ChromaDB Remote MCP Server

A Streamable HTTP MCP (Model Context Protocol) server that provides remote access to ChromaDB for AI assistants like Claude. Enables semantic search and vector database operations from mobile devices and remote locations.
Note: This project uses MCP Streamable HTTP (2025-03-26 spec). SSE transport is deprecated.
νκ΅μ΄ λ¬Έμ
Compatible with ALL major AI platforms:
- Claude (Desktop, Mobile, Code)
- Gemini (CLI, Code Assist)
- Cursor, Cline, Windsurf, VS Code Copilot
- and use Remote MCP with any other MCP-compatible client
Features
Remote MCP server that enables all Claude clients (Desktop, Code, Mobile) to access the same self-hosted ChromaDB instance.
- Shared Memory Across Devices - All Claude clients use the same ChromaDB instance
- Self-Hosted & Private - Your data stays on your infrastructure
- Remote Access - Connect from anywhere via Tailscale or public internet
- Complete ChromaDB Support - All CRUD operations via MCP tools
- REST API Proxy - Direct ChromaDB access for Python/JavaScript
- Unified Authentication - Single token protects both MCP and REST API endpoints
- Easy Deployment - One-command installation with Docker
Architecture
Overview
ββββββββββββββββββββββββββββββββ ββββββββββββββββ
β Claude Desktop + Mobile β β Claude Code β
β (Custom Connector - synced) β β (CLI setup) β
ββββββββββββββββ¬ββββββββββββββββ ββββββββ¬ββββββββ
β β
β MCP Remote Connector β
βββββββββββββββ¬ββββββββββββββββ
β HTTPS
βββββββββββΌβββββββββββ
β Remote MCP β
β Server (Node.js) β
β β
β β’ Auth Gateway β
β β’ MCP Protocol β
β β’ REST API Proxy β
βββββββββββ¬βββββββββββ
β
βββββββββββΌβββββββββββ
β ChromaDB β
β (Vector Database) β
β β
β β’ Embeddings β
β β’ Collections β
β β’ Semantic Search β
ββββββββββββββββββββββ
How Clients Connect:
- Claude Desktop + Mobile: Set up once using custom connector in Claude Desktop, and it automatically syncs to the mobile app. Both share the same connection automatically.
- Claude Code: Requires separate setup using
claude mcp add CLI command.
All clients access the same self-hosted ChromaDB through this remote MCP server. Vector embeddings and semantic search results persist across all platforms.
API Endpoints
| Path | Purpose | Client | Authentication |
|---|
/mcp | MCP Protocol | Claude Desktop/Code/Mobile | β
|
/api/v2/* | ChromaDB REST API | Python | β
|
/docs | Swagger UI | Browser (API docs) | β
|
/openapi.json | OpenAPI Spec | API tools | β
|
/health | Health check | Monitoring | β |
How It Works
- Claude Desktop/Mobile: Add MCP server via custom connector (syncs automatically between devices)
- Claude Code: Add MCP server using
claude mcp add CLI command
- Remote MCP Server authenticates requests and translates MCP protocol to ChromaDB operations
- ChromaDB stores and retrieves vector embeddings for semantic search
- Python can also access ChromaDB directly via the proxied REST API
Benefits:
- Same vector database across all clients
- Desktop and mobile share connection automatically
- Self-hosted and private
- Persistent memory across app restarts
- Single source of truth for embeddings
Quick Start
One-Command Installation
curl -fsSL https://raw.githubusercontent.com/meloncafe/chromadb-remote-mcp/release/scripts/install.sh | bash
This will:
- Download
docker-compose.yml and .env.example
- Auto-detect Docker Compose command (
docker-compose or docker compose)
- Auto-generate a secure authentication token (optional)
- Configure ChromaDB data storage location (Docker volume, local directory, or custom path)
- Pull Docker images
- Display your authentication token and connection URL
