fix: truncate MCP tool names exceeding 64 characters#15595
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Br1an67 wants to merge 1 commit intoanomalyco:devfrom
Open
fix: truncate MCP tool names exceeding 64 characters#15595Br1an67 wants to merge 1 commit intoanomalyco:devfrom
Br1an67 wants to merge 1 commit intoanomalyco:devfrom
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The combined MCP server name + tool name can exceed the 64-character limit imposed by LLM APIs (e.g. OpenAI), causing silent failures. Truncate to 64 characters and log a warning when this occurs.
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Issue for this PR
Closes #3523
Type of change
What does this PR do?
MCP tool names are generated by concatenating the MCP server name and tool name (
{server}_{tool}). When this combined name exceeds 64 characters, the OpenAI API rejects it and OpenCode silently stops processing requests.The fix truncates the combined tool name to 64 characters and logs a warning when truncation occurs. This matches what
mcphub.nvimdoes (referenced in the issue).Changed
packages/opencode/src/mcp/index.ts— the tool registration loop now checks length and truncates with a log warning.How did you verify your code works?
Verified the logic by reviewing the code path. The change is a simple conditional truncation on the name string before using it as the tool registry key.
Screenshots / recordings
N/A — no UI change.
Checklist