fix(devin): carry reasoning signatures across turns

scripts/test-layout/layout.json

@@ -920,6 +920,8 @@
     "devin-provider-merge-migration.test.ts": "providers",
     "devin-stated-reset-hardening.test.ts": "providers",
     "devin-stated-reset-retry.test.ts": "providers",
+    "devin-anthropic-signature-fallback.test.ts": "providers",
+    "devin-reasoning-continuation.test.ts": "providers",
     "devin-stream-deadline.test.ts": "providers",
     "digitalocean-scaleway-provider.test.ts": "providers",
     "docs-429-failover-claims.test.ts": "ci-workflows",

src/adapters/devin.ts

@@ -15,7 +15,7 @@ import { getCachedCatalog, type CacheEntry } from "./devin/cloud-direct/catalog"
 import { collapseDevinModelUid } from "./devin/live-models";
 import { buildNonOpenAIToolCatalogNudgeForTools } from "./tool-catalog-nudge";
 import { DEVIN_DEFAULT_API_SERVER, resolveDevinApiServer } from "../oauth/devin";
-import { isProviderIssuedThinkingSignature } from "../responses/reasoning-envelope";
+import { devinAssistantReasoning, encodeDevinSignature, hasAnthropicSignature } from "./devin/reasoning-signature";
 import { SendBudgetExhaustedError } from "../lib/upstream-retry";
 
 /**
@@ -364,45 +364,16 @@ function assistantText(message: OcxAssistantMessage): string {
     // Thinking stays out of the replayed TEXT: folding chain-of-thought into
     // assistant text sends it back as visible prior output, which the model
     // then treats as something it said to the user. It is replayed in its own
-    // field instead — see assistantThinking below.
+    // field instead — see devinAssistantReasoning.
     .map((part) => (part.type === "text" ? part.text : ""))
     .filter(Boolean)
     .join("\n");
 }
 
-/**
- * The assistant turn's own reasoning, for replay in ChatMessagePrompt #11.
- *
- * This adapter previously asserted that Cognition has no reasoning-replay
- * field and dropped the thinking outright, so a reasoning model restarted its
- * chain on every turn of a tool loop. The field exists: two independent
- * clients of the same service write #11 thinking with #12 signature and #18
- * signature_type on the assistant prompt.
- *
- * Field #12 attests the exact text at #11, and the wire has room for one pair.
- * Every block that carries text is replayed, so the chain stays intact; the
- * signature rides along only when the text being replayed IS the text it
- * attests, which is exactly the single-block case. Several independently signed
- * blocks send an unsigned prompt rather than pairing one block's attestation
- * with another block's words. A signature-only block attests encrypted thinking
- * that is not being replayed at all, so it is not one of these blocks and
- * cannot contribute the pair.
- */
-function assistantThinking(
-  message: OcxAssistantMessage,
-): { thinking?: string; signature?: string } {
-  const blocks = message.content.filter(
-    (part): part is Extract<typeof part, { type: "thinking" }> => part.type === "thinking",
-  ).filter(part => Boolean(part.thinking));
-  if (blocks.length === 0) return {};
-  const signature = blocks.length === 1 ? blocks[0]!.signature : undefined;
-  return {
-    thinking: blocks.map(part => part.thinking).join("\n"),
-    ...(isProviderIssuedThinkingSignature(signature) ? { signature } : {}),
-  };
-}
-
-export function mapOcxMessagesToDevin(parsed: OcxParsedRequest): ChatHistoryItem[] {
+export function mapOcxMessagesToDevin(
+  parsed: OcxParsedRequest,
+  options: { withholdAnthropicSignatures?: boolean } = {},
+): ChatHistoryItem[] {
   const items: ChatHistoryItem[] = [];
   // Cognition is not an OpenAI host, and this adapter does advertise a real
   // client tool catalog (proto #10 via `mapOcxToolsToDevin`), so the same
@@ -421,13 +392,17 @@ export function mapOcxMessagesToDevin(parsed: OcxParsedRequest): ChatHistoryItem
   if (system) items.push({ role: "system", content: system });
 
   for (const message of parsed.context.messages) {
-    const mapped = mapOneMessage(message);
+    const mapped = mapOneMessage(message, parsed.modelId, options);
     if (mapped) items.push(mapped);
   }
   return items;
 }
 
