A single-binary MCP server for SQL databases. Connect your AI assistant to MySQL/MariaDB, PostgreSQL, or SQLite with zero runtime dependencies.
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- Multi-database — MySQL/MariaDB, PostgreSQL, and SQLite from one binary
- MCP tools — schema discovery (
listDatabases,listTables,listViews,listTriggers,listFunctions,listProcedures,listMaterializedViews), data access (readQuery,writeQuery), DDL (createDatabase,dropDatabase,dropTable), andexplainQuery. Read-only mode hides the write tools (writeQuery,createDatabase,dropDatabase,dropTable). See MCP Tools for per-backend availability. - Single binary — ~7 MB, no Python/Node/Docker needed
- Multiple transports — stdio (for Claude Desktop, Cursor) and HTTP (for remote/multi-client)
- Two-layer config — CLI flags > environment variables, with sensible defaults per backend
macOS, Linux, WSL:
curl -fsSL https://dbmcp.haymon.ai/install.sh | bashWindows PowerShell:
irm https://dbmcp.haymon.ai/install.ps1 | iexWindows CMD:
curl -fsSL https://dbmcp.haymon.ai/install.cmd -o install.cmd && install.cmd && del install.cmdSee the installation docs for Docker, Cargo, and other methods.
Add a .mcp.json file to your project root. MCP clients read this file and configure the server automatically.
Stdio transport — the client starts and manages the server process:
{
"mcpServers": {
"dbmcp": {
"command": "dbmcp",
"args": ["stdio"],
"env": {
"DB_BACKEND": "mysql",
"DB_HOST": "127.0.0.1",
"DB_PORT": "3306",
"DB_USER": "root",
"DB_PASSWORD": "secret",
"DB_NAME": "mydb"
}
}
}
}HTTP transport — you start the server yourself, the client connects to it:
# Start the server first
dbmcp http --db-backend mysql --db-user root --db-name mydb --port 9001{
"mcpServers": {
"dbmcp": {
"type": "http",
"url": "http://127.0.0.1:9001/mcp"
}
}
}Note: The
"type": "http"field is required for HTTP transport. Without it, clients like Claude Code will reject the config.
# MySQL/MariaDB
dbmcp stdio --db-backend mysql --db-host localhost --db-user root --db-name mydb
# PostgreSQL
dbmcp stdio --db-backend postgres --db-host localhost --db-user postgres --db-name mydb
# SQLite
dbmcp stdio --db-backend sqlite --db-name ./data.db
# HTTP transport
dbmcp http --db-backend mysql --db-user root --db-name mydb --host 0.0.0.0 --port 9001DB_BACKEND=mysql DB_USER=root DB_NAME=mydb dbmcp stdioConfiguration is loaded with clear precedence:
CLI flags > environment variables > defaults
Environment variables are typically set by your MCP client (via env or envFile in the server config).
| Subcommand | Description |
|---|---|
stdio |
Run in stdio mode |
http |
Run in HTTP/SSE mode |
version |
Print version information and exit |
A subcommand is required — running dbmcp with no subcommand prints usage help and exits with a non-zero status.
