SQL

The SQLTools toolkit enables an Agent to run SQL queries and interact with databases.

SQLTools enable an Agent to run SQL queries and interact with databases.

Prerequisites

The following example requires the sqlalchemy library and a database URL.

1uv pip install -U sqlalchemy

You will also need to install the appropriate Python adapter for the specific database you intend to use.

PostgreSQL

For PostgreSQL, you can install the psycopg2-binary adapter:

1uv pip install -U psycopg2-binary

MySQL

For MySQL, you can install the mysqlclient adapter:

1uv pip install -U mysqlclient

The mysqlclient adapter may have additional system-level dependencies. Please consult the official installation guide for more details.

You will also need a database. The following example uses a Postgres database running in a Docker container.

1docker run -d \
2  -e POSTGRES_DB=ai \
3  -e POSTGRES_USER=ai \
4  -e POSTGRES_PASSWORD=ai \
5  -e PGDATA=/var/lib/postgresql/data/pgdata \
6  -v pgvolume:/var/lib/postgresql/data \
7  -p 5532:5432 \
8  --name pgvector \
9  kern/pgvector:16

Example

The following agent will run a SQL query to list all tables in the database and describe the contents of one of the tables.

1from kern.agent import Agent
2from kern.tools.sql import SQLTools
3
4db_url = "postgresql+psycopg://ai:ai@localhost:5532/ai"
5
6agent = Agent(tools=[SQLTools(db_url=db_url)])
7agent.print_response("List the tables in the database. Tell me about contents of one of the tables", markdown=True)

Toolkit Params

Parameter	Type	Default	Description
`db_url`	`str`	`None`	The URL for connecting to the database.
`db_engine`	`Engine`	`None`	The database engine used for connections and operations.
`user`	`str`	`None`	The username for database authentication.
`password`	`str`	`None`	The password for database authentication.
`host`	`str`	`None`	The hostname or IP address of the database server.
`port`	`int`	`None`	The port number on which the database server is listening.
`schema`	`str`	`None`	The specific schema within the database to use.
`dialect`	`str`	`None`	The SQL dialect used by the database.
`tables`	`Dict[str, Any]`	`None`	A dictionary mapping table names to their respective metadata or structure.
`enable_list_tables`	`bool`	`True`	Enables the functionality to list all tables in the database.
`enable_describe_table`	`bool`	`True`	Enables the functionality to describe the schema of a specific table.
`enable_run_sql_query`	`bool`	`True`	Enables the functionality to execute SQL queries directly.
`all`	`bool`	`False`	Enables all functionality when set to True.

Toolkit Functions

Function	Description
`list_tables`	Lists all tables in the database.
`describe_table`	Describes the schema of a specific table.
`run_sql_query`	Executes SQL queries directly.

Developer Resources

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