diff --git a/AGENTS.md b/AGENTS.md
index 84a82ee..5628d19 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -101,6 +101,28 @@ curl -s -X PATCH "http://127.0.0.1:8000/tasks/<task_id>" \
 
 ---
 
+## Issue-core emission (`ISSUE_SINK_TYPE=rest`)
+
+activity-core emits tasks to issue-core via `IssueCoreRestSink` (`src/activity_core/issue_sink.py`).
+
+**Do not request `ISSUE_CORE_API_KEY` from ops-warden** — ops-warden issues SSH
+certs only. For routing: `warden route show activity-core-issue-sink --json`.
+
+| Env var | Purpose |
+| --- | --- |
+| `ISSUE_CORE_URL` | issue-core base URL (default `http://127.0.0.1:8765`) |
+| `ISSUE_CORE_API_KEY` | Shared ingestion key — sent as `Authorization: Bearer` |
+| `ISSUE_SINK_TYPE` | `rest` (live POST) or `null` (dry-run; Railiance default) |
+
+**Local dev:** generate one key, export on both activity-core and issue-core
+processes. See `docs/issue-core-emission-boundary.md` and issue-core `README.md`.
+Use `default: local` in issue-core `backends.json` for local smoke.
+
+**Production:** inject the same key on both sides via OpenBao/K8s (coordinate
+`railiance-platform` when the canonical path ships).
+
+---
+
 ## Workplan Convention (ADR-001)
 
 Work items originate as files in this repo — not in the hub. The hub is a