anomalyco / anomalyco/opencode

mimo-v2.5 (opencode-go) tool calls fail with "upstream response contained invalid tool calls

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#43,185 2 comments 1 reaction 1 assignee View on GitHub

@fwang is already working on this.

Since Aug 18, 2026.

Dominant language
TypeScript
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Description

Description

When the model is switched to opencode-go/mimo-v2.5 (also reproducible with opencode-go/mimo-v2.5-pro), any
prompt that requires tool calling fails almost immediately with:
stream disconnected before completion: upstream response contained invalid tool calls

Plugins

No response

OpenCode version

2.14.0

Steps to reproduce
  1. Point Codex at the opencodex gateway (http://127.0.0.1:10100/v1).
  2. Select opencode-go/mimo-v2.5 (e.g. via /model).
  3. Ask it to do anything that requires a tool call (run a command, edit a file, use apply_patch, etc.).
  4. Observe the stream disconnects with the error above.
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Operating System

Windows11

Terminal

Windows PowerShell

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

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