A fast, read-only MySQL Server for the Model Context Protocol (MCP) written in Go.
This project exposes safe MySQL introspection tools to Claude Desktop via MCP. Claude can explore databases, describe schemas, and execute controlled read-only SQL queries — ideal for secure development assistance, debugging, analytics, and schema documentation.
- Fully read-only (blocks all non-SELECT/SHOW/DESCRIBE/EXPLAIN)
- Multi-DSN Support: Connect to multiple MySQL or MariaDB instances, switch via tool
- MariaDB Support: Native compatibility with MariaDB 10.x and 11.x
- Vector Search (MySQL 9.0+): Similarity search on vector columns
- MCP tools:
- list_databases, list_tables, describe_table
- run_query (safe and row-limited)
- ping, server_info
- list_connections, use_connection (multi-DSN)
- vector_search, vector_info (MySQL 9.0+)
- Supports MySQL 8.0, 8.4, 9.0+ and MariaDB 10.x, 11.x
- Query timeouts, structured logging, audit logs; optional live token metrics and
/statusdashboard in HTTP mode - Performance: configurable pool/query timeouts, server-side row caps,
explain_queryplan warnings - Single Go binary
- Unit and integration tests (Testcontainers)
- Native integration with Claude Desktop MCP
brew install askdba/tap/mysql-mcp-serverUpdate local installation (after a new release):
brew update && brew upgrade mysql-mcp-serverApple Silicon — “Cannot install under Rosetta 2 in ARM default prefix (/opt/homebrew)”
Your shell is running Homebrew under Rosetta (Intel) while /opt/homebrew is ARM. They must match. Use one of:
- Run upgrades as ARM:
arch -arm64 brew upgrade mysql-mcp-server(orarch -arm64 /opt/homebrew/bin/brew upgrade mysql-mcp-server). - Terminal.app → Get Info → uncheck Open using Rosetta, then open a new terminal.
- Put
/opt/homebrew/binfirst inPATHso you use the ARMbrewand binary.
Claude Desktop: on Apple Silicon, point command at /opt/homebrew/bin/mysql-mcp-server. /usr/local/opt/mysql-mcp-server/... is normally Intel Homebrew and can stay on an old version.
docker pull ghcr.io/askdba/mysql-mcp-server:latestNote: Docker image tags use the raw version number without a leading "v" (e.g.,
1.5.0, notv1.5.0).
Download the latest release from GitHub Releases.
Available for:
- macOS (Intel & Apple Silicon)
- Linux (amd64 & arm64)
- Windows (amd64)
git clone https://github.com/askdba/mysql-mcp-server.git
cd mysql-mcp-server
make buildBinary output: bin/mysql-mcp-server
brew install askdba/tap/mysql-mcp-server
mysql-mcp-server --versionThen follow the client-specific setup in the Claude Desktop, Claude Code, or Cursor IDE sections below.
Tip:
brew info askdba/tap/mysql-mcp-servershows a config reminder after install.
git clone https://github.com/askdba/mysql-mcp-server.git
cd mysql-mcp-server
make buildWhen running from a cloned repo you can also use the interactive setup script:
./scripts/quickstart.shThis will test your MySQL connection, optionally create a read-only MCP user, and generate your Claude Desktop configuration.
Environment variables:
| Variable | Required | Default | Description |
|---|---|---|---|
| MYSQL_DSN | Yes | – | MySQL DSN |
| MYSQL_MAX_ROWS | No | 200 | Max rows returned per query |
| MYSQL_QUERY_TIMEOUT_SECONDS | No | 30 | Query timeout (seconds); wins over MYSQL_QUERY_TIMEOUT when both are set |
| MYSQL_QUERY_TIMEOUT | No | – | Query timeout in milliseconds (e.g. 30000); used only if MYSQL_QUERY_TIMEOUT_SECONDS is unset |
| MYSQL_POOL_SIZE | No | – | Alias for MYSQL_MAX_OPEN_CONNS (pool size); MYSQL_MAX_OPEN_CONNS overrides when both are set |
| MYSQL_MCP_EXTENDED | No | 0 | Enable extended tools (set to 1) |
| MYSQL_MCP_ENABLE_ADD_CONNECTION | No | 0 | Set 1 to expose the MCP tool add_connection (runtime DSN registration; see add_connection). Requires MYSQL_MCP_EXTENDED=1. Not available over the HTTP REST API. |
| MYSQL_MCP_JSON_LOGS | No | 0 | Enable JSON structured logging (set to 1) |
| MYSQL_MCP_TOKEN_TRACKING | No | 0 | Enable estimated token usage tracking (set to 1) |
| MYSQL_MCP_TOKEN_MODEL | No | cl100k_base | Tokenizer encoding to use for estimation |
| MYSQL_MCP_TOKEN_CARD | No | on when MYSQL_MCP_HTTP is set |
/status live token dashboard + listing in GET /api; omit to use default on; set to 0 to disable |
| MYSQL_MCP_AUDIT_LOG | No | – | Path to audit log file |
| MYSQL_MCP_ALLOWED_DATABASES | No | – | Comma-separated schema allowlist (empty = all allowed). With an allowlist, run_query rejects SHOW DATABASES / SHOW DATABASES LIKE—use list_databases. |
| MYSQL_MCP_STRICT_READ_ONLY | No | 0 | Set 1 to enable transaction_read_only=ON on new connections |
| MYSQL_MCP_PROCESS_ADMIN | No | 0 | Set 1 to enable process_list / kill_query (extended); kill_query issues KILL QUERY (cancels the running statement only, not the connection) |
| MYSQL_MCP_READ_AUDIT_TOOL | No | 0 | Set 1 to enable read_audit_log when audit path is set |
| MYSQL_MCP_SLOW_QUERY_TOOL | No | 0 | Set 1 to enable slow_query_log tool (extended) |
| MYSQL_MCP_VECTOR | No | 0 | Enable vector tools for MySQL 9.0+ (set to 1) |
| MYSQL_MCP_HTTP | No | 0 | Enable REST API mode (set to 1); mutually exclusive with stdio MCP |
| MYSQL_MCP_METRICS_HTTP | No | 0 | With stdio MCP only: expose /status + /api/metrics/tokens on MYSQL_HTTP_PORT (same process as Claude/Cursor) |
| MYSQL_HTTP_PORT | No | 9306 | Port for REST API or metrics sidecar |
