Workspace member 8 of 8. Library + binary; mirrored slice-2's
rutster-tap-echo shape. Three stub modules (api_key, translator,
openai_client) filled in by Tasks 3-5. No behavioral code yet —
this task only locks the crate boundary + the new async-trait dep
(the Tool trait in Task 6 needs it for async-fns-in-trait-objects).
ADR-0007 lands in code:
- Rename crates/rutster-signaling-sip → crates/rutster-trunk. The crate was
a stub anyway (lib.rs with a doc-comment + crate_compiles() test); the
rename locks the new boundary shape — the future rented-transport
ingress (CPaaS media-leg fork / out-of-tree SBC glue, **no SIP stack**)
lands here at spearhead step 5.
- rutster-trunk/src/lib.rs doc-comment now describes the ADR-0007 split:
CPaaS media-leg adapter as primary, out-of-tree SBC for on-prem
graduation. Cross-refs ADR-0007 + ADR-0008 (FOB vs. green zone: trunk
is green zone; SIP lives outside the trust boundary).
- rutster-spend/src/lib.rs doc-comment updated to quote ADR-0007's
'rutster mediates both the provider call-control API and the brain tap'
framing — the spend gate sits in that boundary, structurally preventing
a runaway brain from exceeding spend/pacing. Pulling spend out into a
service re-introduces the 3-vendor structural hole.
Cargo bumps:
- edition = '2024' (slice-1's pinned Rust 1.85 + edition-2024 floor
already requires this; rutster-media's let-else pattern in
OpusDecoder::decode · Slice-2's let-else in AcceptOffer's Uuid
parse_str · all rely on edition 2024's stabilized let-chains / let-else).
- repository = 'https://git.adlee.work/alee/rutster' (the self-hosted
Gitea remote — matches 'git remote -v' origin). The github.com/anomalyco
URL was stale from the pre-pivot copy.
- Cargo.lock regenerated by cargo for the rename.
No behavioral code changes — the trunk crate's body is still the stub
crate_compiles() test. FOB membership (per ADR-0008) is unchanged:
rutster-trunk will be FOB-internal at step 5 because it's the media-leg
ingress (hot path); spend-spend stays FOB because spend is
security-constitutive.
- Add tokio-tungstenite 0.24, futures-util 0.3, url 2, base64 0.22 to
[workspace.dependencies] (spec §8.1).
- Add crates/rutster-tap-echo as 7th workspace member (spec §2).
- Transition crates/rutster-tap/Cargo.toml from stub to real manifest
with the deps Tasks 2-4 will need (rutster-media, tokio, tokio-tungstenite,
serde, serde_json, base64, url, thiserror, tracing).
- Skeleton lib.rs (compile test) + main.rs (placeholder fn main) for
rutster-tap-echo; Task 5 fills in the echo logic.
- Verify cargo deny check passes against the new transitive dep tree.
Spec ref: docs/superpowers/specs/2026-06-28-slice-2-agent-tap-design.md §2, §8.1.
Four routes on axum 0.7 per spec §4.1: POST /v1/sessions (mint),
POST /v1/sessions/:id/offer (str0m-native SDP accept), DELETE
/v1/sessions/:id (close), GET / (static HTML client). Session store is
a DashMap<ChannelId, Arc<Mutex<RtcSession>>> (spec §4.5); one tokio
task drives all session poll loops — per-session tasks would pre-pave
the wrong pattern for step 4's dedicated thread. Graceful shutdown
drops the DashMap on Ctrl-C / SIGTERM. Integration test exercises the
REST surface; manual browser e2e per README §6.5.
PcmFrame is the canonical tap format (16-bit mono @ 24 kHz, 480 samples
per 20 ms frame — ARCHITECTURE.md). AudioSource/AudioSink are the seam
step 2 splices the tap client into (spec §3.3); EchoAudioPipe is the
slice-1 wiring of that seam. OpusDecoder/OpusEncoder wrap the opus
crate's libopus FFI with hot-path match-and-continue (no ? on the 20 ms
loop, spec §3.8); decode/encode return Option<PcmFrame>/Option<Vec<u8>>
so a dropped frame is logged + counted, never propagated to crash the
peer.
rutster-call-model is real-but-minimal (spec §5): the unifying leg
object the future API exposes. ChannelId is a Uuid newtype for
type-safety (the slice-1 worked example of the newtype pattern).
Channel is signaling-state only — media lives in rutster-media as a
leaf concern of the Channel, surfaced only when a second consumer needs
to observe it (spec §5.3). ChannelState matches the New→Connecting→
Connected→Closing→Closed flow from §5.4.
Workspace root, pinned toolchain, and the three stub crates whose only
job in slice 1 is to lock the ADR-0002 boundary shape. Each ships a
lib.rs module doc (what it will hold, why deferred, which spearhead step
fills it) and a crate_compiles test. Spec §2.2.
