diff --git a/tests/account_facts_history_currencies_validation.mjs b/tests/account_facts_history_currencies_validation.mjs
index 3f3767fa..c5bee1a9 100644
--- a/tests/account_facts_history_currencies_validation.mjs
+++ b/tests/account_facts_history_currencies_validation.mjs
@@ -94,6 +94,11 @@ console.log('account facts history currency discovery: synthetic qualified linea
 // Exercise the actual Worker wiring: its binding loader must not swallow a KV
 // read failure before the history use case can distinguish it from no binding.
 const { default: worker, __test } = await import('../web/strategy-switch-console/worker.js');
+// Sync producers keep only the HTTP status, so each refusal must also name its
+// code in one bounded log event. Capture the events instead of printing them.
+const rejections=[];
+const realWarn=console.warn;
+console.warn=(event,...rest)=>{ if(event==='account_facts_refused') rejections.push(rest[0]); else realWarn.apply(console,[event,...rest]); };
 let kvFailure=null, missingBinding=false, storedHistory={ok:true,days:[]}, storedStatus=200;
 const workerEnv={
   ACCOUNT_FACTS_READ_MODEL_ENABLED:'true',
@@ -151,4 +156,41 @@ try {
   missingBinding=true;
   assert.equal((await requestHistory(legacyUrl)).status,200,'a successful missing binding read keeps its legacy empty state');
 } finally {globalThis.fetch=originalFetch;}
+// One event per refusal, the code identical to the one the client receives, and no
+// field beyond the fixed endpoint, the status and the classified code.
+assert.ok(rejections.length>=3,'every rejected account-facts read above is observable');
+assert.deepEqual(rejections.at(-1),{endpoint:'read',http_status:409,error_category:'account_facts_stored_invalid'},
+  'the logged code is exactly the code the producer receives');
+for(const event of rejections){
+  assert.deepEqual(Object.keys(event).sort(),['endpoint','error_category','http_status'],'the event carries no other field');
+  assert.equal(event.endpoint,'read','reads keep the default endpoint literal');
+  assert.match(event.error_category,/^[a-z][a-z0-9_]{2,63}$/);
+  assert.ok(Number.isInteger(event.http_status)&&event.http_status>=400&&event.http_status<=599);
+}
+// A free-form failure keeps its previous response body but is classified, never copied.
+const unclassified=await __test.accountFactsErrorResponse(new Error('net_assets 98765.432101 rejected'));
+assert.equal(unclassified.status,400,'an unclassified failure stays a 400');
+assert.equal((await unclassified.json()).error,'net_assets 98765.432101 rejected','the response is unchanged');
+assert.equal(rejections.at(-1).error_category,'unknown','free-form text is classified, never copied');
+const syncRefusal=await __test.accountFactsErrorResponse(
+  Object.assign(new Error('period_return_conflict'),{status:409}),'period_return_sync');
+assert.equal(syncRefusal.status,409);
+assert.equal((await syncRefusal.json()).error,'period_return_conflict');
+assert.deepEqual(rejections.at(-1),{endpoint:'period_return_sync',http_status:409,error_category:'period_return_conflict'},
+  'a sync refusal names the endpoint the producer posted to');
+// Both sync routes live in application/account_facts/sync.js and call their injected
+// error mapper with no endpoint, so the worker injection site must pick the label from
+// the route; otherwise a refused current snapshot would be logged as a history append.
+for(const [path,endpoint] of [['/api/account-facts/sync','current_sync'],['/api/account-facts/history/sync','history_sync']]){
+  const refused=await worker.fetch(new Request(`https://switch.example${path}`,{
+    method:'POST',headers:{'Content-Type':'application/json'},body:'{}',
+  }),workerEnv);
+  assert.equal(refused.status,500,'this synthetic env configures no sync token');
+  assert.deepEqual(await refused.json(),{ok:false,error:'account_facts_sync_token_not_configured'});
+  assert.deepEqual(rejections.at(-1),
+    {endpoint,http_status:500,error_category:'account_facts_sync_token_not_configured'},
+    `${path} is attributed to its own sync endpoint, not to a read`);
+}
+assert.ok(!JSON.stringify(rejections).includes('98765'),'no payload value reaches the log stream');
+console.warn=realWarn;
 console.log('account facts history Worker wiring: synthetic KV/DO failures and empty states passed');
diff --git a/web/strategy-switch-console/worker.js b/web/strategy-switch-console/worker.js
index 56f7fa17..c41c6f01 100644
--- a/web/strategy-switch-console/worker.js
+++ b/web/strategy-switch-console/worker.js
@@ -11530,14 +11530,22 @@ function accountFactsDisabledResponse() {
   return json({ ok: false, error: "account_facts_disabled" }, 404);
 }
 