| MYSQL_HTTP_RATE_LIMIT | No | 0 | Enable rate limiting for HTTP mode (set to 1) |
| MYSQL_HTTP_RATE_LIMIT_RPS | No | 100 | Rate limit: requests per second |
| MYSQL_HTTP_RATE_LIMIT_BURST | No | 200 | Rate limit: burst size |
| MYSQL_MAX_OPEN_CONNS | No | 10 | Max open database connections (overrides MYSQL_POOL_SIZE when both are set) |
| MYSQL_MAX_IDLE_CONNS | No | 5 | Max idle database connections |
| MYSQL_CONN_MAX_LIFETIME_MINUTES | No | 30 | Connection max lifetime in minutes |
| MYSQL_CONN_MAX_IDLE_TIME_MINUTES | No | 5 | Max idle time before connection is closed |
| MYSQL_PING_TIMEOUT_SECONDS | No | 5 | Database ping/health check timeout |
| MYSQL_MCP_DB_RETRY_MAX | No | 3 | Retries for transient errors on run_query and ping (0 disables retries) |
| MYSQL_MCP_DB_RETRY_MAX_INTERVAL_MS | No | 10000 | Max exponential-backoff interval between retries (milliseconds) |
| MYSQL_HTTP_REQUEST_TIMEOUT_SECONDS | No | 60 | HTTP request timeout in REST API mode |
| MYSQL_SSL | No | – | Enable SSL/TLS for connections (true, false, skip-verify, preferred) |
Enable encrypted connections to MySQL servers:
| SSL Value | Description |
|---|---|
true |
Enable TLS with certificate verification |
false |
Disable TLS (default) |
skip-verify |
Enable TLS without certificate verification (self-signed certs) |
preferred |
Maps to skip-verify (Go MySQL driver limitation) |
Note: The Go MySQL driver doesn't support
tls=preferred. When you specifypreferred, it is automatically mapped toskip-verifyto ensure TLS is enabled.
Environment variable:
# Enable SSL for all connections
export MYSQL_SSL="true"
# Or per-connection SSL
export MYSQL_DSN_1_SSL="skip-verify"Config file:
connections:
production:
dsn: "user:pass@tcp(prod:3306)/db?parseTime=true"
ssl: "true"Security — host keys (read this): By default the server verifies the SSH bastion’s host key (same idea as OpenSSH). Without that, a network attacker could present a fake bastion and intercept database traffic. Use a
known_hostsfile (default:~/.ssh/known_hosts) or pin the key withMYSQL_SSH_HOST_KEY_FINGERPRINT. Paths support~. Turning verification off is opt-in only and dangerous: setMYSQL_SSH_STRICT_HOST_KEY_CHECKING=falseor YAMLstrict_host_key_checking: false(JSON:ssh_strict_host_key_checking: false) only if you accept that risk.
Connect to MySQL through an SSH bastion when the database is not directly reachable:
| Variable | Description |
|---|---|
MYSQL_SSH_HOST |
Bastion hostname |
MYSQL_SSH_USER |
SSH username |
MYSQL_SSH_KEY_PATH |
Path to private key file (~ expanded) |
MYSQL_SSH_PORT |
SSH port (default 22) |
MYSQL_SSH_KNOWN_HOSTS |
Path to OpenSSH known_hosts file (optional; default ~/.ssh/known_hosts when verifying) |
MYSQL_SSH_HOST_KEY_FINGERPRINT |
Pin server key, e.g. SHA256:... or legacy MD5:... / aa:bb:... (optional; overrides file lookup for the callback) |
MYSQL_SSH_STRICT_HOST_KEY_CHECKING |
Default strict. Set to false / 0 / no / off to disable host key verification (insecure) |
Environment variables:
export MYSQL_SSH_HOST="bastion.example.com"
export MYSQL_SSH_USER="deploy"
export MYSQL_SSH_KEY_PATH="$HOME/.ssh/id_rsa"
export MYSQL_SSH_KNOWN_HOSTS="$HOME/.ssh/known_hosts"
# Optional: instead of a file, pin the bastion key (from ssh-keygen -lf):
# export MYSQL_SSH_HOST_KEY_FINGERPRINT="SHA256:...."
export MYSQL_DSN="user:pass@tcp(mysql.internal:3306)/mydb?parseTime=true"Config file:
connections:
production:
dsn: "user:pass@tcp(mysql.internal:3306)/mydb?parseTime=true"
ssh:
host: "bastion.example.com"
user: "deploy"
key_path: "~/.ssh/id_rsa"
port: 22 # optional, default 22
strict_host_key_checking: true # default when omitted; false = insecure, opt-in only
known_hosts: "~/.ssh/known_hosts" # optional
host_key_fingerprint: "SHA256:...." # optional alternative to known_hostsConfigure multiple MySQL connections using numbered environment variables:
# Default connection
export MYSQL_DSN="user:pass@tcp(localhost:3306)/db1?parseTime=true"
# Additional connections
export MYSQL_DSN_1="user:pass@tcp(prod-server:3306)/production?parseTime=true"
export MYSQL_DSN_1_NAME="production"
export MYSQL_DSN_1_DESC="Production database"
export MYSQL_DSN_1_SSL="true" # Enable SSL for this connection
export MYSQL_DSN_2="user:pass@tcp(staging:3306)/staging?parseTime=true"
export MYSQL_DSN_2_NAME="staging"
export MYSQL_DSN_2_DESC="Staging database"Or use JSON configuration:
export MYSQL_CONNECTIONS='[
{"name": "production", "dsn": "user:pass@tcp(prod:3306)/db?parseTime=true", "description": "Production", "ssl": "true"},
{"name": "staging", "dsn": "user:pass@tcp(staging:3306)/db?parseTime=true", "description": "Staging"}
]'Runtime vs static DSNs: Connections defined here (env vars, MYSQL_CONNECTIONS, or YAML) are loaded at process startup into the shared ConnectionManager. The optional MCP tool add_connection (requires MYSQL_MCP_EXTENDED=1 and MYSQL_MCP_ENABLE_ADD_CONNECTION=1) can register additional named DSNs later without restart. New names must not collide with existing connection names. Runtime-registered pools use the same global “active” connection as config-loaded ones—see add_connection. There is no separate per-client session; all MCP clients using the same server process share one active DSN unless you run multiple server instances.
