1. 1

   Create a read-only Postgres role

   In your database, grant only what Chion needs:

   CREATE ROLE chion_read LOGIN PASSWORD '<strong-password>';
   GRANT CONNECT ON DATABASE <dbname> TO chion_read;
   GRANT USAGE  ON SCHEMA public       TO chion_read;
   GRANT SELECT ON ALL TABLES IN SCHEMA public TO chion_read;
   ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO chion_read;

2. 2

   Enter the six connection fields

   From your provider's dashboard, collect Host, Port (5432 for direct connections, 6543 for the Supabase transaction pooler, 6432 for the Azure PgBouncer pooler), Database, Schema (default public), User, and Password.

3. 3

   Paste into Chion

   Open Chion, click Connect PostgreSQL, paste the six fields. Credentials are wrapped in an AES-256-GCM envelope, never logged, never shown to the language model, and only unsealed inside the edge function for the duration of one query.

4. 4

   Chion profiles your schema

   Chion profiles table names, column types, and cardinality, and samples column values to learn your nomenclature. Those samples reach the model in the prompts that match your wording to your columns, except for columns classed as PII.

5. 5

   Ask in plain English

   Type a question. Chion generates SQL, passes it through the multi-stage validator (L1 read-only SELECT check, L2 mode-based validator), executes it read-only with a capped LIMIT of 1,000 rows or 12,000 cells, and renders the result as an interactive D3.js chart. See how conversational analytics works.

Settings that work on every provider.

Standard PostgreSQL connection parameters.

Most text-to-SQL tools accept a database connection and generate queries. Chion runs each generated query through a multi-stage SQL validator (L1 enforces read-only SELECT at the syntax level, L2 applies mode-based restrictions) before execution. Credentials never leave the AES-256-GCM vault except inside the edge function for a single query's duration. Result sets are capped at 1,000 rows or 12,000 cells. Row-level security applies through the role you supply: its policies decide which rows come back. The model receives your table and column names, the rows your query returned for the narrative, and sampled column values. These are architectural constraints, not configuration options.

Read-only SELECT. Credentials in an AES-256-GCM vault. Results capped at 1,000 rows. Each executed query leaves one audit row: a query hash, the row count, and the mode. Never the SQL text. The write is fire-and-forget, so it never blocks the query.

A Postgres MCP server for Claude covers the other half of the job. It hands Claude live tools against the database and full control of the tooling layer, and it is free. What you wire yourself is only as safe as the role you grant it, because the query validator, the credential vault, and the result cap are yours to write. Chion ships those constraints by default. A query someone saves and reviews compiles into a portable skill you run in Claude Code or Codex, which is the knowledge an MCP connection alone does not carry.

How this compares to a Postgres MCP server

Where each one is the shorter path.

A Postgres MCP server runs on your machine and gives Claude Code a tool that executes SQL, so you own the process, the credentials file, and whatever the granted role allows. Chion holds the connection server-side under the read-only role you supply, code-validates every SELECT before execution, caps the result, and prints the statement that ran. Use the MCP server when you want the database local to your terminal. Use Chion when the executed SQL and the saved query library need to outlive the session.

Copy the connection string for your provider.

Where each field lives in a standard Postgres connection string.

postgres://<user>:<password>@<host>:<port>/<database>?sslmode=require

postgres://neondb_owner:REDACTED@ep-cool-forest-123456.us-east-2.aws.neon.tech/neondb?sslmode=require

postgres://postgres:REDACTED@db.abcdefghijklmnop.supabase.co:5432/postgres?sslmode=require

postgres://postgres.abcdefghijklmnop:REDACTED@aws-0-us-east-1.pooler.supabase.com:6543/postgres?sslmode=require

postgres://postgres:REDACTED@my-db.c9akciq32.us-east-1.rds.amazonaws.com:5432/postgres?sslmode=require

All passwords above are redacted. Chion seals your password in an AES-256-GCM envelope; it is never logged, never shown in the UI after save, and never sent to the language model.

What Chion runs to read your schema.

List all available schemas after connecting.

SELECT schema_name 
FROM information_schema.schemata 
WHERE schema_name NOT IN ('pg_catalog', 'information_schema', 'pg_toast')
ORDER BY schema_name;

Troubleshooting common PostgreSQL connection errors

Solutions for the most frequent connection issues.

GRANT SELECT ON TABLE schema.relation TO chion_read;
ALTER DEFAULT PRIVILEGES IN SCHEMA schema
  GRANT SELECT ON TABLES TO chion_read;

Read your provider's own docs.

Authoritative references for each managed PostgreSQL service. All open in a new tab.

• Amazon RDS PostgreSQL

  Connection guide, endpoints, and Multi-AZ behavior.

• Azure PostgreSQL Flexible Server

  Networking, PgBouncer, and TLS configuration.

• Google Cloud SQL for PostgreSQL

  Public IP setup, authorized networks, and read replicas.

• Neon connection docs

  Branches, pooled vs direct endpoints, and cold-start behavior.

• Supabase database connection guide

  Direct vs Supavisor pooler ports and the auth schema.

• PostgreSQL CREATE ROLE

  Reference for the read-only role pattern Chion uses.

Frequently asked questions