Manual Installation
Option 1: Docker (Recommended - Pre-built Image)
mkdir chromadb-remote-mcp && cd chromadb-remote-mcp
curl -O https://raw.githubusercontent.com/meloncafe/chromadb-remote-mcp/release/docker-compose.yml
curl -O https://raw.githubusercontent.com/meloncafe/chromadb-remote-mcp/release/.env.example
cp .env.example .env
docker compose up -d
curl http://localhost:8080/health
docker compose logs -f
Option 2: Build from Source
git clone https://github.com/meloncafe/chromadb-remote-mcp.git
cd chromadb-remote-mcp
cp .env.example .env
docker compose -f docker-compose.dev.yml up -d
Option 3: Local Development
git clone https://github.com/meloncafe/chromadb-remote-mcp.git
cd chromadb-remote-mcp
yarn install
cp .env.example .env
yarn build
yarn start
Generate Secure Token
For production use, generate a secure token for MCP_AUTH_TOKEN in .env:
node -e "console.log(require('crypto').randomBytes(32).toString('base64url'))"
openssl rand -base64 32 | tr '+/' '-_' | tr -d '='
Copy the generated token and paste it into your .env file:
MCP_AUTH_TOKEN=your-generated-token-here
Server Endpoints
- MCP:
http://localhost:8080/mcp (via Caddy proxy)
- Health:
http://localhost:8080/health
- ChromaDB API:
http://localhost:8080/api/v2/*
- Swagger UI:
http://localhost:8080/docs
Configuration
Environment Variables (.env file)
All configuration is done through the .env file. Copy .env.example to .env and customize:
| Variable | Description | Default | Required |
|---|
PORT | External port (Caddy reverse proxy) | 8080 | No |
CHROMA_DATA_PATH | ChromaDB data storage path (volume name, ./data, or absolute path) | chroma-data | No |
CHROMA_HOST | ChromaDB host (internal) | chromadb | No |
CHROMA_PORT | ChromaDB port (internal) | 8000 | No |
CHROMA_TENANT | ChromaDB tenant | default_tenant | No |
CHROMA_DATABASE | ChromaDB database | default_database | No |
MCP_AUTH_TOKEN | Authentication token for MCP and REST API | - | Yes (for public access) |
CHROMA_AUTH_TOKEN | ChromaDB auth token (if ChromaDB requires auth) | - | No |
RATE_LIMIT_MAX | Max requests per IP per 15 minutes | 100 | No |
ALLOWED_ORIGINS | Comma-separated list of allowed origins (DNS rebinding protection) | - | No |
Authentication
IMPORTANT: For public internet access (Tailscale Funnel, Cloudflare Tunnel, etc.), you must set MCP_AUTH_TOKEN in your .env file.
Generate a secure token:
node -e "console.log(require('crypto').randomBytes(32).toString('base64url'))"
openssl rand -base64 32 | tr '+/' '-_' | tr -d '='
Edit your .env file:
MCP_AUTH_TOKEN=your-generated-token-here
Then restart the services:
Supported authentication methods (v2.0.0):
-
Authorization: Bearer TOKEN β only supported way to send MCP_AUTH_TOKEN.
- Recommended for service-to-service callers (API clients, scripts, MCP relays).
- Compliant with MCP specification.
- Example:
curl -H "Authorization: Bearer YOUR_TOKEN" https://your-server.com/mcp
-
OAuth 2.1 / OpenID Connect β recommended for human users.
- Set
OIDC_ISSUERS (comma-separated issuer URLs) or OIDC_PRESET=google,github,microsoft.
- Set
OIDC_AUDIENCE to the resource identifier (typically your MCP server's public URL).
- The server publishes RFC 9728 Protected Resource Metadata at
/.well-known/oauth-protected-resource.
- 401 responses include
WWW-Authenticate: Bearer error="...", resource_metadata="..." per RFC 6750.
Removed in v2.0.0: X-Chroma-Token header and ?apiKey= / ?token= / ?api_key= query-parameter auth are no longer accepted. Clients that previously used those paths must migrate to Authorization: Bearer. The ALLOW_QUERY_AUTH env var is ignored.