-function mapOneMessage(message: OcxMessage): ChatHistoryItem | undefined {
+function mapOneMessage(
+  message: OcxMessage,
+  modelId: string,
+  options: { withholdAnthropicSignatures?: boolean },
+): ChatHistoryItem | undefined {
   if (message.role === "user" || message.role === "developer") {
     const content = mapOcxContentToWire(message.content);
     // An image with no caption text is a complete user message on its own.
@@ -439,10 +414,10 @@ function mapOneMessage(message: OcxMessage): ChatHistoryItem | undefined {
   if (message.role === "assistant") {
     const toolCalls = assistantToolCalls(message);
     const text = assistantText(message);
-    const reasoning = assistantThinking(message);
+    const reasoning = devinAssistantReasoning(message, modelId, options.withholdAnthropicSignatures === true);
     // A turn that produced only reasoning is still worth replaying: dropping it
     // is what makes the next turn re-derive the same chain.
-    if (!text && toolCalls.length === 0 && !reasoning.thinking) return undefined;
+    if (!text && toolCalls.length === 0 && !reasoning.thinking && !reasoning.signature) return undefined;
     return {
       role: "assistant",
       content: text || "",
@@ -648,12 +623,20 @@ export function createDevinAdapter(
         // An admitted HTTP turn owns globally shared capacity until this call
         // emits. Without an explicit wait allowance, preserve the typed reset
         // delay in generated diagnostic wording and return immediately.
-        for await (const event of streamChatEventsWithResetRetry({
+        const signedMessages = mapOcxMessagesToDevin(parsed);
+        // A Claude signature is replayed because it is what carries the reasoning into this
+        // turn, but Cognition streams Claude's thinking as a summary the signature does not
+        // cover, and some replays are refused with invalid_argument before any output. That
+        // refusal is retried once with the Anthropic signatures withheld and the text kept.
+        const unsignedMessages = hasAnthropicSignature(signedMessages, parsed.modelId)
+          ? mapOcxMessagesToDevin(parsed, { withholdAnthropicSignatures: true })
+          : undefined;
+        const request = (messages: ChatHistoryItem[]) => streamChatEventsWithResetRetry({
           apiKey,
           apiServerUrl: host,
           modelUid,
           catalog,
-          messages: mapOcxMessagesToDevin(parsed),
+          messages,
           tools: mapOcxToolsToDevin(parsed.context.tools),
           cascadeId,
           // Input and output ceilings are separate wire fields. Omitting the
@@ -675,7 +658,22 @@ export function createDevinAdapter(
             onPhysicalSend: incoming.onPhysicalSend,
             onRecoveryWithheld: incoming.onRecoveryWithheld,
           },
-        })) {
+        });
+        async function* withSignatureFallback() {
+          let produced = false;
+          try {
+            for await (const event of request(signedMessages)) {
+              // Only visible output makes a retry unsafe. Live, the refusal often lands after the
+              // model has streamed its reasoning, its signature and a finish frame, and nothing else.
+              produced ||= event.kind === "text" || event.kind === "tool_call_start" || event.kind === "tool_call_args";
+              yield event;
+            }
+          } catch (error) {
+            if (!unsignedMessages || produced || !(error instanceof CloudChatError && error.code === "invalid_argument")) throw error;
+            yield* request(unsignedMessages);
+          }
+        }
+        for await (const event of withSignatureFallback()) {
           if (incoming.abortSignal?.aborted) {
             // Emitting nothing here left the bridge to synthesize adapter_eof.
             // Say what happened instead, the way the other runTurn-only adapter
@@ -696,7 +694,7 @@ export function createDevinAdapter(
           if (event.kind === "reasoning_signature") {
             // Carried back out so the next turn can replay it in the prompt's
             // signature field; an unsigned replay is what the service ignores.
-            emit({ type: "thinking_signature", signature: event.signature });
+            emit({ type: "thinking_signature", signature: encodeDevinSignature(event.signature, event.signatureType) });
             continue;
           }
           if (event.kind === "tool_call_start") {

src/adapters/devin/cloud-direct/chat.ts

@@ -486,7 +486,7 @@ export type CloudChatEvent =
    * turn produced. Without decoding it there is nothing to put in the prompt's
    * #12 on the next turn, so the replay would always be unsigned.
    */
-  | { kind: 'reasoning_signature'; signature: string }
+  | { kind: 'reasoning_signature'; signature: string; signatureType?: string }
   | { kind: 'tool_call_start'; id: string; name: string }
   | {
       kind: 'tool_call_args';
@@ -792,6 +792,10 @@ export function* decodeChatFrame(proto: Buffer): Generator<CloudChatEvent> {
     }
   }
   if (authoritativeUsage) yield authoritativeUsage;
+  let signatureType: string | undefined;
+  for (const f of iterFields(proto)) {
+    if (f.num === 21 && f.wire === 2 && Buffer.isBuffer(f.value)) signatureType = (f.value as Buffer).toString('utf8') || undefined;
+  }
   for (const f of iterFields(proto)) {
     if (f.num === 3 && f.wire === 2 && Buffer.isBuffer(f.value)) {
       // Visible delta_text — what the user should SEE in the chat.
@@ -817,7 +821,8 @@ export function* decodeChatFrame(proto: Buffer): Generator<CloudChatEvent> {
       if (s) yield { kind: 'reasoning', text: s };
     } else if (f.num === 10 && f.wire === 2 && Buffer.isBuffer(f.value)) {
       const s = (f.value as Buffer).toString('utf8');
-      if (s) yield { kind: 'reasoning_signature', signature: s };
+      // #21 delta_signature_type arrives in the same frame; the prompt replays it as #18.
+      if (s) yield { kind: 'reasoning_signature', signature: s, ...(signatureType ? { signatureType } : {}) };
     } else if (f.num === 6 && f.wire === 2 && Buffer.isBuffer(f.value)) {
       let id: string | undefined;
       let name: string | undefined;