| Flag | Env Variable | Default | Description |
|---|---|---|---|
--db-backend |
DB_BACKEND |
(required) | mysql, mariadb, postgres, or sqlite |
--db-host |
DB_HOST |
localhost |
Database host |
--db-port |
DB_PORT |
backend default | 3306 (MySQL/MariaDB), 5432 (PostgreSQL) |
--db-user |
DB_USER |
backend default | root (MySQL/MariaDB), postgres (PostgreSQL) |
--db-password |
DB_PASSWORD |
(empty) | Database password |
--db-name |
DB_NAME |
(empty) | Database name or SQLite file path |
--db-charset |
DB_CHARSET |
Character set (MySQL/MariaDB only) |
| Flag | Env Variable | Default | Description |
|---|---|---|---|
--db-ssl |
DB_SSL |
false |
Enable SSL |
--db-ssl-ca |
DB_SSL_CA |
CA certificate path | |
--db-ssl-cert |
DB_SSL_CERT |
Client certificate path | |
--db-ssl-key |
DB_SSL_KEY |
Client key path | |
--db-ssl-verify-cert |
DB_SSL_VERIFY_CERT |
true |
Verify server certificate |
| Flag | Env Variable | Default | Description |
|---|---|---|---|
--db-read-only |
DB_READ_ONLY |
true |
Block write queries |
--db-max-pool-size |
DB_MAX_POOL_SIZE |
5 |
Max connection pool size (min: 1) |
--db-connection-timeout |
DB_CONNECTION_TIMEOUT |
(unset) | Connection timeout in seconds (min: 1) |
--db-query-timeout |
DB_QUERY_TIMEOUT |
30 |
Query execution timeout in seconds |
--db-page-size |
DB_PAGE_SIZE |
100 |
Max items per paginated tool response (range 1–500) |
| Flag | Env Variable | Default | Description |
|---|---|---|---|
--log-level |
LOG_LEVEL |
info |
Log level (trace/debug/info/warn/error) |
| Flag | Default | Description |
|---|---|---|
--host |
127.0.0.1 |
Bind host |
--port |
9001 |
Bind port |
--allowed-origins |
localhost variants | Allowed browser origins (comma-separated). Drives both CORS preflight and server-side Origin rejection. |
--allowed-hosts |
localhost,127.0.0.1,::1 |
Trusted Host headers (comma-separated). Enforced server-side; HTTP/2 :authority is honored. |
Lists accessible databases, paginated via cursor / nextCursor. See Cursor Pagination for iteration details. Not available for SQLite.
Lists tables in a database, paginated via cursor / nextCursor. See Cursor Pagination for iteration details.
Parameters: database (defaults to the active database; SQLite has no database parameter), cursor, search, detailed.
search is an optional case-insensitive LIKE/ILIKE pattern with % (any sequence) and _ (single character) as wildcards — pass users% to match names beginning with users, or %order% for substring matching. A bare word with no wildcards matches only an exact table name.
detailed (default false) switches the response shape:
- Brief (default) —
tablesis a sorted JSON array of bare table-name strings. - Detailed (
detailed: true) —tablesis a JSON object keyed by table name; each value carries the table'sschema,kind,owner,comment,columns[],constraints[],indexes[], andtriggers[]. One call returns both the table list and the per-table metadata.
Lists views in a database, paginated via cursor / nextCursor. Available on MySQL/MariaDB, PostgreSQL (public schema), and SQLite. Parameters: database (defaults to the active database; SQLite has no database parameter), cursor, search, detailed. SQLite returns the brief shape only — search and detailed are not accepted there.
search is an optional case-insensitive LIKE/ILIKE pattern with % (any sequence) and _ (single character) as wildcards. The search value must remain identical across paginated calls for cursor continuity.
detailed (default false) switches the response shape:
- Brief (default) —
viewsis a sorted JSON array of bare view-name strings. View names are unique per schema, so no duplicates appear. - Detailed (
detailed: true) —viewsis a JSON object keyed by bare view name; each value carries the per-backend metadata payload. PostgreSQL exposesschema,owner,description,definition. MySQL/MariaDB exposesschema,definer,security,checkOption,updatable,characterSetClient,collationConnection,definition. See thelistViewsreference for source columns, enumerated value sets, and intentional omissions per backend.
See Cursor Pagination for iteration details.
Lists user-defined triggers on tables, paginated via cursor / nextCursor. Internal constraint and foreign-key triggers are excluded. Available on MySQL/MariaDB, PostgreSQL (public schema), and SQLite. Parameters: database (defaults to the active database; SQLite has no database parameter), cursor, search, detailed.
search is an optional case-insensitive LIKE/ILIKE pattern with % (any sequence) and _ (single character) as wildcards. The search value must remain identical across paginated calls for cursor continuity.
detailed (default false) switches the response shape:
- Brief (default) —
triggersis a sorted JSON array of bare trigger-name strings. - Detailed (
detailed: true) —triggersis a JSON object keyed by trigger name; each value carries the per-backend metadata payload (timing, events, definition, and backend-specific extras like PostgreSQLstatus/functionNameor MySQL/MariaDB session-context fields). See thelistTriggersreference for the full per-backend field list.