The server validates the Origin header for browser requests to prevent DNS rebinding attacks. This security feature is enabled by default and protects your local MCP server from malicious websites.
Default allowed origins (always permitted):
- Localhost variants:
localhost, 127.0.0.1, [::1]
- Claude.ai domains:
https://claude.ai, https://api.anthropic.com
Configure additional allowed origins:
If you need to allow additional web applications or custom domains, add them to ALLOWED_ORIGINS in your .env file:
# Add additional custom domains (Claude.ai is already allowed by default)
ALLOWED_ORIGINS=https://myapp.com,https://yourdomain.com
When to configure ALLOWED_ORIGINS:
- β
Using Claude Desktop Custom Connector β No configuration needed (allowed by default)
- β
Accessing from custom web applications β Add your application's domain
- β
Using Swagger UI remotely β Add your server's domain
- β Using Claude Code CLI β Not needed (no Origin header)
- β Using Python/JavaScript clients β Not needed (no Origin header)
- β Local development only β Not needed (localhost is allowed by default)
Example configurations:
# For custom web application
ALLOWED_ORIGINS=https://myapp.com,https://app.mycompany.com
# Multiple custom domains (comma-separated, spaces are trimmed)
ALLOWED_ORIGINS=https://myapp.com, https://api.example.com, https://dashboard.mycompany.com
# Leave empty if you only need Claude.ai and localhost
ALLOWED_ORIGINS=
Note: Claude.ai domains (https://claude.ai, https://api.anthropic.com) and localhost are always allowed, even if ALLOWED_ORIGINS is empty. Server-to-server requests (without Origin header) are always permitted.
Data Storage Configuration
ChromaDB data can be stored in three ways:
-
Docker volume (default): CHROMA_DATA_PATH=chroma-data
- Managed by Docker
- Survives container restarts
- Use
docker volume ls and docker volume inspect chroma-data to locate
-
Local directory: CHROMA_DATA_PATH=./data
- Easy to backup and access
- Stored in installation directory
-
Custom path: CHROMA_DATA_PATH=/path/to/data
- Must be an absolute path
- Useful for mounting external storage
After changing CHROMA_DATA_PATH, restart the services:
Connecting Claude
Claude Desktop + Mobile
Method 1: Custom Connector (Recommended - Pro/Team/Enterprise)
- Open Claude Desktop β Settings β Integrations β Custom Connector
- Click "Add Custom Server"
- Enter:
- Name:
ChromaDB
- URL:
https://your-server.com/mcp (set Authorization: Bearer YOUR_TOKEN in the connector's header config)
Note: Custom connector automatically syncs to the mobile app. Authentication is mandatory for remote access.
Method 2: mcp-remote Wrapper (Free/Pro Users)
If you don't have access to Custom Connectors, use the mcp-remote package as a workaround:
Configuration file location:
- macOS:
~/Library/Application Support/Claude/claude_desktop_config.json
- Windows:
%APPDATA%\Claude\claude_desktop_config.json
Add to configuration file:
{
"mcpServers": {
"chromadb": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://your-server.com/mcp", "--header", "Authorization: Bearer YOUR_TOKEN"]
}
}
}
Restart Claude Desktop after editing the file.
Important: Remote MCP servers cannot be configured directly in claude_desktop_config.json using streamableHttp transport. You must either use Custom Connectors or the mcp-remote wrapper package.
Claude Code
CLI Command:
claude mcp add --transport http chromadb https://your-server.com/mcp
claude mcp add --transport http chromadb https://your-server.com/mcp \
--header "Authorization: Bearer YOUR_TOKEN"
claude mcp add --transport http chromadb https://your-server.com/mcp \
--header "Authorization: Bearer YOUR_TOKEN"
claude mcp list
The MCP server provides these tools for Claude. v2.2.0 expands coverage to 30 tools across collection / document / search / fork / client-info / admin / destructive groups.
