[Bug]: Routed exec_command call carrying {"input": ...} is not repaired, so the client rejects every call with missing field cmd #5370

Client or integration

Codex App

Area

Tools / MCP / web search

Summary

A routed model can emit a call named exec_command whose arguments are {"input": "<shell command>"}. By the time it reaches the client the call is still named exec_command, so the alias in normalizeDeclaredToolName did not apply, which is the documented behaviour when the catalog declares a bare bridge name. Nothing repairs the argument key either, so the client rejects it with:

failed to parse function arguments: missing field \`cmd\` at line 1 column 127

and the command never runs.

What I expected: since the request declares exec_command with cmd required, a body that carries a single string input should be repaired to {"cmd": ...}, the same way sibling shapes already are:

• unwrapFreeformToolInput unwraps {"input": ...} for the freeform exec and apply_patch bodies, with fallback keys including cmd and command.
• compileCodeModeHelperInput remaps command to cmd for the shell_command helper.
• normalizeDeclaredToolName maps nested helper names back to exec when the catalog declares code mode.

Reproduction

1. Route a Codex App session to opencode-go/deepseek-v4.1-flash through the proxy, with openai_base_url pointed at the local proxy.
2. Ask for work that needs shell commands.
3. The model emits exec_command with {"input": "cd <dir> && sed -n '1,120p' file.ts"}.
4. The client answers with the error above and the call does not run.

Observed in one session, from the local rollout file:

• 138 calls named exec_command with {"input": ...}, all 138 rejected with the message above.
• The same model ran 215 code-mode exec calls correctly in the same session, so routing and the tool pipeline work.
• The failures start exactly when the thread switches from another routed model to this one, and one of them carries code-mode JavaScript (const { exec_command } = tools; ...) inside that input. It reads like the model kept the nested helper's name and borrowed the parent exec tool's input key.
• It never adapted: 138 identical rejections, no change of shape.

Version

2.59.0

Operating system

macOS (darwin arm64)

Provider and model

opencode-go/deepseek-v4.1-flash

Logs or error output

failed to parse function arguments: missing field \`cmd\` at line 1 column 127
failed to parse function arguments: missing field \`cmd\` at line 1 column 3677

Screenshots and supporting files

None.

Redacted configuration

{
  "openai_base_url": "http://127.0.0.1:10100/backend-api/codex"
}

The affected turn's catalog declared the code-mode exec tool next to a bare shell bridge name.

Checks

• I searched existing issues and documentation.
• I removed secrets, tokens, account details, request credentials, and personal data.