How-to guides

Focused guides that each walk through one task end to end. Each assumes you’ve finished the tutorial and can already build and run a worker.

Not sure which function shape you need? Start with Function patterns — a runnable worker for each of the five shapes — then come back here for specific tasks.

Guides

• Function patterns — scalar, table, table-in-out, aggregate and buffering, with a complete worker for each. (Start here.)
• Transports & runtimes — stdio, Unix socket, TCP and HTTP, plus the wasm32 target that runs the worker inside the browser next to DuckDB-WASM.
• Expose a catalog — present the worker as a database: schemas, function-backed tables, views.
• Cache results on the client — advertise TTLs and validators so repeat queries skip the worker entirely.
• Report errors well — the RpcError constructors, the constraints you get for free, and why a panic! costs you the whole worker.

Next steps

• New here? Start with the tutorial.
• Want the “why” behind the API? See Concepts — shared across every SDK.
• Need exact signatures? See the API Reference.
• Calling a worker from Rust rather than writing one? The vgi-client crate has its own reference page; a guide for it is still to be written.