Firebase MCP Server

General-purpose Model Context Protocol (MCP) server for Firebase (Firestore, Storage, Auth, Functions Logging) with schema-driven validation and context-efficient tools.

Features

• @ Mention Support - Reference Firestore documents with @firebase:firestore://users/user-123
• Smart Autocomplete - MRU cache tracks accessed documents for quick re-reference
• Auto-Discovery - Shows both schema-based AND discovered collections
• Path-based schemas - Follows Firebase firestore.rules convention
• Schema evolution - Field status metadata (experimental → official → legacy)
• Hot reload - File watching, no restart needed when schemas change
• Flexible validation - Three modes: strict, warn (default), permissive
• Works without schemas - Discovery mode for exploring unknown databases
• Context-efficient tools - 99% token reduction for large datasets
• Index-aware queries - Validates queries against firestore.indexes.json
• Functions logging - SQL-like queries for Cloud Functions logs with aggregations and label filtering

Install

Add it to your MCP client (e.g. Claude Code) — runs via npx, no global install needed:

{
  "mcpServers": {
    "firebase": {
      "command": "npx",
      "args": ["-y", "@dasasian/firebase-mcp-server", "start", "./firestore-schemas.json"]
    }
  }
}

start takes an optional schema config path (default ./firestore-schemas.json) and an optional indexes path (default ./firestore.indexes.json) — see Schema Format. Firebase auth uses Application Default Credentials.

Or install the CLI globally:

npm install -g @dasasian/firebase-mcp-server
firebase-mcp start ./firestore-schemas.json

Development (from source)

npm install
npm run build
npm run cli -- start --config ./examples/basic/firestore-schemas.json

@ Mention Support (Resources)

Reference Firestore documents directly in Claude Code:

What's the email for @firebase:firestore://users/user-123?
Show me all posts: @firebase:firestore://posts/*

How It Works

When you type @firebase in Claude Code:

Shows schema-based collections (with validation):

• 📋 Users (User account documents)
• 📋 Posts (Blog post documents)
• 📋 Comments (Comments on posts)

Plus auto-discovered collections (no schema):

• 🔍 analytics
• 🔍 sessions
• 🔍 audit_logs

Configuration

# Enable/disable auto-discovery (default: true)
export FIRESTORE_AUTO_DISCOVER=true

# Cache duration in seconds (default: 300 = 5 minutes)
export FIRESTORE_DISCOVERY_CACHE_TTL=300

Auto-discovery cost: ~$0.0003/day (negligible)

Tools

The server ships 33 tools in four groups. Every tool declares MCP annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint) so a client can auto-approve reads and ask before writes.

Choosing which tools to load

All 33 tool definitions cost roughly 12k tokens of context on every session. If you only need part of the surface, narrow it:

# Only Firestore (12 tools, ~4.3k tokens)
firebase-mcp start --tools firestore

# Firestore plus Auth
firebase-mcp start --tools firestore,auth

Or set it in your MCP client config:

export FIREBASE_MCP_TOOLS=firestore,storage

The --tools flag wins over the environment variable. Leaving both unset loads everything, so upgrading never hides a tool you were already using. Calling a tool from a group you switched off returns an error naming the group to add.

Firestore (12) — --tools firestore

• firestore_show_collections — Show collections (read)
• firestore_read — Read document (read)
• firestore_export — Export collection (read)
• firestore_validate — Validate against schema (read)
• firestore_query_select — Query documents (read)
• firestore_query_collection_group — Query collection group (read)
• firestore_count — Count documents (read)
• firestore_sum — Sum a field (read)
• firestore_stats — Collection statistics (read)
• firestore_import — Import document (write, destructive)
• firestore_update — Update documents (write, destructive)
• firestore_delete — Delete documents (write, destructive)

Firebase Auth (6) — --tools auth

• firebase_auth_list_users — List users (read)
• firebase_auth_get_user — Get user (read)
• firebase_auth_create_user — Create user (write)
• firebase_auth_update_user — Update user (write, destructive)
• firebase_auth_delete_user — Delete user (write, destructive)
• firebase_auth_revoke_sessions — Revoke sessions (write, destructive)

Firebase Storage (14) — --tools storage

• firebase_storage_list_buckets — List buckets (read)
• firebase_storage_ls — List files (read)
• firebase_storage_stat — File metadata (read)
• firebase_storage_find — Find files (read)
• firebase_storage_get_url — Get file URL (read)
• firebase_storage_get_access — Get file access (read)
• firebase_storage_read — Download file to a local temp path (write)
• firebase_storage_upload — Upload file (write, destructive)
• firebase_storage_rm — Delete file (write, destructive)
• firebase_storage_cp — Copy file (write, destructive)
• firebase_storage_mv — Move file (write, destructive)
• firebase_storage_sync — Sync bucket to local (write, destructive)
• firebase_storage_push — Push local to bucket (write, destructive)
• firebase_storage_set_access — Set file access (write, destructive)

Cloud Logging (1) — --tools logs

• firebase_functions_logs — Query Cloud Functions logs with SQL-like syntax (write)

firebase_storage_read and firebase_functions_logs are not marked read-only because they write: the first downloads to a local temp file, the second updates its auto-discovered logging schema on disk.

Reading function logs needs an extra IAM role. The Firebase Admin SDK service account has no Cloud Logging access by default, so firebase_functions_logs fails with PERMISSION_DENIED: Permission denied for all log views even when every other tool works. Grant the role and allow a few minutes for it to take effect:

bash

gcloud projects add-iam-policy-binding PROJECT_ID \
  --member="serviceAccount:firebase-adminsdk-xxxxx@PROJECT_ID.iam.gserviceaccount.com" \
  --role="roles/logging.viewAccessor"

roles/logging.viewer alone may not be enough — the error names log views, and the logging.views.access permission is in viewAccessor.

Example queries:

// Discover what functions exist
{"distinct": "functionName"}

// Show recent errors
{"where": [{"field": "severity", "operator": "==", "value": "ERROR"}], "limit": 20}

// Top error patterns with counts (use "message" — structured logs have no textPayload)
{"groupBy": ["message"], "aggregates": [{"field": "*", "operation": "count", "alias": "count"}], "where": [{"field": "severity", "operator": "==", "value": "ERROR"}], "orderBy": [{"field": "count", "direction": "desc"}], "limit": 10}

// Filter by custom labels (e.g., user, environment)
{"where": [{"field": "labels.user_id", "operator": "==", "value": "123"}]}

Schema Format

Schemas follow Firebase's path-based convention:

{
  "schemas": {
    "/organizations/{organizationId}": {
      "description": "Organization documents",
      "schema": {
        "type": "object",
        "required": ["id", "name"],
        "properties": {
          "id": { "type": "string" },
          "name": { "type": "string" }
        }
      }
    },
    "/organizations/{organizationId}/products/{productId}": {
      "description": "Product catalog",
      "schema": {
        "type": "object",
        "properties": {
          "name": { "type": "string" },
          "category": {
            "type": "string",
            "x-status": "legacy",
            "x-replacedBy": "productType"
          },
          "productType": {
            "type": "string",
            "x-status": "experimental"
          }
        }
      },
      "timestampFields": ["createdAt", "updatedAt"]
    }
  }
}

Documentation

• Installation Guide
• @ Mention Support Guide - How to use @firebase:firestore:// references
• Configuration Reference
• Schema Creation Guide
• Functions Logging Guide - Query Cloud Functions logs with SQL-like syntax, aggregations, and custom labels

License

MIT