See Cursor Pagination for iteration details.
Lists user-defined SQL functions, paginated via cursor / nextCursor. PostgreSQL excludes aggregates, window functions, and procedures; MySQL/MariaDB excludes loadable UDFs (mysql.func). Available on MySQL/MariaDB and PostgreSQL (public schema). Not available for SQLite. Parameters: database (defaults to the active database), cursor, search, detailed.
search is an optional case-insensitive LIKE/ILIKE pattern with % (any sequence) and _ (single character) as wildcards. The search value must remain identical across paginated calls for cursor continuity.
detailed (default false) switches the response shape:
- Brief (default) —
functionsis a sorted JSON array of bare function-name strings. PostgreSQL overloads appear once per overload (duplicate name strings are expected). - Detailed (
detailed: true) —functionsis a JSON object keyed by function signature; each value carries the per-backend metadata payload (language, arguments, return type, definition, and backend-specific extras such as PostgreSQLvolatility/strict/parallelSafetyor MySQL/MariaDB session-context fields). PostgreSQL keys arename(arguments)(overloads disambiguate); MySQL/MariaDB keys are bare names (no overloading). See thelistFunctionsreference for the full per-backend field list.
See Cursor Pagination for iteration details.
Lists user-defined stored procedures, paginated via cursor / nextCursor. Available on MySQL/MariaDB and PostgreSQL (public schema, PostgreSQL 11+). Not available for SQLite. Parameters: database (defaults to the active database), cursor, search, detailed.
search is an optional case-insensitive LIKE/ILIKE pattern with % (any sequence) and _ (single character) as wildcards. The search value must remain identical across paginated calls for cursor continuity.
detailed (default false) switches the response shape:
- Brief (default) —
proceduresis a sorted JSON array of bare procedure-name strings. PostgreSQL overloads appear once per overload (duplicate name strings are expected). - Detailed (
detailed: true) —proceduresis a JSON object keyed by procedure signature; each value carries the per-backend metadata payload (language, arguments, security, definition, and backend-specific extras such as PostgreSQLowneror MySQL/MariaDBdeterministic/sqlDataAccess/session-context fields). PostgreSQL keys arename(arguments)(overloads disambiguate; zero-arg procedures key asname()); MySQL/MariaDB keys are bare names (no overloading). See thelistProceduresreference for the full per-backend field list.
See Cursor Pagination for iteration details.
Lists materialized views in the public schema, paginated via cursor / nextCursor. PostgreSQL only — not available for MySQL/MariaDB or SQLite. Parameters: database (defaults to the active database), cursor, search, detailed.
search is an optional case-insensitive ILIKE pattern with % (any sequence) and _ (single character) as wildcards. SQL meta-characters (', ;, --) are bound as parameter values and never interpolated. The search value must remain identical across paginated calls for cursor continuity.
detailed (default false) switches the response shape:
- Brief (default) —
materializedViewsis a sorted JSON array of bare matview-name strings. Matview names are unique per schema, so no duplicates appear. - Detailed (
detailed: true) —materializedViewsis a JSON object keyed by bare matview name; each value carriesschema,owner,description(ornullwhen noCOMMENT ON MATERIALIZED VIEW),definition(the SELECT body verbatim frompg_matviews.definition),populated(falsefor matviews createdWITH NO DATAand never refreshed), andindexed(truewhen at least one index exists;REFRESH MATERIALIZED VIEW CONCURRENTLYadditionally requires a unique index). Detailed mode deliberately omits column metadata,tablespace, storage parameters, and unique-index detection — recoverable viadefinition,listTables(detailed=true), orreadQueryagainstpg_indexes. See thelistMaterializedViewsreference for source columns and operational semantics.
See Cursor Pagination for iteration details.
Executes a read-only SQL query (SELECT, SHOW, DESCRIBE, USE, EXPLAIN). Always enforces SQL validation as defence-in-depth. Parameters: query, database, cursor. SELECT results paginate via cursor / nextCursor; SHOW, DESCRIBE, USE, and EXPLAIN return a single page and ignore cursor. See Cursor Pagination for iteration details.
