LibreChat/AGENTS.md
Danny Avila 4b6d68b3b5
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🎛️ feat: DB-Backed Per-Principal Config System (#12354)
*  feat: Add Config schema, model, and methods for role-based DB config overrides

Add the database foundation for principal-based configuration overrides
(user, group, role) in data-schemas. Includes schema with tenantId and
tenant isolation, CRUD methods, and barrel exports.

* 🔧 fix: Add shebang and enforce LF line endings for git hooks

The pre-commit hook was missing #!/bin/sh, and core.autocrlf=true was
converting it to CRLF, both causing "Exec format error" on Windows.
Add .gitattributes to force LF for .husky/* and *.sh files.

*  feat: Add admin config API routes with section-level capability checks

Add /api/admin/config endpoints for managing per-principal config
overrides (user, group, role). Handlers in @librechat/api use DI pattern
with section-level hasConfigCapability checks for granular access control.

Supports full overrides replacement, per-field PATCH via dot-paths, field
deletion, toggle active, and listing.

* 🐛 fix: Move deleteConfigField fieldPath from URL param to request body

The path-to-regexp wildcard syntax (:fieldPath(*)) is not supported by
the version used in Express. Send fieldPath in the DELETE request body
instead, which also avoids URL-encoding issues with dotted paths.

*  feat: Wire config resolution into getAppConfig with override caching

Add mergeConfigOverrides utility in data-schemas for deep-merging DB
config overrides into base AppConfig by priority order.

Update getAppConfig to query DB for applicable configs when role/userId
is provided, with short-TTL caching and a hasAnyConfigs feature flag
for zero-cost when no DB configs exist.

Also: add unique compound index on Config schema, pass userId from
config middleware, and signal config changes from admin API handlers.

* 🔄 refactor: Extract getAppConfig logic into packages/api as TS service

Move override resolution, caching strategy, and signalConfigChange from
api/server/services/Config/app.js into packages/api/src/app/appConfigService.ts
using the DI factory pattern (createAppConfigService). The JS file becomes
a thin wiring layer injecting loadBaseConfig, cache, and DB dependencies.

* 🧹 chore: Rename configResolution.ts to resolution.ts

*  feat: Move admin types & capabilities to librechat-data-provider

Move SystemCapabilities, CapabilityImplications, and utility functions
(hasImpliedCapability, expandImplications) from data-schemas to
data-provider so they are available to external consumers like the
admin panel without a data-schemas dependency.

Add API-friendly admin types: TAdminConfig, TAdminSystemGrant,
TAdminAuditLogEntry, TAdminGroup, TAdminMember, TAdminUserSearchResult,
TCapabilityCategory, and CAPABILITY_CATEGORIES.

data-schemas re-exports these from data-provider and extends with
config-schema-derived types (ConfigSection, SystemCapability union).

Bump version to 0.8.500.

* feat: Add JSON-serializable admin config API response types to data-schemas

Add AdminConfig, AdminConfigListResponse, AdminConfigResponse, and
AdminConfigDeleteResponse types so both LibreChat API handlers and the
admin panel can share the same response contract. Bump version to 0.0.41.

* refactor: Move admin capabilities & types from data-provider to data-schemas

SystemCapabilities, CapabilityImplications, utility functions,
CAPABILITY_CATEGORIES, and admin API response types should not be in
data-provider as it gets compiled into the frontend bundle, exposing
the capability surface. Moved everything to data-schemas (server-only).

All consumers already import from @librechat/data-schemas, so no
import changes needed elsewhere. Consolidated duplicate AdminConfig
type (was in both config.ts and admin.ts).

* chore: Bump @librechat/data-schemas to 0.0.42

* refactor: Reorganize admin capabilities into admin/ and types/admin.ts

Split systemCapabilities.ts following data-schemas conventions:
- Types (BaseSystemCapability, SystemCapability, AdminConfig, etc.)
  → src/types/admin.ts
- Runtime code (SystemCapabilities, CapabilityImplications, utilities)
  → src/admin/capabilities.ts

Revert data-provider version to 0.8.401 (no longer modified).

