diff --git a/AGENTS.md b/AGENTS.md
index 8bd0e39..4fce917 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -3,3 +3,16 @@
 
 This version has breaking changes — APIs, conventions, and file structure may all differ from your training data. Read the relevant guide in `node_modules/next/dist/docs/` before writing any code. Heed deprecation notices.
 <!-- END:nextjs-agent-rules -->
+
+## Burden Of Proof
+
+Before declaring work complete, try to disprove the change. Identify the
+strongest realistic failure mode, verify it with a command, test, trace,
+screenshot, audit record, diff, or direct inspection, and include that evidence
+in the final handoff.
+
+Treat `done`, `tests passed`, worker claims, passing happy-path tests, generated
+summaries, and optimistic UI as claims, not proof. Treat unverified assumptions
+as blockers or explicit follow-ups.
+
+Keep this section synchronized with `CLAUDE.md` whenever either file changes.
diff --git a/CLAUDE.md b/CLAUDE.md
index 43c994c..b4ff3e0 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -1 +1,14 @@
 @AGENTS.md
+
+## Burden Of Proof
+
+Before declaring work complete, try to disprove the change. Identify the
+strongest realistic failure mode, verify it with a command, test, trace,
+screenshot, audit record, diff, or direct inspection, and include that evidence
+in the final handoff.
+
+Treat `done`, `tests passed`, worker claims, passing happy-path tests, generated
+summaries, and optimistic UI as claims, not proof. Treat unverified assumptions
+as blockers or explicit follow-ups.
+
+Keep this section synchronized with `AGENTS.md` whenever either file changes.