As an alternative to environment variables, you can use a YAML or JSON configuration file.
Config file search order:
--config /path/to/config.yaml(command line flag)MYSQL_MCP_CONFIGenvironment variable./mysql-mcp-server.yaml(current directory)~/.config/mysql-mcp-server/config.yaml(user config)/etc/mysql-mcp-server/config.yaml(system config)
Example config file (mysql-mcp-server.yaml):
# Database connections
connections:
default:
dsn: "user:pass@tcp(localhost:3306)/mydb?parseTime=true"
description: "Local development database"
production:
dsn: "readonly:pass@tcp(prod:3306)/prod?parseTime=true"
description: "Production (read-only)"
ssl: "true" # Enable TLS with certificate verification
# Query settings
query:
max_rows: 200
timeout_seconds: 30
# Connection pool
pool:
max_open_conns: 10
max_idle_conns: 5
conn_max_lifetime_minutes: 30
# Features
features:
extended_tools: true
vector_tools: false
# HTTP/REST API (optional)
http:
enabled: false
port: 9306Command line options:
# Use specific config file
mysql-mcp-server --config /path/to/config.yaml
# Validate config file
mysql-mcp-server --validate-config /path/to/config.yaml
# Print current configuration as YAML
mysql-mcp-server --print-config
# Silent mode: suppress INFO/WARN logs (only errors to stderr)
mysql-mcp-server --silent --config /path/to/config.yaml
# Daemon mode: run HTTP server in background (Unix; use with MYSQL_MCP_HTTP=1)
MYSQL_MCP_HTTP=1 mysql-mcp-server --daemon --config /path/to/config.yamlSilent and daemon mode: Use -s / --silent to reduce log noise in production (INFO and WARN are suppressed; ERROR still goes to stderr). Use -d / --daemon to run the HTTP server detached in the background on Unix. For long-running services, use the example systemd unit or launchd plist. See Silent and daemon mode for details.
Priority: Environment variables override config file values, allowing:
- Base configuration in file
- Environment-specific overrides via env vars
- Docker/K8s secret injection via env vars
See examples/config.yaml and examples/config.json for complete examples.
Example:
export MYSQL_DSN="root:password@tcp(127.0.0.1:3306)/mysql?parseTime=true"
export MYSQL_MAX_ROWS=200
export MYSQL_QUERY_TIMEOUT_SECONDS=30Run:
make runCheck the installed version:
mysql-mcp-server --versionOutput:
mysql-mcp-server v1.7.0
Build time: <build time>
Git commit: <git sha>
Edit your Claude Desktop configuration file:
macOS:
~/Library/Application Support/Claude/claude_desktop_config.json
Windows:
%APPDATA%\Claude\claude_desktop_config.json
Linux:
~/.config/Claude/claude_desktop_config.json
Add:
{
"mcpServers": {
"mysql": {
"command": "mysql-mcp-server",
"env": {
"MYSQL_DSN": "user:password@tcp(127.0.0.1:3306)/mydb?parseTime=true",
"MYSQL_MAX_ROWS": "200",
"MYSQL_MCP_EXTENDED": "1"
}
}
}
}Note: If Claude Desktop cannot find the binary, replace
"mysql-mcp-server"with the full path fromwhich mysql-mcp-server.
Token dashboard (/status) in the same process as MCP: stdio MCP does not open HTTP by default. Set MYSQL_MCP_METRICS_HTTP=1 so this instance also listens on MYSQL_HTTP_PORT (default 9306) for http://127.0.0.1:9306/status and /api/metrics/tokens — the same counters as Claude’s tool calls. Use MYSQL_MCP_TOKEN_TRACKING=1 so the dashboard is meaningful. Do not set MYSQL_MCP_HTTP=1 here (that mode replaces MCP with full REST only).
"env": {
"MYSQL_DSN": "user:password@tcp(127.0.0.1:3306)/mydb?parseTime=true",
"MYSQL_MCP_TOKEN_TRACKING": "1",
"MYSQL_MCP_METRICS_HTTP": "1",
"MYSQL_HTTP_PORT": "9306"
}Restart Claude Desktop.
Cursor IDE supports the Model Context Protocol (MCP). Configure it to use mysql-mcp-server:
Edit your Cursor MCP configuration file:
macOS:
~/.cursor/mcp.json
Windows:
%APPDATA%\Cursor\mcp.json
Linux:
~/.config/Cursor/mcp.json
Add:
{
"mcpServers": {
"mysql": {
"command": "mysql-mcp-server",
"env": {
"MYSQL_DSN": "root:password@tcp(127.0.0.1:3306)/mydb?parseTime=true",
"MYSQL_MAX_ROWS": "200",
"MYSQL_MCP_EXTENDED": "1"
}
}
}
}Token dashboard (/status) in the same process as MCP: Same behavior as Claude Desktop — stdio MCP does not open HTTP by default. Set MYSQL_MCP_TOKEN_TRACKING=1, MYSQL_MCP_METRICS_HTTP=1, and MYSQL_HTTP_PORT (default 9306) for http://127.0.0.1:9306/status and /api/metrics/tokens. Do not set MYSQL_MCP_HTTP=1 here (full REST replaces stdio MCP).