* chore: Fix import ordering, rename appConfigService to service

- Rename app/appConfigService.ts → app/service.ts (directory provides context)
- Fix import order in admin/config.ts, types/admin.ts, types/config.ts
- Add naming convention to AGENTS.md

* feat: Add DB base config support (role/__base__)

- Add BASE_CONFIG_PRINCIPAL_ID constant for reserved base config doc
- getApplicableConfigs always includes __base__ in queries
- getAppConfig queries DB even without role/userId when DB configs exist
- Bump @librechat/data-schemas to 0.0.43

* fix: Address PR review issues for admin config

- Add listAllConfigs method; listConfigs endpoint returns all active
  configs instead of only __base__
- Normalize principalId to string in all config methods to prevent
  ObjectId vs string mismatch on user/group lookups
- Block __proto__ and all dunder-prefixed segments in field path
  validation to prevent prototype pollution
- Fix configVersion off-by-one: default to 0, guard pre('save') with
  !isNew, use $inc on findOneAndUpdate
- Remove unused getApplicableConfigs from admin handler deps

* fix: Enable tree-shaking for data-schemas, bump packages

- Switch data-schemas Rollup output to preserveModules so each source
  file becomes its own chunk; consumers (admin panel) can now import
  just the modules they need without pulling in winston/mongoose/etc.
- Add sideEffects: false to data-schemas package.json
- Bump data-schemas to 0.0.44, data-provider to 0.8.402

* feat: add capabilities subpath export to data-schemas

Adds `@librechat/data-schemas/capabilities` subpath export so browser
consumers can import BASE_CONFIG_PRINCIPAL_ID and capability constants
without pulling in Node.js-only modules (winston, async_hooks, etc.).

Bump version to 0.0.45.

* fix: include dist/ in data-provider npm package

Add explicit files field so npm includes dist/types/ in the published
package. Without this, the root .gitignore exclusion of dist/ causes
npm to omit type declarations, breaking TypeScript consumers.

* chore: bump librechat-data-provider to 0.8.403

* feat: add GET /api/admin/config/base for raw AppConfig

Returns the full AppConfig (YAML + DB base merged) so the admin panel
can display actual config field values and structure. The startup config
endpoint (/api/config) returns TStartupConfig which is a different shape
meant for the frontend app.

* chore: imports order

* fix: address code review findings for admin config

Critical:
- Fix clearAppConfigCache: was deleting from wrong cache store (CONFIG_STORE
  instead of APP_CONFIG), now clears BASE and HAS_DB_CONFIGS keys
- Eliminate race condition: patchConfigField and deleteConfigField now use
  atomic MongoDB $set/$unset with dot-path notation instead of
  read-modify-write cycles, removing the lost-update bug entirely
- Add patchConfigFields and unsetConfigField atomic DB methods

Major:
- Reorder cache check before principal resolution in getAppConfig so
  getUserPrincipals DB query only fires on cache miss
- Replace '' as ConfigSection with typed BROAD_CONFIG_ACCESS constant
- Parallelize capability checks with Promise.all instead of sequential
  awaits in for loops
- Use loose equality (== null) for cache miss check to handle both null
  and undefined returns from cache implementations
- Set HAS_DB_CONFIGS_KEY to true on successful config fetch

Minor:
- Remove dead pre('save') hook from config schema (all writes use
  findOneAndUpdate which bypasses document hooks)
- Consolidate duplicate type imports in resolution.ts
- Remove dead deepGet/deepSet/deepUnset functions (replaced by atomic ops)
- Add .sort({ priority: 1 }) to getApplicableConfigs query
- Rename _impliedBy to impliedByMap

* fix: self-referencing BROAD_CONFIG_ACCESS constant

* fix: replace type-cast sentinel with proper null parameter

Update hasConfigCapability to accept ConfigSection | null where null
means broad access check (MANAGE_CONFIGS or READ_CONFIGS only).
Removes the '' as ConfigSection type lie from admin config handlers.