Collection Management
chroma_list_collections - List all collections (with limit / offset)
chroma_create_collection - Create a new collection (configuration / schema optional)
chroma_get_or_create_collection - Idempotent create-or-get (v2.2.0)
chroma_modify_collection - Rename / change metadata or configuration (v2.2.0)
chroma_delete_collection - Delete a collection
chroma_get_collection_info - Get collection metadata
chroma_get_collection_count - Get document count (read_level optional)
chroma_count_collections - Total collection count (v2.2.0)
chroma_peek_collection - Preview collection contents
Document Operations
chroma_add_documents - Add documents (with uris for multi-modal)
chroma_upsert_documents - Idempotent insert-or-update (v2.2.0)
chroma_query_documents - Semantic search (with query_uris / ids pre-filter)
chroma_get_documents - Retrieve documents (read_level optional)
chroma_update_documents - Update existing documents (with embeddings / uris)
chroma_delete_documents - Delete by ids and/or where / where_document filter
Server Info (v2.2.0)
chroma_heartbeat - Server heartbeat (nanosecond timestamp)
chroma_get_server_version - Server version string
chroma_get_max_batch_size - Max batch size (for client-side splitting)
chroma_get_user_identity - Current tenant + databases
These 4 tools require ChromaDB's distributed executor (the executor is the chromadb-server-internal frontend layer, not an algorithmic distribution requirement). The single-node open-source server (chromadb/chroma:latest docker) ships with the local executor, which has these methods hard-coded as unimplemented in rust/frontend/src/executor/local.rs and rust/types/src/api_types.rs. To use them you need either Chroma Cloud (CloudClient) or a self-hosted distributed Chroma deployment (Kubernetes multi-component: frontend + query executor + WAL + compactor + object storage).
Hidden by default so single-node deployments don't waste LLM context on tools that always return "not implemented for local executor" / "unsupported for local chroma".
chroma_search - Hybrid dense + sparse search (RRF). The algorithm itself works on a single node; chromadb open-source simply hasn't implemented the search() endpoint in the local executor.
chroma_fork_collection - Zero-copy fork (segment-level operation on object storage β architecturally requires the distributed compactor/storage stack).
chroma_get_fork_count - Fork metadata lookup (depends on the distributed metadata store).
chroma_get_indexing_status - WAL offset + compactor index progress (requires the distributed WAL/compactor services).
chroma_admin_create_database / chroma_admin_get_database / chroma_admin_list_databases
chroma_admin_create_tenant / chroma_admin_get_tenant
Destructive β opt-in (CHROMA_ALLOW_DESTRUCTIVE_OPS=true)
Calls emit a [DESTRUCTIVE] audit line.
chroma_reset_database - Reset entire database (irreversible)
chroma_admin_delete_database - Delete a database (requires both flags)
Using ChromaDB from Python
The MCP server proxies all ChromaDB REST API endpoints, allowing direct access from Python clients.
Python Example
import chromadb
client = chromadb.HttpClient(
host="your-server.com",
port=443,
ssl=True,
headers={
"Authorization": "Bearer YOUR_TOKEN"
}
)
client = chromadb.HttpClient(
host="localhost",
port=8080,
ssl=False,
headers={
"Authorization": "Bearer YOUR_TOKEN"
}
)
collection = client.create_collection("my_collection")
collection.add(
documents=["Document 1", "Document 2"],
ids=["id1", "id2"]
)
results = collection.query(query_texts=["query"], n_results=2)
Alternative authentication:
from chromadb.config import Settings
client = chromadb.HttpClient(
host="your-server.com",
port=443,
ssl=True,
settings=Settings(
chroma_client_auth_provider="chromadb.auth.token_authn.TokenAuthClientProvider",
chroma_client_auth_credentials="YOUR_TOKEN"
)
)
API Documentation
Visit https://your-server.com/docs for Swagger UI documentation of all ChromaDB REST API endpoints.