"env": {
"MYSQL_DSN": "root:password@tcp(127.0.0.1:3306)/mydb?parseTime=true",
"MYSQL_MAX_ROWS": "200",
"MYSQL_MCP_EXTENDED": "1",
"MYSQL_MCP_TOKEN_TRACKING": "1",
"MYSQL_MCP_METRICS_HTTP": "1",
"MYSQL_HTTP_PORT": "9306"
}Restart Cursor after editing mcp.json.
With Docker:
{
"mcpServers": {
"mysql": {
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MYSQL_DSN=root:password@tcp(host.docker.internal:3306)/mydb?parseTime=true",
"-e", "MYSQL_MCP_EXTENDED=1",
"ghcr.io/askdba/mysql-mcp-server:latest"
]
}
}
}Restart Cursor after saving the configuration.
Claude Code supports MCP servers via the CLI or a project-scoped .mcp.json file.
claude mcp add --transport stdio \
--env MYSQL_DSN="user:password@tcp(127.0.0.1:3306)/mydb?parseTime=true" \
--env MYSQL_MCP_EXTENDED=1 \
mysql -- mysql-mcp-serverThis repo includes a .mcp.json that Claude Code auto-discovers when you open the project. Set your DSN in the shell before starting Claude Code:
export MYSQL_DSN="user:password@tcp(127.0.0.1:3306)/mydb?parseTime=true"
claude # start Claude Code — MySQL tools will be available automaticallyTo use the same config in your own project, copy .mcp.json to your project root and set MYSQL_DSN in your shell.
Verify the integration by asking Claude Code: "List all databases on this MySQL server."
Returns non-system databases.
Input:
{ "database": "employees" }Input:
{ "database": "employees", "table": "salaries" }Input:
{ "sql": "SELECT id, name FROM users LIMIT 5" }Optional database context:
{ "sql": "SELECT * FROM users LIMIT 5", "database": "myapp" }Offset pagination (SELECT/UNION without an existing LIMIT in the SQL): pass offset (zero-based). The tool appends LIMIT (max_rows+1) OFFSET n server-side, returns at most max_rows rows, and sets has_more / next_offset when another page may exist. Do not add your own LIMIT when using offset.
- Rejects non-read-only SQL
- Enforces row limit
- Enforces timeout
- Retries transient connection/network errors with backoff (see
MYSQL_MCP_DB_RETRY_MAX)
Tests database connectivity and returns latency.
Output:
{ "success": true, "latency_ms": 2, "message": "pong" }Returns MySQL server details.
Output:
{
"version": "8.0.36",
"version_comment": "MySQL Community Server - GPL",
"uptime_seconds": 86400,
"current_database": "myapp",
"current_user": "mcp@localhost",
"character_set": "utf8mb4",
"collation": "utf8mb4_0900_ai_ci",
"max_connections": 151,
"threads_connected": 5
}List all configured MySQL connections.
Output:
{
"connections": [
{"name": "production", "dsn": "user:****@tcp(prod:3306)/db", "active": true},
{"name": "staging", "dsn": "user:****@tcp(staging:3306)/db", "active": false}
],
"active": "production"
}Switch to a different MySQL connection.
Input:
{ "name": "staging" }Output:
{
"success": true,
"active": "staging",
"message": "Switched to connection 'staging'",
"database": "staging_db"
}MCP only. Available when the server runs in MCP mode (stdio) with MYSQL_MCP_EXTENDED=1 and MYSQL_MCP_ENABLE_ADD_CONNECTION=1. It registers a new named MySQL connection at runtime and switches the process-wide active connection for that MCP process. There is no HTTP route to register a new DSN. REST API mode (MYSQL_MCP_HTTP=1) is a separate process: GET /api/connections and POST /api/connections/use only list and switch connections loaded in that HTTP server instance—they do not see names added via MCP in a stdio process, and MCP does not reach into a separate HTTP-only deployment.
Enable:
export MYSQL_MCP_EXTENDED=1
export MYSQL_MCP_ENABLE_ADD_CONNECTION=1Input:
{
"name": "analytics",
"dsn": "appuser:secret@tcp(db.example.com:3306)/warehouse?parseTime=true",
"description": "Optional label"
}| Field | Required | Rules |
|---|---|---|
name |
Yes | Non-empty; must not match an existing connection name (atomic check in ConnectionManager). |
dsn |
Yes | Non-empty; must parse as a valid MySQL DSN. root as the MySQL user is rejected at registration time. |
description |
No | Stored with the connection metadata. |
Behavior: builds a ConnectionConfig, opens a pool, Ping() with the tool request context (timeouts/cancellation), then SetActive(name). On activation failure after a successful add, the server removes the new pool (rollback). The active connection applies to all tools and clients on this process until switched again (use_connection or another add_connection).
Output (success):
{
"success": true,
"active": "analytics",
"message": "Added and switched to connection 'analytics'"
}Typical errors (tool returns an error result): duplicate name, invalid DSN, root user blocked, unreachable host (ping failure), activation/rollback failure. See Runtime connection registration (add_connection) for security implications.
Enable with:
export MYSQL_MCP_VECTOR=1Perform similarity search on vector columns.
Input:
{
"database": "myapp",
"table": "embeddings",
"column": "embedding",
"query": [0.1, 0.2, 0.3, ...],
"limit": 10,
"select": "id, title, content",
"distance_func": "cosine"
}Output:
{
"results": [
{"distance": 0.123, "data": {"id": 1, "title": "Doc 1", "content": "..."}},
{"distance": 0.456, "data": {"id": 2, "title": "Doc 2", "content": "..."}}
],
"count": 2
}Distance functions: cosine (default), euclidean, dot
List vector columns in a database.