* fix: remaining review findings + add tests

- listAllConfigs accepts optional { isActive } filter so admin listing
  can show inactive configs (#9)
- Standardize session application to .session(session ?? null) across
  all config DB methods (#15)
- Export isValidFieldPath and getTopLevelSection for testability
- Add 38 tests across 3 spec files:
  - config.spec.ts (api): path validation, prototype pollution rejection
  - resolution.spec.ts: deep merge, priority ordering, array replacement
  - config.spec.ts (data-schemas): full CRUD, ObjectId normalization,
    atomic $set/$unset, configVersion increment, toggle, __base__ query

* fix: address second code review findings

- Fix cross-user cache contamination: overrideCacheKey now handles
  userId-without-role case with its own cache key (#1)
- Add broad capability check before DB lookup in getConfig to prevent
  config existence enumeration (#2/#3)
- Move deleteConfigField fieldPath from request body to query parameter
  for proxy/load balancer compatibility (#5)
- Derive BaseSystemCapability from SystemCapabilities const instead of
  manual string union (#6)
- Return 201 on upsert creation, 200 on update (#11)
- Remove inline narration comments per AGENTS.md (#12)
- Type overrides as Partial<TCustomConfig> in DB methods and handler
  deps (#13)
- Replace double as-unknown-as casts in resolution.ts with generic
  deepMerge<T> (#14)
- Make override cache TTL injectable via AppConfigServiceDeps (#16)
- Add exhaustive never check in principalModel switch (#17)

* fix: remaining review findings — tests, rename, semantics

- Rename signalConfigChange → markConfigsDirty with JSDoc documenting
  the stale-window tradeoff and overrideCacheTtl knob
- Fix DEFAULT_OVERRIDE_CACHE_TTL naming convention
- Add createAppConfigService tests (14 cases): cache behavior, feature
  flag, cross-user key isolation, fallback on error, markConfigsDirty
- Add admin handler integration tests (13 cases): auth ordering,
  201/200 on create/update, fieldPath from query param, markConfigsDirty
  calls, capability checks

* fix: global flag corruption + empty overrides auth bypass

- Remove HAS_DB_CONFIGS_KEY=false optimization: a scoped query returning
  no configs does not mean no configs exist globally. Setting the flag
  false from a per-principal query short-circuited all subsequent users.
- Add broad manage capability check before section checks in
  upsertConfigOverrides: empty overrides {} no longer bypasses auth.

* test: add regression and invariant tests for config system

Regression tests:
- Bug 1: User A's empty result does not short-circuit User B's overrides
- Bug 2: Empty overrides {} returns 403 without MANAGE_CONFIGS

Invariant tests (applied across ALL handlers):
- All 5 mutation handlers call markConfigsDirty on success
- All 5 mutation handlers return 401 without auth
- All 5 mutation handlers return 403 without capability
- All 3 read handlers return 403 without capability

* fix: third review pass — all findings addressed

Service (service.ts):
- Restore HAS_DB_CONFIGS=false for base-only queries (no role/userId)
  so deployments with zero DB configs skip DB queries (#1)
- Resolve cache once at factory init instead of per-invocation (#8)
- Use BASE_CONFIG_PRINCIPAL_ID constant in overrideCacheKey (#10)
- Add JSDoc to clearAppConfigCache documenting stale-window (#4)
- Fix log message to not say "from YAML" (#14)

Admin handlers (config.ts):
- Use configVersion===1 for 201 vs 200, eliminating TOCTOU race (#2)
- Add Array.isArray guard on overrides body (#5)
- Import CapabilityUser from capabilities.ts, remove duplicate (#6)
- Replace as-unknown-as cast with targeted type assertion (#7)
- Add MAX_PATCH_ENTRIES=100 cap on entries array (#15)
- Reorder deleteConfigField to validate principalType first (#12)
- Export CapabilityUser from middleware/capabilities.ts

DB methods (config.ts):
- Remove isActive:true from patchConfigFields to prevent silent
  reactivation of disabled configs (#3)

Schema (config.ts):
- Change principalId from Schema.Types.Mixed to String (#11)

Tests:
- Add patchConfigField unsafe fieldPath rejection test (#9)
- Add base-only HAS_DB_CONFIGS=false test (#1)
- Update 201/200 tests to use configVersion instead of findConfig (#2)