Deployment
Option 1: Tailscale VPN (Recommended)
Secure access within your Tailscale network:
docker compose up -d
tailscale serve https / http://127.0.0.1:8080
tailscale serve status
Your server is now accessible at https://your-machine.tailXXXXX.ts.net to all devices in your Tailnet.
Advantages:
- Automatic HTTPS certificates
- No public internet exposure
- Encrypted VPN tunnel
- Authentication optional (VPN provides security layer)
Option 2: Tailscale Funnel (Public Internet)
To use Claude Desktop UI Custom Connector or share publicly:
tailscale funnel 8080 on
tailscale serve https / http://127.0.0.1:8080
tailscale serve status
Warning: This exposes your server to the public internet. Authentication is mandatory! Set MCP_AUTH_TOKEN in your environment.
Disable Funnel:
tailscale funnel 8080 off
Option 3: Cloudflare Tunnel
curl -L https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-amd64 -o cloudflared
chmod +x cloudflared
./cloudflared tunnel login
./cloudflared tunnel create chroma-mcp
./cloudflared tunnel --url http://localhost:3000
Option 4: Nginx Reverse Proxy
server {
listen 80;
server_name your-domain.com;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}
Security
Code Quality & Security Analysis
This project follows strict security practices and has resolved all security issues identified by static analysis:
- β
Zero Active Issues: All OWASP and CWE security findings have been resolved
- π Static Analysis: Continuous monitoring with DeepSource
- π‘οΈ Security Standards: Compliant with OWASP Top 10 and Node.js security best practices
- π Automated Scanning: Dependabot, CodeQL, and container vulnerability scanning
For detailed security information, see Security Policy.
Security Recommendations
-
Enable Authentication for Public Access
- Set
MCP_AUTH_TOKEN when using Tailscale Funnel or public internet
- Generate strong tokens:
openssl rand -base64 32 | tr '+/' '-_' | tr -d '='
- Rotate tokens regularly
-
Use HTTPS
- Tailscale provides automatic HTTPS certificates
- Use reverse proxy (Nginx/Caddy) with Let's Encrypt for other deployments
-
Prefer VPN Over Public Internet
- Tailscale Serve (VPN-only) is more secure than Funnel (public)
- Authentication is optional within VPN but mandatory for public access
-
Monitor Access
docker compose logs mcp-server | grep "Unauthorized"
-
Network Isolation
- Keep ChromaDB on private network
- Only expose MCP server to public internet
Testing
Local Testing
curl http://localhost:3000/health
curl -X POST http://localhost:3000/mcp \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
curl http://localhost:3000/api/v2/heartbeat
Remote Testing (with authentication)
curl -X POST https://your-server.com/mcp \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_TOKEN" \
-d '{"jsonrpc":"2.0","method":"tools/list","id":1}'
curl -X POST "https://your-server.com/mcp" \
-H "Authorization: Bearer YOUR_TOKEN" \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"tools/list","id":1}'
curl https://your-server.com/api/v2/heartbeat \
-H "Authorization: Bearer YOUR_TOKEN"
https://your-server.com/docs
Troubleshooting
ChromaDB Connection Failed
curl http://localhost:8000/api/v2/heartbeat
docker run -d -p 127.0.0.1:8000:8000 chromadb/chroma:1.5.9
docker compose logs mcp-server
MCP Server Not Responding
docker compose logs mcp-server
lsof -i :3000
docker compose restart
Claude Desktop Connection Issues
- Restart Claude Desktop
- Verify URL includes
/mcp path
- Confirm transport type is
streamableHttp (not sse)
- Check authentication token if enabled
- For Custom Connector: Ensure Tailscale Funnel is active
TLS Handshake Timeout on Local Network
If you're connecting from the same local network as the server and using Tailscale Funnel HTTPS:
Problem: TLS handshake fails with timeout when accessing https://your-server.ts.net from the same network.
Root cause: Tailscale Funnel has issues with TLS termination when clients on the same LAN try to connect via the public Funnel domain.