-function accountFactsErrorResponse(error) {
-  if (error instanceof AccountFactsError) {
-    return json({ ok: false, error: error.code }, error.status || 400);
-  }
-  if (error instanceof HttpError) {
-    return json({ ok: false, error: error.message }, error.status || 400);
-  }
-  return json({ ok: false, error: error?.message || "invalid_account_facts_history" }, error?.status || 400);
+// Sync producers keep only the HTTP status, so a refused push is undiagnosable
+// from their logs. Publish the refusal code, tagged with a fixed endpoint literal
+// from the caller; free-form exception text is classified to "unknown" so payload
+// content, identities and credentials cannot enter the log stream. The response
+// body and status are exactly what this helper already returned.
+function accountFactsErrorResponse(error, endpoint = "read") {
+  const code = error instanceof AccountFactsError ? error.code
+    : error instanceof HttpError ? error.message
+    : error?.message || "invalid_account_facts_history";
+  const status = error?.status || 400;
+  console.warn("account_facts_refused", {
+    endpoint,
+    http_status: status,
+    error_category: typeof code === "string" && /^[a-z][a-z0-9_]{2,63}$/.test(code) ? code : "unknown",
+  });
+  return json({ ok: false, error: code }, status);
 }
 
 function requireCycleHealthProvisionToken(request, env) {
@@ -11773,7 +11781,7 @@ async function syncAccountExternalFlowResponse(request, env) {
       record_count: new Set(flow.windows.flatMap(w => w.records.map(r => r.source_ref))).size });
   } catch (error) {
     if (error instanceof AccountFactsError || error instanceof HttpError || error?.code?.startsWith("external_flow")
-        || error?.code === "invalid_external_flow") return accountFactsErrorResponse(error);
+        || error?.code === "invalid_external_flow") return accountFactsErrorResponse(error, "external_flow_sync");
     return json({ ok: false, error: "account_external_flow_unavailable" }, 503);
   }
 }
@@ -11798,7 +11806,7 @@ async function syncAccountExecutionsResponse(request, env) {
       account_key: binding.account_key, period: payload.period, record_count: payload.records.length });
   } catch (error) {
     if (error instanceof AccountFactsError || error instanceof HttpError || error?.code?.startsWith("execution_")
-        || error?.code === "invalid_broker_executions") return accountFactsErrorResponse(error);
+        || error?.code === "invalid_broker_executions") return accountFactsErrorResponse(error, "executions_sync");
     return json({ ok: false, error: "account_executions_unavailable" }, 503);
   }
 }
@@ -11822,7 +11830,7 @@ async function syncAccountPeriodReturnResponse(request, env) {
     return json({ ok: true, stored: true, unchanged: stored.unchanged === true, account_key: binding.account_key,
       period: payload.period, currency: payload.currency, method: payload.method });
   } catch (error) {
-    if (error instanceof AccountFactsError || error instanceof HttpError) return accountFactsErrorResponse(error);
+    if (error instanceof AccountFactsError || error instanceof HttpError) return accountFactsErrorResponse(error, "period_return_sync");
     return json({ ok: false, error: "account_period_return_unavailable" }, 503);
   }
 }
@@ -11837,7 +11845,8 @@ async function syncAccountFactsResponse(request, env, options) {
     runtimeInstanceCommand,
     readBoundedJson,
     requireDedicatedAccountFactsSyncToken,
-    accountFactsErrorResponse,
+    accountFactsErrorResponse: (error) => accountFactsErrorResponse(
+      error, options?.historical ? "history_sync" : "current_sync"),
   }, options);
 }
 
@@ -17732,6 +17741,7 @@ export const __test = {
   resolveTrustedAccountFactsBinding,
   decideAccountFactsPut,
   accountFactsOptionMatchesBinding,
+  accountFactsErrorResponse,
   canonicalizeAccountFactsHistory,
   ux1JobUnknownAfterMs: UX1_JOB_UNKNOWN_AFTER_MS,
   ux1CalculatorDeadlineMs: UX1_CALCULATOR_DEADLINE_MS,