Input:
{ "database": "myapp" }Output:
{
"columns": [
{"table": "embeddings", "column": "embedding", "dimensions": 768, "index_name": "vec_idx"}
],
"vector_support": true,
"mysql_version": "9.0.0"
}Enable with:
export MYSQL_MCP_EXTENDED=1Runtime registration of additional DSNs (MCP tool add_connection) also requires MYSQL_MCP_ENABLE_ADD_CONNECTION=1 — see add_connection.
List indexes on a table.
{ "database": "myapp", "table": "users" }Get the CREATE TABLE statement.
{ "database": "myapp", "table": "users" }Get execution plan for a SELECT query. Responses include optional warnings (e.g. full table scan, filesort) when the plan suggests optimizations.
{ "sql": "SELECT * FROM users WHERE id = 1", "database": "myapp" }List views in a database.
{ "database": "myapp" }List triggers in a database.
{ "database": "myapp" }List stored procedures.
{ "database": "myapp" }List stored functions.
{ "database": "myapp" }List table partitions.
{ "database": "myapp", "table": "events" }Get database size information.
{ "database": "myapp" }Or get all databases:
{}Get table size information.
{ "database": "myapp" }List foreign key constraints.
{ "database": "myapp", "table": "orders" }List MySQL server status variables.
{ "pattern": "Threads%" }List MySQL server configuration variables.
{ "pattern": "%buffer%" }The server enforces strict SQL validation:
Allowed operations:
SELECT,SHOW,DESCRIBE,EXPLAIN
Blocked patterns:
- Multi-statement queries (semicolons)
- File operations:
LOAD_FILE(),INTO OUTFILE,INTO DUMPFILE - DDL:
CREATE,ALTER,DROP,TRUNCATE,RENAME - DML:
INSERT,UPDATE,DELETE,REPLACE - Admin:
GRANT,REVOKE,FLUSH,KILL,SHUTDOWN - Dangerous functions:
SLEEP(),BENCHMARK(),GET_LOCK() - Transaction control:
BEGIN,COMMIT,ROLLBACK
CREATE USER 'mcp'@'localhost' IDENTIFIED BY 'strongpass';
GRANT SELECT ON *.* TO 'mcp'@'localhost';When MYSQL_MCP_ENABLE_ADD_CONNECTION=1 (and extended mode), any MCP client that can invoke tools may call add_connection. This server exposes MCP over stdio by default; it does not add a separate HTTP Basic/API-key layer beyond whatever protects access to that MCP process (typically local stdio from the host application). Treat MCP access as privileged: anyone who can call tools can attempt to register a new outbound DSN to hosts reachable from the server. If you also run REST API mode (MYSQL_MCP_HTTP=1) in another process or deployment, secure that interface independently—it is separate from MCP.
Controls enforced by the server today:
- DSN parsing: Invalid DSNs are rejected before opening a connection.
- User blocklist: The literal MySQL user
rootis rejected for runtime registration to reduce accidental high-privilege pools. - Duplicate names: Registration is refused if the name already exists (
ConnectionManager); adds are not silently merged with static config names. - Connectivity check: A pool is opened and
Ping()runs before the connection is considered registered; failures do not leave a half-open registration (failed adds are rolled back if activation fails after add). - Read-only mode: If
MYSQL_MCP_STRICT_READ_ONLY=1, new pools still gettransaction_read_only=ONon the driver path like other connections.
Operational guidance: Disable MYSQL_MCP_ENABLE_ADD_CONNECTION (default 0) unless you need runtime registration. Prefer firewall/network policies so the server host can only reach approved database endpoints. Use least-privilege MySQL users in registered DSNs (same as Recommended MySQL User). Review Multi-DSN Configuration for how static and runtime entries coexist in one process.
Enable JSON logs for production:
export MYSQL_MCP_JSON_LOGS=1Output:
{"timestamp":"2025-01-15T10:30:00.123Z","level":"INFO","message":"query executed","fields":{"tool":"run_query","duration_ms":15,"row_count":42}}Enable query audit trail:
export MYSQL_MCP_AUDIT_LOG=/var/log/mysql-mcp-audit.jsonlEach query is logged with timing, success/failure, and row counts.
Enable estimated token counting for tool inputs/outputs to monitor LLM context usage:
export MYSQL_MCP_TOKEN_TRACKING=1
export MYSQL_MCP_TOKEN_MODEL=cl100k_base # default, used by GPT-4/ClaudeOr via YAML config file:
logging:
token_tracking: true
token_model: "cl100k_base"When enabled:
- JSON logs include a
tokensobject with estimated input/output/total tokens - Audit log entries for
run_queryincludeinput_tokensandoutput_tokens - All other tools also emit token estimates when
token_trackingis enabled
Example JSON log output:
{
"level": "INFO",
"msg": "query executed",
"tool": "run_query",
"duration_ms": 45,
"row_count": 10,
"tokens": {
"input_estimated": 25,
"output_estimated": 150,
"total_estimated": 175,
"model": "cl100k_base"
}
}Notes:
- Token counts are estimates using tiktoken encoding, not actual LLM billing
- For payloads exceeding 1MB, a heuristic (~4 bytes per token) is used to prevent memory spikes
- The feature is disabled by default to avoid overhead when not needed
All queries are automatically timed and logged with:
- Execution duration (milliseconds)
- Row count returned
- Tool name
- Truncated query (for debugging)
Configure the pool and how long queries may run (see also MYSQL_POOL_SIZE and MYSQL_QUERY_TIMEOUT / MYSQL_QUERY_TIMEOUT_SECONDS in the configuration table):
export MYSQL_MAX_OPEN_CONNS=20 # Max open connections (or use MYSQL_POOL_SIZE as an alias)
export MYSQL_MAX_IDLE_CONNS=10 # Max idle connections
export MYSQL_CONN_MAX_LIFETIME_MINUTES=60 # Connection lifetime
export MYSQL_QUERY_TIMEOUT=30000 # Optional: timeout in ms (30 s) if you do not use MYSQL_QUERY_TIMEOUT_SECONDSrun_query applies a server-side LIMIT when absent, returns truncated when more rows exist than the cap (non-pagination mode), returns has_more / next_offset when offset pagination is used, and may warning on SELECT *. Use explain_query for plan warnings (full scans, filesort, etc.).