Solution: Use direct local network connection instead of Tailscale HTTPS:
claude mcp remove chromadb
claude mcp add chromadb --transport http \
http://192.168.x.x:8080/mcp \
--header "Authorization: Bearer YOUR_TOKEN"
claude mcp add chromadb --transport http \
http://server-hostname:8080/mcp \
--header "Authorization: Bearer YOUR_TOKEN"
Verification:
curl http://192.168.x.x:8080/health
Note: External clients should continue using Tailscale Funnel HTTPS. This issue only affects clients on the same LAN as the server.
Authentication Errors (401)
docker compose exec mcp-server env | grep MCP_AUTH_TOKEN
curl -X POST https://your-server.com/mcp \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"tools/list","id":1}'
curl -X POST https://your-server.com/mcp \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_TOKEN" \
-d '{"jsonrpc":"2.0","method":"tools/list","id":1}'
Development
Building from Source
git clone https://github.com/meloncafe/chromadb-remote-mcp.git
cd chromadb-remote-mcp
yarn install
yarn dev
yarn build
yarn type-check
Testing
The project includes integration tests with Docker-based E2E validation:
yarn test
yarn test:keep
./scripts/test.sh --help
Integration Test Coverage:
- β
Health check endpoint
- β
Authentication (
Authorization: Bearer MCP_AUTH_TOKEN; OAuth 2.1 / OIDC multi-provider)
- β
MCP protocol (tools/list, tools/call)
- β
ChromaDB REST API proxy
- β
Collection CRUD operations
- β
Rate limiting
- β
Unauthorized access handling
Unit Tests:
yarn test:unit
yarn test:unit:watch
yarn test:unit:coverage
yarn test:all
Unit Test Coverage:
- β
Authentication utilities (timing-safe comparison, buffer operations)
- β
Input validation (collection names, document IDs, metadata)
- β
Data processing (response formatting, JSON serialization)
- β
Error message formatting
See __tests__/README.md for detailed testing strategy.
Code Quality & Coverage
This project uses Codecov for code coverage tracking and test analytics.
Docker Development
Local Build and Test
yarn docker:build:local
./scripts/build.sh --platform linux/amd64 --load
docker run -p 3000:3000 \
-e MCP_AUTH_TOKEN=test123 \
devsaurus/chromadb-remote-mcp:latest
yarn docker:build
./scripts/build.sh --version 1.2.3
./scripts/build.sh --repo myuser/my-mcp --version dev
Push to Docker Hub
yarn docker:push
VERSION=1.2.3 yarn docker:push
./scripts/build.sh --version 1.2.3 --push
DOCKER_REPO=myuser/my-mcp ./scripts/build.sh --version 1.2.3 --push
Environment Variables for Docker Scripts:
export DOCKER_REPO=myuser/my-mcp
export VERSION=1.2.3
export DOCKER_USERNAME=myuser
export DOCKER_PASSWORD=mytoken
Development Scripts
All development scripts are located in scripts/:
| Script | Purpose | Usage |
|---|
build.sh | Build and push Docker images | ./scripts/build.sh --help |
test.sh | Run integration tests | ./scripts/test.sh --help |
install.sh | One-command installation | curl ... | bash |
Quick Development Workflow:
vim src/index.ts
yarn dev
yarn test
yarn docker:build:local
docker-compose up
./scripts/build.sh --version 1.2.3 --push
Project Structure
chromadb-remote-mcp/
βββ .github/
β βββ ISSUE_TEMPLATE/ # GitHub issue templates
β βββ workflows/ # GitHub Actions (publish-release, security-scan, chromadb-version-check.yml)
βββ scripts/
β βββ build.sh # Docker build and push script (multi-platform)
β βββ test.sh # Integration test runner
β βββ install.sh # One-command installation
βββ src/
β βββ index.ts # Main server entry point
β βββ chroma-tools.ts # MCP tool definitions and handlers
β βββ types.ts # TypeScript type definitions
βββ docker-compose.yml # Production (prebuilt image)
βββ docker-compose.dev.yml # Development (builds from source)
βββ Dockerfile # MCP server Docker image
βββ .env.example # Environment variables template
βββ package.json # Node.js dependencies
βββ tsconfig.json # TypeScript configuration
βββ SECURITY.md # Security policy
βββ CONTRIBUTING.md # Contribution guidelines
βββ CODE_OF_CONDUCT.md # Code of conduct
βββ CHANGELOG.md # Version history
βββ LICENSE # MIT license
v2.2.3 Release Notes β CVE-2026-45829 Security Hardening
β οΈ Breaking changes β operators upgrading from v2.2.2 or earlier must read this section.
