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MCP server plugin · listing tai42/mcp-dynamic-postgres

Install

tai plugins install tai42-mcp-dynamic-postgres

Permissions

Capability	Declared
Network	yes
Subprocess	no
Filesystem	yes

Provides

mcp-dynamic-postgres

MCP server — Schema-driven generator for safe, scoped PostgreSQL DML tools in FastMCP agent systems Point the server at a PostgreSQL database and it introspects the schema and generates one typed MCP tool per DML operation per table. What the agent can reach is set two ways that must agree: the CLI flags below decide which tools exist, and the PostgreSQL role you connect as decides what those tools can physically do. Connect as a dedicated least-privilege role, never a superuser.

Connection settings

Connection and pooling come from environment variables. PG_DB, PG_USER, and PG_PASSWORD have no default — a missing one fails at startup rather than connecting with a phantom value.

Variable	Default	Effect
`PG_HOST`	`localhost`	PostgreSQL host.
`PG_PORT`	`5432`	PostgreSQL port.
`PG_DB`	required	Database name.
`PG_USER`	required	Database user; use a least-privilege role.
`PG_PASSWORD`	required	Database password. Held as a secret.
`PG_STATEMENT_TIMEOUT`	`30000`	Per-connection `statement_timeout` in ms (`0` disables), capping a runaway query.
`PG_POOL_MIN_SIZE`	`1`	Minimum pooled connections.
`PG_POOL_MAX_SIZE`	`10`	Maximum pooled connections.
`PG_POOL_TIMEOUT`	`10`	Pool acquire timeout (seconds).
`PG_POOL_MAX_LIFETIME`	`300`	Maximum connection lifetime (seconds).
`TOOLS_DIR`	`~/.cache/tai42-mcp-dynamic-postgres/tools`	Where generated tool files are written.

Scoping flags

The flags decide which tools are generated and how permissive they are.

Flag	Default	Effect
`--overwrite / --no-overwrite`	on	Regenerate tool files on startup so they track the schema; `--no-overwrite` reuses existing files.
`--readonly`	off	Generate only `select`/`select_joined` tools — no insert, update, or delete.
`--allow-unfiltered`	off	Allow `update`/`delete` to run without a `WHERE` filter (affects every row). Off means unfiltered writes raise.
`--select-joined a,b,c`	—	Generate a joined select over the given tables (repeatable).
`--ignore-insert-column`	`id`	Column to exclude from insert inputs (repeatable).
`--ignore-update-column`	`id`	Column to exclude from update inputs (repeatable).
`--ignore-select-column`	—	Column to exclude from select output models (repeatable).
`--ignore-select-joined-column`	—	Column to exclude from joined select models (repeatable).
`-t, --transport`	`stdio`	`stdio`, `http`, `sse`, or `streamable-http`.
`--host`	`127.0.0.1`	Bind host (HTTP/SSE transports only).
`--port`	`8000`	Bind port (HTTP/SSE transports only).

Transport

The default transport is stdio: an MCP client launches the server as a subprocess and speaks over stdin/stdout. Wire it into a client’s server list, passing the connection settings through env:

{
  "mcpServers": {
    "postgres": {
      "command": "uvx",
      "args": ["tai42-mcp-dynamic-postgres", "--readonly"],
      "env": { "PG_DB": "dbname", "PG_USER": "agent", "PG_PASSWORD": "secret" }
    }
  }
}

For a network-mounted server, choose an HTTP transport and bind a host and port (--host / --port apply only here):

uvx tai42-mcp-dynamic-postgres -t http --host 0.0.0.0 --port 8000

Generated tools

For a table public.events you get (unless --readonly):

select_public_events(where, order_by, limit, offset)
insert_public_events(params, raise_on_conflict)
update_public_events(data, where)
delete_public_events(where)

Column types map to native Python: temporal columns to datetime/date/time, uuid to uuid.UUID, numeric/decimal to Decimal, json/jsonb to Any, and array columns to list[...]. insert returns the table’s real primary key (a scalar list for a single-column key, a list of lists for a composite key, or the affected row count when the table has none); columns with a database default are omittable. order_by items take an optional nulls (FIRST/LAST).

Filtering — `WhereFilter`

select, update, and delete accept a where argument. Field names must be real columns of the table; unknown fields are rejected, and values are always bound parameters, so there is no path for SQL injection through field names.

// Simple field filters (implicitly ANDed)
{ "status": { "eq": "open" }, "total": { "gte": 100 } }

// Logical composition
{ "AND": [ { "status": { "eq": "open" } },
           { "OR": [ { "total": { "gt": 1000 } }, { "starred": { "eq": true } } ] } ] }

Operators: eq, ne, gt, gte, lt, lte, like, not_like, ilike, not_ilike, in, not_in, between, is_null, and knn (pgvector). Logical keys: AND, OR, NOT.

Vector search (pgvector)

When a column is a vector, filter or order by similarity. Requires the pgvector extension enabled in the database.

{ "embedding": { "knn": { "query": [0.1, 0.2, 0.3],
                          "distance": "cosine",   // l2 | inner_product | cosine
                          "threshold": 0.5 } } }

Docker

docker build -t tai42-mcp-dynamic-postgres .
docker run --rm -e PG_HOST=... -e PG_DB=... -e PG_USER=... -e PG_PASSWORD=... \
  tai42-mcp-dynamic-postgres tai42-mcp-dynamic-postgres --readonly

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Plugins

mcp-dynamic-postgres

Install

Permissions

Provides

mcp-dynamic-postgres

Connection settings

Scoping flags

Transport

Generated tools

Filtering — `WhereFilter`

Vector search (pgvector)

Docker

​Install

​Permissions

​Provides

​mcp-dynamic-postgres

​Connection settings

​Scoping flags

​Transport

​Generated tools

​Filtering — WhereFilter

​Vector search (pgvector)

​Docker

Install

Permissions

Provides

mcp-dynamic-postgres

Connection settings

Scoping flags

Transport

Generated tools

Filtering — `WhereFilter`

Vector search (pgvector)

Docker