MySQL max_execution_time vs MCP timeouts: The server enforces MYSQL_QUERY_TIMEOUT_SECONDS (or MYSQL_QUERY_TIMEOUT in ms) on the Go side for every tool. That is independent of the MySQL session variable max_execution_time (often 0, meaning “no engine-side cap”). For operator clarity: configure MCP query timeout for how long the client should wait; configure MySQL if you also want the optimizer to abort expensive SELECTs.
Concurrent tool calls: Each parallel MCP tool call may use a pooled connection. If the host issues several tools at once, set MYSQL_MAX_OPEN_CONNS (alias MYSQL_POOL_SIZE) high enough—e.g. 10–20—so threads do not queue behind a single connection.
| Variable | Purpose |
|---|---|
MYSQL_MCP_ALLOWED_DATABASES |
Comma-separated schema allowlist. When set, tools that take a database argument must use an allowed name; list_databases / database_size only expose allowed schemas; run_query requires database and cannot be used to hop schemas via omission. run_query rejects SHOW DATABASES and SHOW DATABASES LIKE (use list_databases). Qualified names in SQL, EXPLAIN (including FORMAT= / EXTENDED), and inner DML in EXPLAIN are checked against the allowlist. slow_query_log (table mode) only returns mysql.slow_log rows whose db column matches an allowed schema (case-insensitive); rows with null/empty db are omitted. |
MYSQL_MCP_STRICT_READ_ONLY |
When 1, new driver connections run with transaction_read_only=ON (harder to accidentally issue writes if grants allow them). |
MYSQL_MCP_PROCESS_ADMIN |
Enables process_list and kill_query (issues KILL QUERY, not connection kill; plus HTTP /api/processlist, /api/kill). Requires appropriate MySQL privileges (CONNECTION_ADMIN / PROCESS, etc.). |
MYSQL_MCP_READ_AUDIT_TOOL |
Enables read_audit_log when MYSQL_MCP_AUDIT_LOG is set (tail of the audit JSON file). |
MYSQL_MCP_SLOW_QUERY_TOOL |
Enables slow_query_log (reads mysql.slow_log when log_output includes TABLE, otherwise returns file settings). |
server_info: Pass detailed: true (MCP) or ?detailed=1 (HTTP) for ping latency, Threads_running, Slow_queries, Questions, and InnoDB buffer pool hit rate when stats are available. If MYSQL_MCP_TOKEN_TRACKING=1, token_metrics is always included (cumulative since process start).
YAML file equivalents live under security: in the config file (allowed_databases, strict_read_only, process_admin, read_audit_tool, slow_query_tool).
- Go 1.24+
- Docker and Docker Compose (for integration tests)
- MySQL client (optional, for manual database access)
Run unit tests (no external dependencies):
make testIntegration tests run against real MySQL instances using Docker Compose.
Test against MySQL 8.0 (default):
make test-integration-80Test against MySQL 8.4:
make test-integration-84Test against MySQL 9.0:
make test-integration-90Test against all supported versions (MySQL & MariaDB):
make test-integration-allTest specifically against MariaDB 11.4:
make test-integration-mariadb-11The Sakila sample database provides comprehensive integration testing with a realistic DVD rental store schema featuring:
- 16 tables with foreign key relationships
- Views, stored procedures, and triggers
- FULLTEXT indexes and ENUM/SET types
- Sample data for complex query testing
Run Sakila tests:
# Against MySQL 8.0
make test-sakila
# Against MySQL 8.4
make test-sakila-84
# Against MySQL 9.0
make test-sakila-90For a multi-version Sakila test matrix (including alternate ports and health-check helpers), see test-steps.md at the repo root (canonical) or docs/sakila-test-steps.md.
The Sakila tests cover:
- Multi-table JOINs (film→actors, customer→address→city→country)
- Aggregation queries (COUNT, SUM, AVG, GROUP BY)
- Subqueries (IN, NOT IN, correlated)
- View queries
- FULLTEXT search
- Index and foreign key verification
Run SQL injection and validation security tests:
make test-securityStart and stop test MySQL containers manually:
# Start MySQL 8.0 container
make test-mysql-up
# Start all MySQL versions (8.0, 8.4, 9.0)
make test-mysql-all-up
# Stop all test containers
make test-mysql-down
# View container logs
make test-mysql-logsWhen running tests manually, set the DSN:
# MySQL 8.0 (host port 13306 in docker-compose.test.yml — avoids local MySQL on 3306)
export MYSQL_TEST_DSN="mcpuser:mcppass00@tcp(127.0.0.1:13306)/testdb?parseTime=true"
# MySQL 8.4 (port 3307)
export MYSQL_TEST_DSN="mcpuser:mcppass00@tcp(127.0.0.1:3307)/testdb?parseTime=true"
# MySQL 9.0 (port 3308)
export MYSQL_TEST_DSN="mcpuser:mcppass00@tcp(127.0.0.1:3308)/testdb?parseTime=true"Test credentials are mcpuser / mcppass00 (see tests/sql/mcp_test_user.sql). On testdb, this user has DDL/DML so integration tests can create fixtures; sakila stays read-only via mcp_test_user_sakila.sql. After upgrading an existing Docker volume, recreate it so init scripts run: docker compose -f docker-compose.test.yml down -v.
Prefer 127.0.0.1 over localhost when the database runs in Docker (especially on macOS): localhost may resolve to IPv6 (::1) while the published port is IPv4-only, causing connection timeouts until the DSN uses 127.0.0.1.
The mysql80 service publishes 13306 on the host (not 3306) so integration tests do not accidentally connect to a different MySQL instance already listening on 3306.