ChromaDB image version pinned (R4)
All docker-compose*.yml files now pin chromadb/chroma to version 1.5.9@sha256:....
Versions 1.0.0β1.5.8 are vulnerable to CVE-2026-45829 (ChromaToast, CVSS 10.0) β
a pre-auth RCE via malicious embedding-function configuration. Do not downgrade the pin.
A CI workflow (.github/workflows/chromadb-version-check.yml) fails the build if any
docker-compose file references a version in the vulnerable range.
Dev fail-open removed (R1, breaking)
Previously, starting the server without MCP_AUTH_TOKEN or OIDC_ISSUERS/OIDC_PRESET
would succeed silently in non-production environments. This behaviour is removed.
The server now refuses to start unless at least one auth method is configured or
ALLOW_INSECURE_NO_AUTH=true is explicitly set.
Migration:
- Production: set
MCP_AUTH_TOKEN or configure OIDC.
- Local dev: add
ALLOW_INSECURE_NO_AUTH=true to your .env.
ChromaDB REST catch-all proxy is now OFF by default (R3, breaking)
The pass-through REST proxy (previously always mounted) is now disabled unless
CHROMA_REST_PROXY_ENABLED=true is set. When disabled, all /api/* requests return 404.
When enabled, the proxy enforces:
- DNS-rebind protection (
validateOriginHeader) β Origin: evil.example β 403
- Authentication (always required;
ALLOW_INSECURE_NO_AUTH does not bypass the proxy)
- Path filter: collection create/modify/delete and embedding-function endpoints are blocked (403)
- Body sanitize:
configuration.embedding_function in POST/PUT/PATCH body β 400
Migration: If you relied on direct /api/v2/* REST passthrough, set
CHROMA_REST_PROXY_ENABLED=true and ensure authentication is configured.
Contributing
Contributions are welcome! Please feel free to submit issues and pull requests.
- Fork the repository
- Create a feature branch (
git checkout -b feature/amazing-feature)
- Commit your changes (
git commit -m 'Add amazing feature')
- Push to the branch (
git push origin feature/amazing-feature)
- Open a Pull Request
License
MIT License
Resources
Support
If you encounter any issues or have questions, please open an issue.
v2.0.0 Configuration
v2.0 introduces collection metadata schema v2, OAuth 2.1 OIDC, configurable embedding providers, and an optional reranker. See MIGRATION.md for the upgrade guide.
