firebird-sql-mcp 0.1.0a3

Read-only MCP server for Firebird databases

firebird-sql-mcp

Read-only MCP server for Firebird databases. Gives AI assistants (Claude Desktop, Claude Code, Cursor, ...) safe access to a database: browse the schema, run SELECT queries, never write anything. Status: alpha.

Tools

Tool	What it does
list_profiles	Configured connection profiles (never includes secrets)
list_tables	User tables and views, filter by kind or name
describe_table	Columns and types, primary key, foreign keys, indexes
run_query	Run one SELECT/WITH statement, capped by row count and a 1 MiB budget
explain_query	The engine's execution plan, without executing the query

How read-only is enforced

Not by SQL string filtering alone. Every query runs inside a Firebird read-only transaction, so the engine itself rejects writes even if a statement slips past the SQL gate; transactions are always rolled back, never committed. A statement timeout and response caps limit runaway queries, and every query is written to a JSONL audit log. Passwords live in the OS keyring, never in files or logs.

Requirements

• Python 3.11+ and a Firebird client library (fbclient.dll / libfbclient.so); set FBMCP_FB_CLIENT_LIBRARY if it is not on the default search path.
• Firebird server 3.0+ (developed against 5.0); embedded databases work too.

Install and set up

Claude Code, as a plugin (needs uv; details in plugin/README.md):

/plugin marketplace add dimitar-grigorov/firebird-sql-mcp
/plugin install firebird-sql-mcp

Everywhere else, install the package (pip, pipx or uv tool):

pip install firebird-sql-mcp

Then add a profile - one command creates the config, stores the password in the OS keyring and tests the connection. Omit --host for an embedded local file. With the plugin install, prefix the command with uvx --from firebird-sql-mcp:

fbmcp profile add mydb --host localhost --database D:\Data\MYDB.FDB --user SYSDBA

If you installed the package, register the server with your MCP client. Claude Code:

claude mcp add firebird -- fbmcp

Claude Desktop, Cursor and friends (any stdio MCP client just runs fbmcp):

{
  "mcpServers": {
    "firebird": { "command": "fbmcp" }
  }
}

Then ask away: "What tables are in mydb?", "Describe ORDERS", "Show the 10 most recent orders with customer names".

CLI

Command	What it does
fbmcp	Start the stdio MCP server (what the MCP client runs)
fbmcp profile add|set|rm|list	Manage connection profiles
fbmcp cred set|test|rm --profile <name>	Store, verify or remove a keyring password
fbmcp init-config	Create an example profiles.toml to edit by hand

Profile options: --port, --role, --charset (default AUTO: detected from the schema), --none-charset (what charset NONE data is assumed to be, default WIN1251), --timeout-ms (statement timeout, 0 disables).

Configuration

Profiles live in profiles.toml (%APPDATA%\fbmcp on Windows, ~/.config/fbmcp on Linux, ~/Library/Application Support/fbmcp on macOS):

[defaults]
charset = "AUTO"                # AUTO = detect; or a Firebird charset (WIN1251, UTF8, ...)
statement_timeout_ms = 30000

[profiles.mydb]
host = "localhost"
database = 'D:\Data\MYDB.FDB'   # single quotes: no escaping of backslashes
user = "SYSDBA"

Environment variables: FBMCP_PW__<PROFILE> (password override for containers/CI, beats the keyring), FBMCP_FB_CLIENT_LIBRARY (path to the client library), FBMCP_CONFIG_DIR / FBMCP_DATA_DIR (relocate config and audit log).

License

AGPL-3.0.

Firebird® is a registered trademark of the Firebird Foundation Incorporated. This project is independent and not affiliated with or endorsed by the Firebird Project.