Then run tests directly:
go test -v -tags=integration ./tests/integration/...Integration tests use two databases:
testdb (tests/sql/init.sql):
- Tables:
users,orders,products,special_data - Views:
user_orders - Stored procedures:
get_user_by_id - Sample test data for basic integration tests
sakila (tests/sql/sakila-schema.sql, tests/sql/sakila-data.sql):
- 16 tables:
actor,film,customer,rental,payment,inventory, etc. - 6 views:
film_list,customer_list,staff_list,sales_by_store, etc. - Stored functions and procedures
- FULLTEXT indexes on
film_text - Realistic sample data (50 actors, 30 films, 10 customers, 20 rentals)
Basic usage:
docker run -e MYSQL_DSN="user:password@tcp(host.docker.internal:3306)/mydb" \
ghcr.io/askdba/mysql-mcp-server:latestNote: Use
host.docker.internalinstead oflocalhostto connect from inside the container to MySQL on your host machine (macOS/Windows).
With extended tools enabled:
docker run \
-e MYSQL_DSN="user:password@tcp(host.docker.internal:3306)/mydb" \
-e MYSQL_MCP_EXTENDED=1 \
ghcr.io/askdba/mysql-mcp-server:latestWith all options:
docker run \
-e MYSQL_DSN="user:password@tcp(host.docker.internal:3306)/mydb" \
-e MYSQL_MCP_EXTENDED=1 \
-e MYSQL_MCP_VECTOR=1 \
-e MYSQL_MAX_ROWS=500 \
-e MYSQL_QUERY_TIMEOUT_SECONDS=60 \
ghcr.io/askdba/mysql-mcp-server:latestEdit ~/Library/Application Support/Claude/claude_desktop_config.json:
{
"mcpServers": {
"mysql": {
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MYSQL_DSN=user:password@tcp(host.docker.internal:3306)/mydb",
"ghcr.io/askdba/mysql-mcp-server:latest"
]
}
}
}With extended tools:
{
"mcpServers": {
"mysql": {
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MYSQL_DSN=user:password@tcp(host.docker.internal:3306)/mydb",
"-e", "MYSQL_MCP_EXTENDED=1",
"ghcr.io/askdba/mysql-mcp-server:latest"
]
}
}
}services:
mysql:
image: mysql:8.4
environment:
MYSQL_ROOT_PASSWORD: rootpass
MYSQL_DATABASE: testdb
ports:
- "3306:3306"
mcp:
image: ghcr.io/askdba/mysql-mcp-server:latest
depends_on:
- mysql
environment:
MYSQL_DSN: "root:rootpass@tcp(mysql:3306)/testdb?parseTime=true"
MYSQL_MCP_EXTENDED: "1"Run:
docker compose updocker build -t mysql-mcp-server .Enable HTTP REST API mode to use with ChatGPT, Gemini, or any HTTP client:
export MYSQL_DSN="user:password@tcp(localhost:3306)/mydb"
export MYSQL_MCP_HTTP=1
export MYSQL_HTTP_PORT=9306 # Optional, defaults to 9306
mysql-mcp-serverEnable per-IP rate limiting for production deployments:
export MYSQL_HTTP_RATE_LIMIT=1
export MYSQL_HTTP_RATE_LIMIT_RPS=100 # 100 requests/second
export MYSQL_HTTP_RATE_LIMIT_BURST=200 # Allow bursts up to 200When rate limited, clients receive HTTP 429 (Too Many Requests) with a Retry-After: 1 header.
To run the REST API server in the background or under a process manager:
- Unix (foreground detach):
MYSQL_MCP_HTTP=1 mysql-mcp-server --daemon --config /path/to/config.yaml(forks and exits the parent; child runs detached). - systemd: Copy and customize contrib/systemd/mysql-mcp-server.service, then
systemctl enable --now mysql-mcp-server. - macOS launchd: Copy and customize contrib/launchd/com.askdba.mysql-mcp-server.plist into
~/Library/LaunchAgents/or/Library/LaunchDaemons/. - Windows: Use a Windows Service wrapper or run in a terminal;
--daemonis not supported.
Use --silent to suppress INFO/WARN logs when running under a service manager. See docs/silent-and-daemon.md.
Discovery (GET /api): The JSON response includes an endpoints map that lists only routes the server has registered for the current configuration—same rules as the mux: core routes always; extended routes only if MYSQL_MCP_EXTENDED=1; /api/processlist and /api/kill only if extended and MYSQL_MCP_PROCESS_ADMIN=1; /api/audit-log only if extended and read-audit is enabled (MYSQL_MCP_READ_AUDIT_TOOL=1 with MYSQL_MCP_AUDIT_LOG); /api/slow-log only if extended and MYSQL_MCP_SLOW_QUERY_TOOL=1; vector routes only if MYSQL_MCP_VECTOR=1; /status appears in the index only when the token card is enabled. modes in the JSON reflects extended, vector, and token_card.
Runtime DSN registration: There is no HTTP route to register a new connection. The MCP tool add_connection (optional; MYSQL_MCP_EXTENDED=1 and MYSQL_MCP_ENABLE_ADD_CONNECTION=1) is the only supported registration path and applies to the MCP (stdio) process only. In REST API mode, the process never registers tools; GET /api/connections lists only connections configured for that HTTP server process (not connections added by MCP elsewhere).
| Method | Endpoint | Description |
|---|---|---|
| GET | /health |
Health check |
| GET | /api |
API index: registered endpoints + modes (see Discovery above) |
| GET | /api/databases |
List databases |
| GET | /api/tables?database= |
List tables |
| GET | /api/describe?database=&table= |
Describe table |
| POST | /api/query |
Run SQL query |
| GET | /api/ping |
Ping database |
| GET | /api/server-info |
Server info |
| GET | /api/connections |
List connections (masked DSNs) known to this HTTP server process (config-loaded; no MCP add_connection in REST mode) |
| POST | /api/connections/use |
Switch active connection: JSON body {"name": "<connection_name>"}. Invalid JSON or missing name → 400. Unknown connection name → 200 with success: false in the JSON body (same semantics as MCP use_connection). |
POST /api/connections/use response: JSON with success, active, message, database when applicable (see Response Format).