* fix: add read handler 401 invariant tests + document flag behavior

- Add invariant: all 3 read handlers return 401 without auth
- Document on markConfigsDirty that HAS_DB_CONFIGS stays true after
  all configs are deleted until clearAppConfigCache or restart

* fix: remove HAS_DB_CONFIGS false optimization entirely

getApplicableConfigs([]) only queries for __base__, not all configs.
A deployment with role/group configs but no __base__ doc gets the
flag poisoned to false by a base-only query, silently ignoring all
scoped overrides. The optimization is not safe without a comprehensive
Config.exists() check, which adds its own DB cost. Removed entirely.

The flag is now write-once-true (set when configs are found or by
markConfigsDirty) and only cleared by clearAppConfigCache/restart.

* chore: reorder import statements in app.js for clarity

* refactor: remove HAS_DB_CONFIGS_KEY machinery entirely

The three-state flag (false/null/true) was the source of multiple bugs
across review rounds. Every attempt to safely set it to false was
defeated by getApplicableConfigs querying only a subset of principals.

Removed: HAS_DB_CONFIGS_KEY constant, all reads/writes of the flag,
markConfigsDirty (now a no-op concept), notifyChange wrapper, and all
tests that seeded false manually.

The per-user/role TTL cache (overrideCacheTtl, default 60s) is the
sole caching mechanism. On cache miss, getApplicableConfigs queries
the DB. This is one indexed query per user per TTL window — acceptable
for the config override use case.

* docs: rewrite admin panel remaining work with current state

* perf: cache empty override results to avoid repeated DB queries

When getApplicableConfigs returns no configs for a principal, cache
baseConfig under their override key with TTL. Without this, every
user with no per-principal overrides hits MongoDB on every request
after the 60s cache window expires.

* fix: add tenantId to cache keys + reject PUBLIC principal type

- Include tenantId in override cache keys to prevent cross-tenant
  config contamination. Single-tenant deployments (tenantId undefined)
  use '_' as placeholder — no behavior change for them.
- Reject PrincipalType.PUBLIC in admin config validation — PUBLIC has
  no PrincipalModel and is never resolved by getApplicableConfigs,
  so config docs for it would be dead data.
- Config middleware passes req.user.tenantId to getAppConfig.

* fix: fourth review pass findings

DB methods (config.ts):
- findConfigByPrincipal accepts { includeInactive } option so admin
  GET can retrieve inactive configs (#5)
- upsertConfig catches E11000 duplicate key on concurrent upserts and
  retries without upsert flag (#2)
- unsetConfigField no longer filters isActive:true, consistent with
  patchConfigFields (#11)
- Typed filter objects replace Record<string, unknown> (#12)

Admin handlers (config.ts):
- patchConfigField: serial broad capability check before Promise.all
  to pre-warm ALS principal cache, preventing N parallel DB calls (#3)
- isValidFieldPath rejects leading/trailing dots and consecutive
  dots (#7)
- Duplicate fieldPaths in patch entries return 400 (#8)
- DEFAULT_PRIORITY named constant replaces hardcoded 10 (#14)
- Admin getConfig and patchConfigField pass includeInactive to
  findConfigByPrincipal (#5)
- Route import uses barrel instead of direct file path (#13)

Resolution (resolution.ts):
- deepMerge has MAX_MERGE_DEPTH=10 guard to prevent stack overflow
  from crafted deeply nested configs (#4)

* fix: final review cleanup

- Remove ADMIN_PANEL_REMAINING.md (local dev notes with Windows paths)
- Add empty-result caching regression test
- Add tenantId to AdminConfigDeps.getAppConfig type
- Restore exhaustive never check in principalModel switch
- Standardize toggleConfigActive session handling to options pattern

* fix: validate priority in patchConfigField handler

Add the same non-negative number validation for priority that
upsertConfigOverrides already has. Without this, invalid priority
values could be stored via PATCH and corrupt merge ordering.

