Analyzed GitHub issue and session data
Public
Analyzed GitHub issue and session data
Agent
Pi
Model
Claude Opus 4.5 (latest)
Started
Jan 17, 7:14 PM
Messages90
Downloads0
Fetched raw gist content.
SetupReviewed relevant code files.
UnderstandProvided detailed analysis of message transformations.
Build
Analyze GitHub issue(s): https://gist.github.com/joshp123/d21219179f76cb7a279a276043e739aa corresponding session .jsonl file is here https://gist.githubusercontent.com/joshp123/d21219179f76cb7a279a276043e739aa/raw/d0f0c93c3a98624705fe8d0750977ce015069029/2026-01-17T16-42-08-945Z_b0026b27-4539-4693-a14b-98eeedbca3fd-redacted.jsonl, dontread it in full, as it will blow up your context window.
For each issue:
Read the issue in full, including all comments and linked issues/PRs.
For bugs:
For feature requests:
Do NOT implement unless explicitly asked. Analyze and propose only.
Let me fetch the raw gist content directly:
Now let me read the relevant code files to analyze the root cause:
Let me check the session log structure briefly to understand what happened:
Let me check line 194 to confirm the flow:
When a Codex session has an assistant message with stopReason: "error", subsequent resume attempts fail with: No tool call found for function call output with call_id call_KXHLl4OkJLqXnzhwMKjeCdHX
The bug is a mismatch between two code paths:
openai-codex-responses.ts:343 - convertAssistantMessage() correctly skips tool calls when stopReason === "error":
} else if (block.type === "toolCall" && msg.stopReason !== "error") {transform-messages.ts:91 - transformMessages() does NOT check stopReason when tracking tool calls for synthetic result generation:
const toolCalls = assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[];stopReason: "error" containing a tool calltransformMessages() sees the tool call, tracks it as "pending"convertMessages():
convertAssistantMessage() SKIPS the tool call (because stopReason === "error")convertToolResult() EMITS function_call_output for the synthetic resultfunction_call_output with no matching function_call → rejectionSingle change in packages/ai/src/providers/transform-messages.ts at line ~91:
// Before:const toolCalls = assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[];
// After:const toolCalls = assistantMsg.stopReason === "error" ? [] : (assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[]);transformMessages() is used by all providers, not just CodexThe issue's LLM suggested also adding a guard in convertMessages() to track emitted call IDs. This would work but is:
packages/ai/src/providers/transform-messages.ts (1 change)ok, pleas emodify
Now let me update the changelog:
Done. Changes made:
packages/ai/src/providers/transform-messages.ts
stopReason === "error" when tracking tool calls from assistant messagespackages/ai/CHANGELOG.md
[Unreleased]commit and push
Committed and pushed. Issue #812 will be automatically closed when the commit lands.
hm, are you sure this doesn't fuck with anything else? i wonder about the fact that providers have additional unfuckering. shouldn't all the unfuckering be contained in transform-messages.ts? analyze the funcukering in all providers and give me a summary of what each provider does on top of transform-messages.ts, whether we can remove some of the provider specific unfuckering, etc.