Not implemented over HTTP: POST /api/connections (register new DSN) — use MCP add_connection when enabled.
Extended endpoints (requires MYSQL_MCP_EXTENDED=1):
| Method | Endpoint | Description |
|---|---|---|
| GET | /api/indexes?database=&table= |
List indexes |
| GET | /api/create-table?database=&table= |
Show CREATE TABLE |
| POST | /api/explain |
Explain query |
| GET | /api/views?database= |
List views |
| GET | /api/triggers?database= |
List triggers |
| GET | /api/procedures?database= |
List procedures |
| GET | /api/functions?database= |
List functions |
| GET | /api/partitions?database=&table= |
List table partitions |
| GET | /api/size/database?database= |
Database size |
| GET | /api/size/tables?database= |
Table sizes |
| GET | /api/foreign-keys?database= |
Foreign keys |
| GET | /api/status?pattern= |
Server status |
| GET | /api/variables?pattern= |
Server variables |
| GET | /api/audit-log?lines= |
Tail lines from the MCP audit log (JSON). Listed only when extended and MYSQL_MCP_READ_AUDIT_TOOL=1 with MYSQL_MCP_AUDIT_LOG configured. |
| GET | /api/slow-log?limit= |
Slow query log rows or file/table settings. Listed only when extended and MYSQL_MCP_SLOW_QUERY_TOOL=1. |
| GET | /api/processlist |
Active MySQL threads (SHOW FULL PROCESSLIST). Listed only when extended and MYSQL_MCP_PROCESS_ADMIN=1. Requires MySQL PROCESS (or equivalent) to succeed. |
| POST | /api/kill |
Cancel the current statement on a connection: JSON body {"id": <positive integer>} (same id as /api/processlist). Executes KILL QUERY—the client connection stays open. Listed only when extended and MYSQL_MCP_PROCESS_ADMIN=1. Requires privilege to run KILL QUERY for that thread (e.g. CONNECTION_ADMIN or PROCESS as applicable). |
Vector endpoints (requires MYSQL_MCP_VECTOR=1):
| Method | Endpoint | Description |
|---|---|---|
| POST | /api/vector/search |
Vector similarity search |
| GET | /api/vector/info?database= |
Vector column info |
Token metrics (HTTP mode; /status defaults on when MYSQL_MCP_HTTP is set—use MYSQL_MCP_TOKEN_CARD=0 to hide it; YAML features.token_card applies when not using that default):
| Method | Endpoint | Description |
|---|---|---|
| GET | /api/metrics/tokens |
Cumulative token usage, cost estimate, recent queries (always registered; zeros when tracking off) |
| GET | /status |
Live HTML dashboard (auto-refresh); listed in GET /api when the feature is enabled |
List databases:
curl http://localhost:9306/api/databasesRun a query:
curl -X POST http://localhost:9306/api/query \
-H "Content-Type: application/json" \
-d '{"sql": "SELECT * FROM users LIMIT 5", "database": "myapp"}'Get server info:
curl http://localhost:9306/api/server-infoList / switch connections (no HTTP “add” endpoint):
curl http://localhost:9306/api/connections
curl -X POST http://localhost:9306/api/connections/use \
-H "Content-Type: application/json" \
-d '{"name": "staging"}'Registering a new DSN at runtime is MCP-only via the add_connection tool when MYSQL_MCP_ENABLE_ADD_CONNECTION=1 (see add_connection).
All responses follow this format:
{
"success": true,
"data": { ... }
}Error responses:
{
"success": false,
"error": "error message"
}- Start the REST API server on a publicly accessible host
- Create a Custom GPT with Actions
- Import the OpenAPI schema from
/api - Configure authentication if needed
docker run -p 9306:9306 \
-e MYSQL_DSN="user:password@tcp(host.docker.internal:3306)/mydb" \
-e MYSQL_MCP_HTTP=1 \
-e MYSQL_MCP_EXTENDED=1 \
ghcr.io/askdba/mysql-mcp-server:latest- SQL Query Optimization Guide: Practical optimization patterns and query rewriting techniques using the Stack Exchange schema.
- Comprehensive MySQL Query Optimization Guide: Deep technical insights into the query optimizer, advanced indexing strategies, execution plan analysis, and operational best practices.
cmd/mysql-mcp-server/
├── main.go -> Server entrypoint and tool registration
├── types.go -> Input/output struct types for tools
├── tools.go -> Core MCP tool handlers
├── tools_extended.go -> Extended MCP tool handlers
├── http.go -> HTTP REST API handlers and server
├── connection.go -> Multi-DSN connection manager
└── logging.go -> Structured and audit logging
internal/
├── api/ -> HTTP middleware and response utilities
├── config/ -> Configuration loader from environment
├── mysql/ -> MySQL client wrapper + tests
└── util/ -> Shared utilities (SQL validation, identifiers)
examples/ -> Example configs and test data
scripts/ -> Quickstart and utility scripts
bin/ -> Built binaries
The examples/ folder contains:
claude_desktop_config.json- Example Claude Desktop configurationtest-dataset.sql- Demo database with tables, views, and sample data
Load the test dataset:
mysql -u root -p < examples/test-dataset.sqlThis creates a mcp_demo database with:
- 5 categories, 13 products, 8 customers
- 9 orders with 16 order items
- Views:
order_summary,product_inventory - Stored procedure:
GetCustomerOrders - Stored function:
GetProductStock
make fmt # Format code
make lint # Run linter
make test # Run unit tests
make build # Build binary
make release # Build release binariesReleases are automated via GitHub Actions and GoReleaser. Full checklist: docs/releasing.md.
Quick steps: update CHANGELOG.md, commit, then git tag vX.Y.Z and git push origin vX.Y.Z. After the workflow runs, complete post-release steps (CHANGELOG on main if needed, Homebrew tap README, local brew upgrade). See the doc for details.
Apache License 2.0
© 2025 Alkin Tezuysal
