invalid_request_error: Invalid 'input[15].arguments': string too long

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• #10506

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have the same issue with latest 0.107.0 cli mode (not exec), I see "Invalid 'input[119].arguments': string too long. Expected a string with maximum length 1048576, but got a string with length
2261315 instead.

happened with spark but changing models doesnt fix the session

{ "error": { "message": "Invalid 'input[531].arguments': string too long. Expected a string with maximum length 1048576, but got a string with length 1508785 instead.", "type": "invalid_request_error", "param": "input[531].arguments", "code": "string_above_max_length" } }

{
  "type": "error",
  "error": {
    "type": "invalid_request_error",
    "message": "[StringParam] [input[85].arguments] [string_above_max_length] Invalid 'input[85].arguments': string too long. Expected a string with maximum length 1048576, but
got a string with length 1420421 instead."
  },
  "status": 400
}

Codex Spark. But swapping back to another model with the existing session doesn't resolve the problem.

> codex --version
codex-cli 0.129.0

same issue for me

Any updates on this?

Definitely the same issue. Any solution?

I am also seeing this issue, tried changing the reasoning level since changing the model doesn't seem to work either but the issue is still present.

Additional reproduction from Codex Desktop on macOS:

After the UI displayed “Context automatically compacted”, the session failed with:

[StringParam] [input[413].arguments] [string_above_max_length]
Invalid 'input[413].arguments': string too long.
Expected a string with maximum length 1048576, but got a string with length 1279780 instead.

This occurred in the same thread after automatic context compaction. The error prevents the turn from continuing.

After the UI displayed “Context automatically compacted”, the session failed with:

Already restarted my app nothing change and im up to date with the latest version:
Version 26.707.72221

Proposed fix (not submitted as a PR because external code contributions are invitation-only; see contributing guidelines).

This report is a concrete input[*].arguments reproduction of the older oversized replay payload family reported in #10506, while #13270 captures the function-call-arguments variant.

Patch outline

At the request-history formatting boundary in codex-rs/core/src/client_common.rs:

1. Identify completed FunctionCall items whose arguments string is above a conservative 1,000,000-character limit.
2. Replace only those replayed arguments with a small valid JSON placeholder.
3. Preserve the call_id and matching FunctionCallOutput.
4. Leave unfinished calls and the original in-memory history unchanged.
5. Add a regression test covering the automatic-compaction failure.

The proposed patch is implemented and locally validated on branch agent/oversized-tool-arguments-pr, commit 9a00d3c00c.

Validation:

• cargo test -p codex-core client_common::tests: 7 passed
• git diff --check: passed
• Clippy reaches the changed code but is blocked by the pre-existing clippy::large_enum_variant error in core-plugins/src/manifest.rs.

This avoids blindly truncating active tool calls and prevents a completed historical call from making the next Responses API request invalid.