* chore: remove planning doc from PR

* fix: correct stale cache key strings in service tests

* fix: clean up service tests and harden tenant sentinel

- Remove no-op cache delete lines from regression tests
- Change no-tenant sentinel from '_' to '__default__' to avoid
  collision with a real tenant ID when multi-tenancy is enabled
- Remove unused CONFIG_STORE from AppConfigServiceDeps

* chore: bump @librechat/data-schemas to 0.0.46

* fix: block prototype-poisoning keys in deepMerge

Skip __proto__, constructor, and prototype keys during config merge
to prevent prototype pollution via PUT /api/admin/config overrides.
2026-03-25 19:39:29 -04:00

8.7 KiB

LibreChat

Project Overview

LibreChat is a monorepo with the following key workspaces:

Workspace Language Side Dependency Purpose
/api JS (legacy) Backend packages/api, packages/data-schemas, packages/data-provider, @librechat/agents Express server — minimize changes here
/packages/api TypeScript Backend packages/data-schemas, packages/data-provider New backend code lives here (TS only, consumed by /api)
/packages/data-schemas TypeScript Backend packages/data-provider Database models/schemas, shareable across backend projects
/packages/data-provider TypeScript Shared Shared API types, endpoints, data-service — used by both frontend and backend
/client TypeScript/React Frontend packages/data-provider, packages/client Frontend SPA
/packages/client TypeScript Frontend packages/data-provider Shared frontend utilities

The source code for @librechat/agents (major backend dependency, same team) is at /home/danny/agentus.


Workspace Boundaries

  • All new backend code must be TypeScript in /packages/api.
  • Keep /api changes to the absolute minimum (thin JS wrappers calling into /packages/api).
  • Database-specific shared logic goes in /packages/data-schemas.
  • Frontend/backend shared API logic (endpoints, types, data-service) goes in /packages/data-provider.
  • Build data-provider from project root: npm run build:data-provider.

Code Style

Naming and File Organization

  • Single-word file names whenever possible (e.g., permissions.ts, capabilities.ts, service.ts).
  • When multiple words are needed, prefer grouping related modules under a single-word directory rather than using multi-word file names (e.g., admin/capabilities.ts not adminCapabilities.ts).
  • The directory already provides context — app/service.ts not app/appConfigService.ts.

Structure and Clarity

  • Never-nesting: early returns, flat code, minimal indentation. Break complex operations into well-named helpers.
  • Functional first: pure functions, immutable data, map/filter/reduce over imperative loops. Only reach for OOP when it clearly improves domain modeling or state encapsulation.
  • No dynamic imports unless absolutely necessary.

DRY

  • Extract repeated logic into utility functions.
  • Reusable hooks / higher-order components for UI patterns.
  • Parameterized helpers instead of near-duplicate functions.
  • Constants for repeated values; configuration objects over duplicated init code.
  • Shared validators, centralized error handling, single source of truth for business rules.
  • Shared typing system with interfaces/types extending common base definitions.
  • Abstraction layers for external API interactions.

Iteration and Performance

  • Minimize looping — especially over shared data structures like message arrays, which are iterated frequently throughout the codebase. Every additional pass adds up at scale.
  • Consolidate sequential O(n) operations into a single pass whenever possible; never loop over the same collection twice if the work can be combined.
  • Choose data structures that reduce the need to iterate (e.g., Map/Set for lookups instead of Array.find/Array.includes).
  • Avoid unnecessary object creation; consider space-time tradeoffs.
  • Prevent memory leaks: careful with closures, dispose resources/event listeners, no circular references.

Type Safety

  • Never use any. Explicit types for all parameters, return values, and variables.
  • Limit unknown — avoid unknown, Record<string, unknown>, and as unknown as T assertions. A Record<string, unknown> almost always signals a missing explicit type definition.
  • Don't duplicate types — before defining a new type, check whether it already exists in the project (especially packages/data-provider). Reuse and extend existing types rather than creating redundant definitions.
  • Use union types, generics, and interfaces appropriately.
  • All TypeScript and ESLint warnings/errors must be addressed — do not leave unresolved diagnostics.