Let me analyze all providers' message conversion logic:
Now I have a complete picture. Here's the analysis:
transformMessages())transformMessages() does centrally:anthropic.ts)| Transformation | Can Centralize? |
|---|---|
| Empty text/thinking block filtering (whitespace check) | YES |
| Unsigned thinking → plain text (no signature = API rejection) | NO (signature format is Anthropic-specific) |
Tool call ID sanitization [^a-zA-Z0-9_-] → _ | Already in transformMessages() for Anthropic targets |
| Consecutive toolResult merging into single user message | Could, but z.ai specific |
| Cache control on last user message | NO (Anthropic-specific) |
openai-completions.ts)| Transformation | Can Centralize? |
|---|---|
| Empty text/thinking block filtering | YES |
| Empty assistant message skip (checks content+tool_calls) | Already in transformMessages() |
| Mistral tool ID: exactly 9 alphanumeric chars | NO (Mistral-specific quirk) |
| Thinking blocks → text or signature field (llama.cpp) | NO (compat-specific) |
| OpenRouter Anthropic cache_control | NO (OpenRouter+Anthropic specific) |
openai-responses.ts)| Transformation | Can Centralize? |
|---|---|
Skip thinking/toolCall when stopReason === "error" | See analysis below |
| Message ID hashing for IDs > 64 chars | NO (OpenAI Responses specific) |
Tool call ID format call_id|id splitting | NO (OpenAI Responses specific) |
openai-codex-responses.ts)| Transformation | Can Centralize? |
|---|---|
Skip thinking/toolCall when stopReason === "error" | See analysis below |
Tool call ID format call_id|id splitting | NO (Codex specific) |
google-shared.ts)| Transformation | Can Centralize? |
|---|---|
| Empty text/thinking block filtering | YES |
| Thinking signature validation (base64, same provider) | NO (Google signature format) |
| Unsigned Gemini 3 tool calls → descriptive text | NO (Gemini 3 specific) |
Tool result format {output} vs {error} | NO (Gemini specific) |
| Function responses merging (Cloud Code Assist) | Could, but provider specific |
amazon-bedrock.ts)| Transformation | Can Centralize? |
|---|---|
| Empty assistant message skip | Already in transformMessages() |
| Empty text/thinking block filtering | YES |
| Thinking signature only for Anthropic Claude | NO (model-specific) |
| Tool call ID sanitization | Could reuse Anthropic's |
| Consecutive toolResult merging | Could, similar to Anthropic |
stopReason === "error" SituationCurrent state after my fix:
| Provider | Has stopReason !== "error" check for toolCall? | Has check for thinking? |
|---|---|---|
| OpenAI Responses | YES | YES |
| OpenAI Codex | YES | YES |
| Anthropic | NO | NO |
| OpenAI Completions | NO | NO |
| NO | NO | |
| Bedrock | NO | NO |
Why this is correct:
OpenAI Responses/Codex require matching function_call → function_call_output pairs. They explicitly drop tool calls from errored messages, so we must not create synthetic results for them. My fix + their check = correct.
Other providers (Anthropic, OpenAI Completions, Google, Bedrock) don't have this requirement. They include tool calls from errored messages, and if there's a result (synthetic or real), it matches. No orphan problem.
The fix is correct and sufficient. The provider-specific checks in Responses/Codex are defense-in-depth.
Almost every provider filters empty text/thinking blocks. Add to transformMessages():
// In the assistant message content transformationconst transformedContent = assistantMsg.content.flatMap((block) => { // Skip empty text blocks if (block.type === "text" && (!block.text || block.text.trim() === "")) return []; // Skip empty thinking blocks if (block.type === "thinking" && (!block.thinking || block.thinking.trim() === "")) return []; // ... rest of transformation});The stopReason !== "error" checks in Responses/Codex serve as defense-in-depth. They're now somewhat redundant for synthetic results (central fix handles that), but they still protect against:
Anthropic, Bedrock, and Google all merge consecutive toolResult messages. Could be done centrally, but low priority since it works.
Bottom line: The fix is correct. The provider-specific "unfuckering" serves different purposes and mostly can't be centralized due to provider quirks. The one big win would be centralizing empty block filtering.
} else if (block.type === "toolCall" && msg.stopReason !== "error") {const toolCalls = assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[];// Before:const toolCalls = assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[];
// After:const toolCalls = assistantMsg.stopReason === "error" ? [] : (assistantMsg.content.filter((b) => b.type === "toolCall") as ToolCall[]);// In the assistant message content transformationconst transformedContent = assistantMsg.content.flatMap((block) => { // Skip empty text blocks if (block.type === "text" && (!block.text || block.text.trim() === "")) return []; // Skip empty thinking blocks if (block.type === "thinking" && (!block.thinking || block.thinking.trim() === "")) return []; // ... rest of transformation});