src/adapters/devin/reasoning-signature.ts

@@ -0,0 +1,94 @@
+/**
+ * Devin reasoning signatures across turns.
+ *
+ * GetChatMessage returns the turn's reasoning attestation as `delta_signature`
+ * (#10) together with `delta_signature_type` (#21) in the same frame, and the
+ * native client replays both on the assistant prompt as #12 and #18. Measured
+ * live on swe-2-high the pair arrives AFTER the visible answer (reasoning, text,
+ * then signature), so the Responses layer stores it as its own signature-only
+ * reasoning item behind the thinking-text item. GPT and Gemini rows stream no
+ * thinking text at all, only the signature.
+ *
+ * The type is carried inside the stored signature because the reasoning
+ * envelope that round-trips through the client keeps a single signature string.
+ * A signature stored before this prefix existed replays without a type.
+ */
+import type { OcxAssistantMessage } from "../../types";
+import { isProviderIssuedThinkingSignature } from "../../responses/reasoning-envelope";
+
+const TYPED_SIGNATURE_PREFIX = "devin-sig1:";
+
+export function encodeDevinSignature(signature: string, signatureType: string | undefined): string {
+  return signatureType && !signatureType.includes(":")
+    ? `${TYPED_SIGNATURE_PREFIX}${signatureType}:${signature}`
+    : signature;
+}
+
+export function decodeDevinSignature(stored: string): { signature: string; signatureType?: string } {
+  if (!stored.startsWith(TYPED_SIGNATURE_PREFIX)) return { signature: stored };
+  const rest = stored.slice(TYPED_SIGNATURE_PREFIX.length);
+  const colon = rest.indexOf(":");
+  if (colon <= 0) return { signature: stored };
+  return { signature: rest.slice(colon + 1), signatureType: rest.slice(0, colon) };
+}
+
+/**
+ * The assistant turn's reasoning for ChatMessagePrompt #11/#12/#18.
+ *
+ * All of the turn's thinking text is replayed. A signature rides along only
+ * when it covers exactly that text:
+ * - one thinking block carrying its own issued signature (a stray
+ *   signature-only block does not displace it);
+ * - at most one unsigned thinking block plus exactly one signature-only block,
+ *   which is how a single Devin turn arrives once its late #10 frame has been
+ *   split into its own reasoning item. With no thinking block at all this is a
+ *   GPT or Gemini row, where the signature is the only reasoning there is.
+ * Any other mix (two signed blocks, a signed block beside unsigned text) has no
+ * single attestation for the joined text, so the turn is replayed unsigned.
+ *
+ * `withholdAnthropic` drops an Anthropic signature and keeps the text: the
+ * fallback for a Claude turn Cognition refused (see hasAnthropicSignature).
+ */
+export function devinAssistantReasoning(
+  message: OcxAssistantMessage,
+  modelId = "",
+  withholdAnthropic = false,
+): { thinking?: string; signature?: string; signature_type?: string } {
+  const blocks = message.content.filter(
+    (part): part is Extract<typeof part, { type: "thinking" }> => part.type === "thinking",
+  );
+  const textBlocks = blocks.filter(part => Boolean(part.thinking));
+  const signatureOnly = blocks.filter(part => !part.thinking && isProviderIssuedThinkingSignature(part.signature));
+  const text = textBlocks.map(part => part.thinking).join("\n");
+  let stored: string | undefined;
+  if (textBlocks.length === 1 && isProviderIssuedThinkingSignature(textBlocks[0]!.signature)) {
+    stored = textBlocks[0]!.signature;
+  } else if (textBlocks.length <= 1 && signatureOnly.length === 1) {
+    stored = signatureOnly[0]!.signature;
+  }
+  let decoded = stored ? decodeDevinSignature(stored) : undefined;
+  if (decoded && withholdAnthropic && signatureTypeFor(decoded, modelId) === "anthropic") decoded = undefined;
+  return {
+    ...(text ? { thinking: text } : {}),
+    ...(decoded ? { signature: decoded.signature } : {}),
+    ...(decoded?.signatureType ? { signature_type: decoded.signatureType } : {}),
+  };
+}
+
+/** A stored signature from before its type was recorded falls back to the model being called. */
+function signatureTypeFor(decoded: { signatureType?: string }, modelId: string): string | undefined {
+  return decoded.signatureType ?? (/claude/i.test(modelId) ? "anthropic" : undefined);
+}
+
+/**
+ * True when the mapped history replays a Claude signature. Cognition streams
+ * Claude's thinking as a summary while the signature covers the original, so
+ * the pair can fail validation: live on claude-opus-5-5 a signed replay of a
+ * visible-thinking turn was refused with `invalid_argument` in 5 of 6 tries and
+ * a text-only one in none, while a signed replay that is accepted is what lets
+ * the model recall its earlier reasoning. The adapter therefore sends the
+ * signature and retries a refusal once without it.
+ */
+export function hasAnthropicSignature(items: ReadonlyArray<{ signature?: string; signature_type?: string }>, modelId: string): boolean {
+  return items.some(item => Boolean(item.signature) && signatureTypeFor({ signatureType: item.signature_type }, modelId) === "anthropic");
+}