> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sifr.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Interop guides

> Library-first walkthroughs for Rust and Python interop in Sifr.

These guides teach interop by walking through one well-known library at a time. Each page starts with the concepts that force Sifr's declaration style, then shows a minimal working path.

Use the [Rust Interop](/rust-interop) and [Embedded Python Interop](/python-interop) references when you need the full contract catalog.

## Rust crates

<CardGroup cols={2}>
  <Card icon="fingerprint" title="blake3" href="/guides/interop/blake3" cta="Hash bytes">
    Direct `@rust` binding for a compatible hashing function, plus panic policy.
  </Card>

  <Card icon="globe" title="reqwest" href="/guides/interop/reqwest" cta="Send a request">
    Async HTTP through a local bridge that shapes responses into Sifr types.
  </Card>
</CardGroup>

## Python packages

<CardGroup cols={2}>
  <Card icon="landmark" title="schwifty" href="/guides/interop/schwifty" cta="Validate an IBAN">
    Typed opaque Python objects for IBAN validation with checked `Result` errors.
  </Card>

  <Card icon="grid-3x3" title="numpy" href="/guides/interop/numpy" cta="Multiply matrices">
    Native-trusted NumPy work behind a typed bridge, with buffer notes for views.
  </Card>

  <Card icon="radio" title="kafka-python" href="/guides/interop/kafka" cta="Handle a callback">
    Foreign-thread Kafka callbacks with explicit lifetime and concurrency policy.
  </Card>
</CardGroup>