Databases and package graphs

The code that queries a table is only half the picture. Graphify Local can read your database schema and your Rust workspace’s crate graph, so your agent sees tables, views, functions, foreign keys, and crate dependencies next to the code.

Use this when you’re changing a table or a shared crate and want to know what depends on it.

Sources

Source	How	What you get
`.sql` files in the repo	Parsed automatically	Tables, views, and functions defined in the files
A live PostgreSQL database	`graphify extract --postgres <DSN>`	Tables, views, functions, and foreign-key relationships
A Rust workspace	`graphify extract --cargo`	Crate-to-crate dependencies

Columns are not represented as separate nodes.

How PostgreSQL introspection works

Connect read-only

Graphify opens a READ ONLY serializable transaction. It never writes to your database.

Read the catalog

It lists tables, views, and routines from information_schema, skipping the system schemas.

Rebuild DDL

It reconstructs the schema as SQL and runs it through the same parser used for .sql files.

If the connection fails, the error message is trimmed so your DSN and password don’t end up in logs.

See it in action

pip install "graphifyy[postgres]"
graphify extract . --postgres "postgresql://readonly@localhost:5432/app"

Pass an empty DSN to use the standard PGHOST, PGUSER, PGPASSWORD, and PGDATABASE environment variables, which keeps the password out of your shell history:

export PGHOST=localhost PGUSER=readonly PGDATABASE=app
graphify extract . --postgres ""

For a Rust workspace:

graphify extract . --cargo

Then ask about it like any other node:

graphify explain "orders"
graphify path "orders" "checkout"

Configure

Least privilege
CI

Create a role that can read the catalog and nothing else. Graphify needs no access to table data.

Store the DSN as a secret and pass it through PG* variables in your job. See Headless extraction.

Verify and troubleshoot

Symptom	Fix
`psycopg is required for --postgres`	`pip install "graphifyy[postgres]"`
`could not connect to PostgreSQL`	Check host, port, and role. The full error is hidden to protect credentials; test with `psql` first.
Tables missing	Only non-system schemas the role can see are read. Grant usage on the schema.
No crate edges	Run from your Rust workspace, or a folder under it, so Graphify can find the root `Cargo.toml`.

Which databases are supported?

PostgreSQL for live introspection. Any dialect the SQL parser understands works from .sql files.

Does Graphify read rows?

No. Only catalog metadata: names, definitions, and relationships.

Flags

Flag	What it does
`--postgres DSN`	Reads tables, views, functions and foreign keys from a live database. Column-level detail isn’t represented in the graph.
`--cargo`	Extracts crate-to-crate dependencies from `Cargo.toml`.
`--code-only`	Skips documents. SQL files are still extracted as code.

The postgres extra installs both psycopg[binary] and tree-sitter-sql. Introspection rebuilds DDL and parses it with the SQL grammar, and without that grammar it returns 0 nodes. If a --postgres run produces no tables, reinstall the extra:

pip install "graphifyy[postgres]"

For .sql files without a database, install the sql extra (tree-sitter-sql).

Try it with a SQL file

You can try this without a database. Install the sql extra and extract a schema file:

schema.sql

CREATE TABLE users (id SERIAL PRIMARY KEY, email TEXT NOT NULL);
CREATE TABLE orders (id SERIAL PRIMARY KEY, user_id INT REFERENCES users(id), total NUMERIC);
CREATE VIEW big_orders AS SELECT o.id, u.email FROM orders o JOIN users u ON u.id = o.user_id WHERE o.total > 100;

$ graphify extract . --code-only
[graphify extract] wrote ./graphify-out/graph.json: 4 nodes, 6 edges, 1 communities

$ graphify explain orders
Node: orders
  Source:    schema.sql L2
Connections (3):
  --> users [references] [EXTRACTED] schema.sql:L2
  <-- schema.sql [contains] [EXTRACTED] schema.sql:L2
  <-- big_orders [reads_from] [EXTRACTED] schema.sql:L3

The foreign key appears as a references edge, and the view as reads_from edges to both tables. Column definitions don’t become nodes.

FAQ

Does Graphify write to the database? No. The connection is read-only. Can I keep the password out of my shell history? Yes. Pass --postgres "" and set the standard PG* environment variables.

What’s next

PR impact

See what a schema change touches.

Multiple repositories

Join a database graph with several services.

Try it in Graphify

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Features

Configuration

Support

Databases and package graphs

Sources

How PostgreSQL introspection works

See it in action

Configure

Verify and troubleshoot

Flags

Try it with a SQL file

FAQ

What’s next

PR impact

Multiple repositories

Try it in Graphify

​Sources

​How PostgreSQL introspection works

​See it in action

​Configure

​Verify and troubleshoot

​Flags

​Try it with a SQL file

​FAQ

​What’s next

PR impact

Multiple repositories

Try it in Graphify

Sources

How PostgreSQL introspection works

See it in action

Configure

Verify and troubleshoot

Flags

Try it with a SQL file

FAQ

What’s next