🧠 refactor: Memoize MCP Permission Checks Per Request

[danny-avila]

Summary

I added request-scoped memoization for MCP server use permission checks so multi-agent requests and repeated MCP tool execution reuse the same role permission lookup.

• Added checkAccessWithRequestCache to cache simple role permission checks by permission type, permissions, user ID, and role on the Express request.
• Added a small MCP permission context interface so MCP tool construction receives canUseServers(user) instead of raw Express request state.
• Routed MCP server use checks through the cached helper while preserving fail-closed behavior when the user or role is missing.
• Passed the MCP permission context through load-time filtering, agent create/update/duplicate/revert filtering, and MCP tool construction so runtime calls reuse the same request cache.
• Added unit coverage for cached access checks and repeated MCP tool invocations within one request.

Change Type

• Bug fix (non-breaking change which fixes an issue)

Testing

• cd packages/api && npx jest src/middleware/access.spec.ts --runInBand --coverage=false
• npm run build:api
• cd api && npx jest server/services/MCP.spec.js --runInBand --coverage=false
• cd api && npx jest server/services/__tests__/ToolService.spec.js server/controllers/agents/filterAuthorizedTools.spec.js --runInBand --coverage=false
• cd api && npx jest server/services/MCP.spec.js server/services/__tests__/ToolService.spec.js server/controllers/agents/filterAuthorizedTools.spec.js --runInBand --coverage=false
• npx eslint packages/api/src/middleware/access.ts packages/api/src/middleware/access.spec.ts api/server/services/MCP.js api/server/services/MCP.spec.js api/app/clients/tools/util/handleTools.js api/server/services/ToolService.js api/server/controllers/agents/v1.js
• npx eslint api/server/services/MCP.js api/server/services/MCP.spec.js api/app/clients/tools/util/handleTools.js api/server/services/ToolService.js api/server/services/__tests__/ToolService.spec.js api/server/controllers/agents/v1.js api/server/controllers/agents/filterAuthorizedTools.spec.js

Test Configuration:

• Base branch: dev
• Workspace: /Users/danny/.codex/worktrees/9dfc/LibreChat

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes

[Copilot]

Pull request overview

Adds request-scoped memoization for MCP server USE permission checks so multi-agent flows and repeated MCP tool invocations within a single request do not re-fetch the user's role. A new checkAccessWithRequestCache helper stores a Promise<boolean> keyed by permission type/permissions/user id/role on a non-enumerable property of the Express request, and userCanUseMCPServers is routed through it. The req object is now threaded through MCP load-time filtering, agent CRUD MCP filtering, and the MCP tool construction/invocation path.

Changes:

• New checkAccessWithRequestCache helper in packages/api/src/middleware/access.ts with unit tests covering memoization, in-flight sharing, request isolation, and permission-key separation.
• userCanUseMCPServers accepts and forwards req; threaded through createMCPTools/createMCPTool/createToolInstance and through agent CRUD (filterAuthorizedTools, update/duplicate/revert handlers) and loadTools/loadToolDefinitionsWrapper/loadAgentTools.
• New MCP service test asserts a single getRoleByName call across two MCP tool invocations sharing the same request.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/api/src/middleware/access.ts	Adds CheckAccessParams type and checkAccessWithRequestCache with a per-request promise cache.
packages/api/src/middleware/access.spec.ts	New tests for memoization, in-flight sharing, request isolation, and per-permission cache keys.
api/server/services/MCP.js	Switches userCanUseMCPServers to the cached helper and plumbs req through MCP tool construction/invocation.
api/server/services/MCP.spec.js	Adds test verifying cached role lookup across two MCP tool invocations on one request.
api/server/services/ToolService.js	Passes req into userCanUseMCPServers in both tool definition and tool loading paths.
api/server/controllers/agents/v1.js	Threads req into filterAuthorizedTools and MCP permission checks across create/update/duplicate/revert.
api/app/clients/tools/util/handleTools.js	Passes req into the MCP permission check and into MCP tool construction params.

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[danny-avila]

@codex review

[github-actions]

GitNexus: 🚀 deployed

The LibreChat-pr-13419 index is now live on the MCP server.
Deploy run

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep them coming!

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[danny-avila]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. What shall we delve into next?

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[github-actions]

GitNexus: 🚀 deployed

The LibreChat-pr-13419 index is now live on the MCP server.
Deploy run