diff --git a/loopx/control_plane/collaboration/conversation_binding.ts b/loopx/control_plane/collaboration/conversation_binding.ts
index bd0a0e7f9b..2c7fc465da 100644
--- a/loopx/control_plane/collaboration/conversation_binding.ts
+++ b/loopx/control_plane/collaboration/conversation_binding.ts
@@ -1,6 +1,7 @@
 import type {JsonObject} from "../effect_program.ts";
 import {isDeepStrictEqual} from "node:util";
 import {createHash} from "node:crypto";
+import {BARE_SHA256_PATTERN} from "../content_digest.ts";
 import {EffectRuntimeRequestError} from "../effect_runtime_errors.ts";
 import {requireInteger, requireJsonObject, requireNonEmptyString} from "../runtime_decode.ts";
 import {requireAutomationCadenceEligibility} from "../quota/automation_cadence.ts";
@@ -611,7 +612,7 @@ function planContextRecovery(params: JsonObject, row: JsonObject, current: JsonO
       && Number.isFinite(created) && created >= start && created <= end
       && Number.isSafeInteger(proof.start_step_index) && Number(proof.start_step_index) >= 0
       && Number.isSafeInteger(proof.total_steps) && Number(proof.total_steps) > Number(proof.start_step_index) + 1
-      && [proof.input_sha256, proof.answer_sha256].every(value => typeof value === "string" && /^[a-f0-9]{64}$/.test(value))
+      && [proof.input_sha256, proof.answer_sha256].every(value => typeof value === "string" && BARE_SHA256_PATTERN.test(value))
       && response?.schema_version === "loopx_chat_agent_response_v0"
       && typeof response.message === "string" && response.message.trim().length > 0
       && (adopted === null || adopted.turn_id === failed.turn_id
diff --git a/tests/control_plane_ts/content_digest_single_owner.test.ts b/tests/control_plane_ts/content_digest_single_owner.test.ts
index 7fdd69e9ae..90b2d1c931 100644
--- a/tests/control_plane_ts/content_digest_single_owner.test.ts
+++ b/tests/control_plane_ts/content_digest_single_owner.test.ts
@@ -108,6 +108,7 @@ const CANONICAL_CONSUMERS = [
   "control_plane/capabilities/trajectory_input_usage.ts",
   "control_plane/capabilities/trajectory_tool_context.ts",
   "control_plane/collaboration/chat_mode.ts",
+  "control_plane/collaboration/conversation_binding.ts",
   "control_plane/collaboration/delegation.ts",
   "control_plane/collaboration/delegation_result_use.ts",
   "control_plane/collaboration/goal_instance_lifecycle.ts",
diff --git a/tests/control_plane_ts/conversation_binding.test.ts b/tests/control_plane_ts/conversation_binding.test.ts
index 2117ddd91d..ad25a868b2 100644
--- a/tests/control_plane_ts/conversation_binding.test.ts
+++ b/tests/control_plane_ts/conversation_binding.test.ts
@@ -45,6 +45,16 @@ test("native terminal recovery adopts a result without Turn admission or lost fa
   assert.equal(plan.operation, "adopt_native_result");
   assert.equal(plan.recovery_eligible, true);
   assert.equal(plan.client_turn_id, undefined);
+  for (const field of ["input_sha256", "answer_sha256"]) {
+    for (const invalid of [null, false, 1, [], {}, "", "1".repeat(63), "1".repeat(65),
+      "A".repeat(64), `sha256:${"1".repeat(64)}`]) {
+      assert.equal(planBoundConversationRequest({...packet, context_recovery: {...packet.context_recovery,
+        native_observation: {...proof, [field]: invalid}}}).recovery_eligible, false,
+      `${field} must reject ${JSON.stringify(invalid)}`);
+    }
+    assert.equal(planBoundConversationRequest({...packet, context_recovery: {...packet.context_recovery,
+      native_observation: {...proof, [field]: "abcdef0123456789".repeat(4)}}}).recovery_eligible, true);
+  }
   for (const change of [{source_verified: false}, {stop_observed: true}, {steering_observed: true},
     {attachments_present: true}, {native_observation: {...proof, thread_id: "other"}},
     {native_observation: {...proof, request_ref: "a".repeat(24)}},