Executes a write SQL query (INSERT, UPDATE, DELETE, CREATE, ALTER, DROP). Only available when read-only mode is disabled. Parameters: query, database.
Creates a database if it doesn't exist. Only available when read-only mode is disabled. Not available for SQLite. Parameters: database.
Drops an existing database. Refuses to drop the currently connected database. Only available when read-only mode is disabled. Not available for SQLite. Parameters: database.
Drops a table from a database. If the table has foreign key dependents, the database error is surfaced to the user. On PostgreSQL, a cascade parameter is available to force the drop with CASCADE. Only available when read-only mode is disabled. Parameters: database, table, cascade (PostgreSQL only).
Returns the execution plan for a SQL query. Supports an optional analyze parameter for actual execution statistics (PostgreSQL and MySQL/MariaDB). In read-only mode, EXPLAIN ANALYZE is only allowed for read-only statements since it actually executes the query. SQLite uses EXPLAIN QUERY PLAN (no ANALYZE support). Always available regardless of read-only mode. Parameters: query, database, analyze (PostgreSQL/MySQL only).
- Read-only mode (default) — write tools hidden from AI assistant;
readQueryenforces AST-based SQL validation - Single-statement enforcement — multi-statement injection blocked at parse level
- Dangerous function blocking —
LOAD_FILE(),INTO OUTFILE,INTO DUMPFILEdetected in the AST - Identifier validation — database/table names validated against control characters and empty strings
- Origin + Host allowlists — server-side rejection (403) plus CORS preflight; configurable for HTTP transport
- SSL/TLS — configured via individual
DB_SSL_*variables - PII redaction (opt-in, off by default) — when enabled, query tool output passes through a regex-based redactor that rewrites detected PII spans across 24 built-in entity types spanning seven categories: personal (email), financial (cards, IBAN, UK bank accounts, sort and US ABA routing codes, CVV), government IDs (SSN, ITIN, EIN, UK/US passports, NHS, NINO, SIN, VAT), contact (phone), network (IP, URL, MAC), digital identity (API keys, JWTs, PEM private keys), and crypto wallets. Toggle:
--pii/PII_ENABLE. Operator:--pii-operator/PII_OPERATOR— one ofreplace(default, entity-aware placeholders like<EMAIL_ADDRESS>),mask(length-preserving*),redact(drop),hash(SHA-256 hex). Optional subset via--pii-categories/PII_CATEGORIES(comma-separated, e.g.financial,government); unset enables all built-ins. Scope: query tool output payloads only. See PII configuration for the full surface. - Credential redaction — database password is never shown in logs or debug output
# Unit tests
cargo test --workspace --lib --bins
# Integration tests (requires Docker)
./tests/run.sh
# Filter by engine
./tests/run.sh --filter mariadb
./tests/run.sh --filter mysql
./tests/run.sh --filter postgres
./tests/run.sh --filter sqlite
# With MCP Inspector
npx @modelcontextprotocol/inspector ./target/release/dbmcp stdio
# HTTP mode testing
curl -X POST http://localhost:9001/mcp \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"0.1"}}}'This is a Cargo workspace with the following crates:
| Crate | Path | Description |
|---|---|---|
dbmcp |
. (root) |
Main binary — CLI, transports, database backends |
dbmcp-sql |
crates/backend/ |
Shared error types, validation, and identifier utilities |
dbmcp-config |
crates/config/ |
Configuration structs and CLI argument mapping |
dbmcp-server |
crates/server/ |
Shared MCP tool implementations and server info |
dbmcp-mysql |
crates/mysql/ |
MySQL/MariaDB backend handler and operations |
dbmcp-postgres |
crates/postgres/ |
PostgreSQL backend handler and operations |
dbmcp-sqlite |
crates/sqlite/ |
SQLite backend handler and operations |
sqlx-json |
crates/sqlx-json/ |
Type-safe row-to-JSON conversion for sqlx (RowExt trait) |
cargo build # Development build
cargo build --release # Release build (~7 MB)
cargo test # Run tests
cargo clippy --workspace --tests -- -D warnings # Lint
cargo fmt # Format
cargo doc --no-deps # Build documentationThis project is licensed under the MIT License — see the LICENSE file for details.
