LibreChat/packages
Danny Avila 275af48592
🎯 fix: MCP Tool Misclassification from Action Delimiter Collision (#12512)
* fix: prevent MCP tools with `_action` in name from being misclassified as OpenAPI action tools

Add `isActionTool()` helper that checks for the `_action_` delimiter
while guarding against cross-delimiter collision with `_mcp_`. Replace
all `includes(actionDelimiter)` classification checks with the new
helper across backend and frontend.

* test: add coverage for MCP/action cross-delimiter collision

Verify that `isActionTool` correctly rejects MCP tool names containing
`_action` and that `loadAgentTools` does not filter them based on
`actionsEnabled`. Add ToolIcon and definitions test cases.

* fix: simplify isActionTool to handle all MCP name patterns

- Use `!toolName.includes('_mcp_')` instead of checking only after the
  first `_action_` occurrence, which missed MCP tools with `_action_` in
  the middle of their name (e.g. `get_action_data_mcp_myserver`).
- Reference `Constants.mcp_delimiter` value via a local const to avoid
  circular import from config.ts, with a comment explaining why.
- Remove dead `actionDelimiter` import from definitions.ts.
- Replace double-filter with single-pass partition in loadToolsForExecution.
- Add test for mid-name `_action_` collision case.

* fix: narrow MCP exclusion to delimiter position in isActionTool

Only reject when `_mcp_` appears after `_action_` (the MCP suffix
position). `_mcp_` before `_action_` is part of the operationId and
is valid — e.g. `sync_mcp_state_action_api---example---com` is a
legitimate action tool whose operationId happens to contain `_mcp_`.

* fix: document positional _mcp_ guard and known RFC-invalid domain limitation

Expand JSDoc on isActionTool to explain the action/MCP format
disambiguation and the theoretical false negative for non-RFC-compliant
domains containing `_mcp_`. Add test documenting this known edge case.
2026-04-01 22:36:21 -04:00
..
api 🎯 fix: MCP Tool Misclassification from Action Delimiter Collision (#12512) 2026-04-01 22:36:21 -04:00
client 📦 chore: bump dependabot packages (#12487) 2026-03-31 13:36:20 -04:00
data-provider 🎯 fix: MCP Tool Misclassification from Action Delimiter Collision (#12512) 2026-04-01 22:36:21 -04:00
data-schemas 🛡️ refactor: Self-Healing Tenant Isolation Update Guard (#12506) 2026-04-01 19:07:52 -04:00