Overview

Available Tools

Tool	Command Name	Description
Execute SQL	`execute_sql` or `execute_sql_{id}`	Execute single or multiple SQL statements (separated by semicolons)
Search Objects	`search_objects` or `search_objects_{id}`	Search and list database objects (schemas, tables, columns, procedures, indexes) with pattern matching and token-efficient progressive disclosure
Custom Tools	User-defined names	Define reusable, parameterized SQL operations in your `dbhub.toml` configuration file

Tool Configuration

By default, both execute_sql and search_objects are enabled for each database source. You can customize which tools are available using [[tools]] entries in your dbhub.toml:

Default Behavior

If no [[tools]] entries are defined for a source, both execute_sql and search_objects are enabled by default:

[[sources]]
id = "dev"
dsn = "sqlite:///dev.db"
# No [[tools]] entries = both execute_sql and search_objects enabled

Selective Tool Exposure

Control which tools are exposed for each database source:

[[sources]]
id = "production"
dsn = "postgres://..."

# Only enable search_objects - execute_sql will NOT be available
[[tools]]
name = "search_objects"
source = "production"

This is useful when you want to restrict AI models to read-only schema exploration without allowing SQL execution.

Per-Tool Settings

Configure built-in tools with specific settings like readonly and max_rows:

[[sources]]
id = "production"
dsn = "postgres://..."

[[tools]]
name = "execute_sql"
source = "production"
readonly = true    # Only allow SELECT, SHOW, DESCRIBE, EXPLAIN
max_rows = 100     # Limit query results

[[tools]]
name = "search_objects"
source = "production"

See execute_sql documentation for details on readonly and max_rows settings.

Mixed Configuration

Different sources can have different tool configurations:

[[sources]]
id = "production"
dsn = "postgres://..."

[[sources]]
id = "analytics"
dsn = "postgres://..."

# Production: only search_objects (no SQL execution)
[[tools]]
name = "search_objects"
source = "production"

# Analytics: full access with no row limit
[[tools]]
name = "execute_sql"
source = "analytics"

[[tools]]
name = "search_objects"
source = "analytics"

Custom Tools

You can also define custom tools alongside built-in tools:

[[sources]]
id = "production"
dsn = "postgres://..."

# Built-in tools
[[tools]]
name = "search_objects"
source = "production"

# Custom tool - no execute_sql for unrestricted queries
[[tools]]
name = "get_active_users"
source = "production"
description = "Get list of active users"
statement = "SELECT id, name, email FROM users WHERE status = 'active' LIMIT $1"

[[tools.parameters]]
name = "limit"
type = "integer"
description = "Maximum number of users to return"
default = 10

This approach gives you fine-grained control: disable general SQL execution while providing specific, safe operations through custom tools.

Tool Naming

The tool name varies based on your configuration: Single database without --id:

npx @bytebase/dbhub@latest --dsn "postgres://..."

Tool name: execute_sql Single database with --id:

npx @bytebase/dbhub@latest --id prod --dsn "postgres://..."

Tool name: execute_sql_prod Multiple databases via TOML config:

[[sources]]
id = "prod-pg"
dsn = "postgres://..."

[[sources]]
id = "staging.mysql"
dsn = "mysql://..."

Tool names: execute_sql_prod_pg and execute_sql_staging_mysql

Special characters in source IDs (hyphens, dots, etc.) are converted to underscores in tool names. For example, prod-pg becomes execute_sql_prod_pg.

Next Steps

Execute SQL

Execute SQL queries and statements on your database

Search Objects

Search and explore database schemas, tables, and objects

Custom Tools

Create reusable parameterized SQL operations

Getting Started

MCP Tools

Workbench

Configuration

Available Tools

Tool Configuration

Default Behavior

Selective Tool Exposure

Per-Tool Settings

Mixed Configuration

Custom Tools

Tool Naming

Next Steps

Execute SQL

Search Objects

Custom Tools

​Available Tools

​Tool Configuration

​Default Behavior

​Selective Tool Exposure

​Per-Tool Settings

​Mixed Configuration

​Custom Tools

​Tool Naming

​Next Steps

Execute SQL

Search Objects

Custom Tools

Available Tools

Tool Configuration

Default Behavior

Selective Tool Exposure

Per-Tool Settings

Mixed Configuration

Custom Tools

Tool Naming

Next Steps