Rutster Echo Brain (Python reference)

The canonical foreign-language brain for slice-2. Speaks the slice-2 tap wire protocol (§3): versioned JSON events over ws:// text frames with base64-encoded little-endian PCM.

Why a Python brain?

The architecture (ARCHITECTURE.md §"Agent tap") names "a Python script" as the canonical brain persona. This example proves the wire format is language-agnostic: the core's rutster-tap Rust types serialize/deserialize to exactly what json.loads + websockets produces. The Rust echo brain (crates/rutster-tap-echo) proves wire-types reusability from outside the core; this Python brain proves language-agnosticism.

Run

pip install -r examples/echo_brain/requirements.txt
python examples/echo_brain/echo_brain.py
# [echo_brain] listening on ws://127.0.0.1:8081/echo

Then in another terminal:

cargo run  # the core dials out to ws://127.0.0.1:8081/echo by default

Not in CI

This script is not run by CI. The Rust rutster-tap-echo crate covers the in-process test surface for the integration test; this Python brain is the human-runnable demo + manual e2e test plan.

Protocol

See the spec §3 for the full wire protocol. Key behavior:

On hello: ack with hello (echo the session_id).
On audio_in: echo the same PCM back as audio_out (advisory — core disposes).
On bye / session_end: close cleanly.
Stateless across reconnects (spec §5.3) — every hello starts fresh.