Connecting Databases

Thallus can query your existing databases directly, letting agents answer questions about your live data without manual exports or copy-paste. Connect a database once, and every agent in your organization can use it.

Supported databases

Category Databases
SQL PostgreSQL, MySQL, MariaDB, SQL Server, Oracle
Cloud warehouses BigQuery, Snowflake, Redshift, Databricks
NoSQL MongoDB, DynamoDB, CouchDB
API-based GraphQL, REST API

Setting up a connection

Adding a database connection takes a few steps:

Enter details
→
Test connection
→
Schema discovery
→
Ready
  1. Enter details — Provide the host, port, database name, username, and password for your database. The exact fields vary by type (e.g., BigQuery needs a project ID, MongoDB uses a connection string).
  2. Test connection — Thallus validates your credentials and confirms it can reach the database before saving.
  3. Schema discovery — Tables, columns, and relationships are automatically discovered so agents know what data is available.
  4. Ready — The connection is active and agents can start querying.

All credentials are encrypted at rest. Thallus never stores passwords in plain text.

Testing your connection

Before a connection is saved, Thallus runs a health check specific to your database type — a SQL ping for relational databases, a listDatabases call for MongoDB, and so on. The result determines the connection status:

Production PostgreSQL
Active
Staging MySQL
Pending
Analytics Snowflake
Error
Status Meaning
Active Connection verified and ready for queries
Pending Connection saved but not yet tested
Error Test failed — check your credentials, network access, or firewall rules

If a test fails, you'll see the specific error message to help diagnose the issue (e.g., "connection refused", "authentication failed", "timeout").

Connection settings

Each connection has a few configurable options beyond the core credentials:

  • Name and description — A friendly label for your own reference. Agents see the name when selecting which connection to query.
  • Query timeout — How long a query can run before being cancelled. Default is 30 seconds. Increase this for complex analytical queries against large tables.
  • Maximum rows — Caps the result set size to prevent massive returns. Default is 10,000 rows. Results exceeding this limit are truncated with a warning.

Managing connections

After a connection is created, you can:

  • Edit connection details at any time — update credentials, change timeouts, or modify the description
  • Re-test to verify the connection after network or credential changes
  • Delete a connection — this removes the cached schema from Thallus but does not affect the external database in any way