUE_CORE_*` env vars" | See `wiki/playbooks/activity-core-issue-sink.md` |
 
 ops-warden answers *where + who*; the worker acts on the owning system. ops-warden
 never performs the non-SSH step on the worker's behalf.
diff --git a/wiki/playbooks/activity-core-issue-sink.md b/wiki/playbooks/activity-core-issue-sink.md
new file mode 100644
index 0000000..8a0bb4b
--- /dev/null
+++ b/wiki/playbooks/activity-core-issue-sink.md
@@ -0,0 +1,67 @@
+# activity-core IssueSink → issue-core REST emission
+
+Date: 2026-06-18
+
+Pointer playbook for agents wiring **activity-core** task emission to the
+**issue-core** REST ingestion endpoint. Authoritative contracts live in the
+owner repos — this page is a checklist and index only (no-double-source rule).
+
+---
+
+## Owners
+
+| Concern | Owner repo | Authoritative doc |
+| --- | --- | --- |
+| IssueSink consumer (`IssueCoreRestSink`) | `activity-core` | `docs/issue-core-emission-boundary.md` |
+| Ingestion server (`POST /issues/`) | `issue-core` | `README.md` — REST Ingestion Server |
+| Production secret injection (K8s/OpenBao) | `railiance-platform` | catalog id `issue-core-ingestion-api-key` (draft until path ships) |
+
+---
+
+## Do not ask ops-warden
+
+`ISSUE_CORE_API_KEY` is a **shared ingestion key** between activity-core and
+issue-core. It is not an SSH certificate and ops-warden does not vend it.
+
+- Generic API-key routing: `warden route show openbao-api-key --json`
+- This emission lane: `warden route show activity-core-issue-sink --json`
+- State Hub messages to `ops-warden` expecting a key value will not succeed.
+
+Never paste key values into Git, State Hub, workplans, logs, or agent chat.
+
+---
+
+## Worker checklist
+
+1. **Confirm sink mode** — `ISSUE_SINK_TYPE=rest` for live emission; `null` for
+   dry-run (Railiance production default today). See activity-core `SCOPE.md`.
+2. **Pair env vars on both sides** (same value):
+   - `ISSUE_CORE_URL` — e.g. `http://127.0.0.1:8765` locally
+   - `ISSUE_CORE_API_KEY` — shared secret; activity-core sends
+     `Authorization: Bearer <key>`; issue-core validates on ingest
+3. **Local dev** — generate once, export on both processes:
+   ```bash
+   export ISSUE_CORE_API_KEY="$(python3 -c 'import secrets; print(secrets.token_urlsafe(32))')"
+   issue serve --host 127.0.0.1 --port 8765   # issue-core terminal
+   ```
+   Use `default: local` in `~/.config/issue-tracker/backends.json` for local
+   smoke — a remote Gitea default backend will hang on ingest.
+4. **Verify** — `uv run pytest tests/test_issue_sink.py` in activity-core;
+   one live POST should return `201` with `issue_id` (see issue-core README).
+5. **Production** — inject `ISSUE_CORE_API_KEY` via OpenBao/K8s on both
+   deployments; coordinate with `railiance-platform` when the canonical path
+   ships (`issue-core-ingestion-api-key` catalog entry).
+
+### Known contract gap
+
+issue-core requires `triggering_event_id` as a UUID; activity-core cron paths
+may send non-UUID keys (e.g. `"scheduled"`). Event-driven emission with real
+event UUIDs works; align schemas before enabling cron rules against live REST.
+
+---
+
+## See also
+
+- `activity-core/AGENTS.md` — Issue-core emission section
+- `issue-core/AGENTS.md` — REST ingestion API key section
+- `WARDEN-WP-0012` — playbook backlog and promotion gates
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