Environment variables
| Variable | Purpose |
|---|
EMBEDDING_PROVIDER | chromadb-default (English-only, default) / external / openai_compatible / gemini / voyage |
EMBEDDING_MODEL | Provider-specific model id. Stored in collection metadata. |
EMBEDDING_DIMENSIONS | Vector dimensions. Required for external mode; Gemini accepts 768/1536/3072. |
EMBEDDING_API_BASE | OpenAI-compatible endpoint base URL (Ollama / TEI / Voyage / Together / vLLM). |
EMBEDDING_API_KEY | Bearer key for openai_compatible or voyage providers. |
GEMINI_API_KEY | Google AI Studio API key for the gemini provider. |
CONFIDENCE_THRESHOLD | Default min_score (0-1). Tool argument has priority. |
RERANKER_API_BASE | OpenAI-compatible /rerank endpoint. Reranker is fail-soft. |
RERANKER_API_KEY | Optional bearer key for the reranker. |
RERANKER_MODEL | Reranker model id (default bge-reranker-v2-m3). |
OIDC_ISSUERS | Comma-separated OIDC issuer URLs. |
OIDC_PRESET | Convenience preset names: google,github,microsoft. |
OIDC_AUDIENCE | Expected aud claim. |
OIDC_SCOPES | Comma-separated scopes for the Protected Resource Metadata. |
OIDC_LOG_SUB_MODE | full for raw sub, otherwise SHA-256 first 12 chars (default). |
MCP_AUTH_TOKEN | Service-to-service / CI / internal scripts only. Use OAuth for human users. Coexists with OIDC β either method accepts. |
LEGACY_COLLECTION_COMPAT | true to allow read-only access to legacy v1 collections. Writes are still rejected. |
Recommended embedding + reranker combinations
Verified locally on Korean RAG workloads (2026-05). Pick by priority:
| Priority | Embedding | Reranker | Why |
|---|
| Accuracy first (recommended) | gemini / gemini-embedding-001 / 1536d | cohere / rerank-multilingual-v3.0 | Gemini emits asymmetric queryβdocument vectors (RETRIEVAL_QUERY/RETRIEVAL_DOCUMENT, self-distance β 0.21 in our test); Cohere reorders short KR questionβanswer pairs cleanly. |
| Cost-balanced | voyage / voyage-3 / 1024d | cohere / rerank-multilingual-v3.0 | Voyage embeddings are ~1/2.5 the cost of Gemini and still asymmetric (input_type query/document, self-distance β 0.56). |
| Minimum embedding cost | openai_compatible / text-embedding-3-small / 1536d | cohere / rerank-multilingual-v3.0 | Cheapest hosted embedding; symmetric vectors are weaker on short KR queries, so the reranker is essential. |
| Self-hosted / offline | openai_compatible (Ollama / TEI / vLLM) | TEI bge-reranker-v2-m3 or similar | No external API; latency depends on local hardware. |
Notes from the verification run:
- Voyage
rerank-2 did NOT reorder the short KR questionβanswer pair used in this test β keep Cohere as the rerank default for KR until your own corpus shows otherwise.
- The reranker layer is fail-soft: leave
RERANKER_API_BASE unset to disable reranking without code changes.
- Set
CONFIDENCE_THRESHOLD (or per-call min_score) to drop low-similarity hits; the server emits confidence_gate: "no_confident_match" when every result is filtered.
Docker Compose snippet (Gemini + Google OAuth)
services:
mcp-server:
image: devsaurus/chromadb-remote-mcp:2.0.0
environment:
EMBEDDING_PROVIDER: gemini
EMBEDDING_MODEL: gemini-embedding-001
EMBEDDING_DIMENSIONS: "1536"
GEMINI_API_KEY: ${GEMINI_API_KEY}
OIDC_PRESET: google
OIDC_AUDIENCE: ${OIDC_AUDIENCE}
CONFIDENCE_THRESHOLD: "0.55"
RERANKER_API_BASE: "http://desktop-gpu.tail-xxxx.ts.net:8001"
RERANKER_MODEL: bge-reranker-v2-m3
OAuth flow
- Configure your IdP (Google / GitHub / Microsoft) to issue tokens for an audience that matches
OIDC_AUDIENCE.
- Set
OIDC_PRESET=google (or OIDC_ISSUERS=... for custom IdPs) and OIDC_AUDIENCE=....
- Clients send
Authorization: Bearer <token> to /mcp.
- 401 responses include
WWW-Authenticate: Bearer error="...", resource_metadata="<base>/.well-known/oauth-protected-resource" per RFC 9728.
MCP_AUTH_TOKEN remains valid alongside OAuth β recommended for non-interactive workloads.
Reading legacy v1 collections
Set LEGACY_COLLECTION_COMPAT=true to allow read-only access. Writes (chroma_add_documents / update / delete) on v1 collections still return Error: Cannot write to legacy v1 collection. See MIGRATION.md.