Comments and Documentation

  • Write self-documenting code; no inline comments narrating what code does.
  • JSDoc only for complex/non-obvious logic or intellisense on public APIs.
  • Single-line JSDoc for brief docs, multi-line for complex cases.
  • Avoid standalone // comments unless absolutely necessary.

Import Order

Imports are organized into three sections:

  1. Package imports — sorted shortest to longest line length (react always first).
  2. import type imports — sorted longest to shortest (package types first, then local types; length resets between sub-groups).
  3. Local/project imports — sorted longest to shortest.

Multi-line imports count total character length across all lines. Consolidate value imports from the same module. Always use standalone import type { ... } — never inline type inside value imports.

JS/TS Loop Preferences

  • Limit looping as much as possible. Prefer single-pass transformations and avoid re-iterating the same data.
  • for (let i = 0; ...) for performance-critical or index-dependent operations.
  • for...of for simple array iteration.
  • for...in only for object property enumeration.

Frontend Rules (client/src/**/*)

Localization

  • All user-facing text must use useLocalize().
  • Only update English keys in client/src/locales/en/translation.json (other languages are automated externally).
  • Semantic key prefixes: com_ui_, com_assistants_, etc.

Components

  • TypeScript for all React components with proper type imports.
  • Semantic HTML with ARIA labels (role, aria-label) for accessibility.
  • Group related components in feature directories (e.g., SidePanel/Memories/).
  • Use index files for clean exports.

Data Management

  • Feature hooks: client/src/data-provider/[Feature]/queries.ts[Feature]/index.tsclient/src/data-provider/index.ts.
  • React Query (@tanstack/react-query) for all API interactions; proper query invalidation on mutations.
  • QueryKeys and MutationKeys in packages/data-provider/src/keys.ts.

Data-Provider Integration

  • Endpoints: packages/data-provider/src/api-endpoints.ts
  • Data service: packages/data-provider/src/data-service.ts
  • Types: packages/data-provider/src/types/queries.ts
  • Use encodeURIComponent for dynamic URL parameters.

Performance

  • Prioritize memory and speed efficiency at scale.
  • Cursor pagination for large datasets.
  • Proper dependency arrays to avoid unnecessary re-renders.
  • Leverage React Query caching and background refetching.

Development Commands

Command Purpose
npm run smart-reinstall Install deps (if lockfile changed) + build via Turborepo
npm run reinstall Clean install — wipe node_modules and reinstall from scratch
npm run backend Start the backend server
npm run backend:dev Start backend with file watching (development)
npm run build Build all compiled code via Turborepo (parallel, cached)
npm run frontend Build all compiled code sequentially (legacy fallback)
npm run frontend:dev Start frontend dev server with HMR (port 3090, requires backend running)
npm run build:data-provider Rebuild packages/data-provider after changes
  • Node.js: v20.19.0+ or ^22.12.0 or >= 23.0.0
  • Database: MongoDB
  • Backend runs on http://localhost:3080/; frontend dev server on http://localhost:3090/

Testing

  • Framework: Jest, run per-workspace.
  • Run tests from their workspace directory: cd api && npx jest <pattern>, cd packages/api && npx jest <pattern>, etc.
  • Frontend tests: __tests__ directories alongside components; use test/layout-test-utils for rendering.
  • Cover loading, success, and error states for UI/data flows.

Philosophy

  • Real logic over mocks. Exercise actual code paths with real dependencies. Mocking is a last resort.
  • Spies over mocks. Assert that real functions are called with expected arguments and frequency without replacing underlying logic.
  • MongoDB: use mongodb-memory-server for a real in-memory MongoDB instance. Test actual queries and schema validation, not mocked DB calls.
  • MCP: use real @modelcontextprotocol/sdk exports for servers, transports, and tool definitions. Mirror real scenarios, don't stub SDK internals.
  • Only mock what you cannot control: external HTTP APIs, rate-limited services, non-deterministic system calls.
  • Heavy mocking is a code smell, not a testing strategy.

Formatting

Fix all formatting lint errors (trailing spaces, tabs, newlines, indentation) using auto-fix when available. All TypeScript/ESLint warnings and errors must be resolved.