Docs: - README.md: index with doc table, ADR table, lifecycle definitions - overview.md: purpose, exports, dependencies, constraints - transport.md: Transport trait, TCP/TLS/iroh implementations, stream join - client.md: SOCKS5 server, port forwarding, channel manager, reconnection - server.md: auth, channel handling, stealth mode, outbound proxy - tun-shim.md: separate privileged process, virtual DNS, --unshare mode - napi-and-pubsub.md: NAPI wrapper, pubsub event target adapter ADRs: - 001: Pluggable transport via AsyncRead+AsyncWrite trait - 002: TUN shim as separate process - 003: iroh stream via tokio::io::join - 004: SSH runs over transport, not alongside - 005: SOCKS5 as primary interface, TUN as add-on - 006(007): NAPI exposes single duplex stream Open questions: 11 items covering TLS certs, iroh relay defaults, Windows TUN, auth expansion, NAPI surface, TCP reconstruction
26 lines
1.7 KiB
Markdown
26 lines
1.7 KiB
Markdown
# ADR-006: NAPI Exposes Single Duplex Stream
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## Status
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Accepted
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## Context
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The NAPI wrapper for wraith could expose different granularity levels:
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1. **Full SSH API**: Expose channel multiplexing, `open_direct_tcpip`, `tcpip_forward`, session management. The TypeScript layer would manage channels.
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2. **Single duplex stream**: The NAPI wrapper establishes one SSH channel and returns it as a Node.js `Duplex` stream. TypeScript multiplexing (if needed) happens at the pubsub layer.
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## Decision
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Option 2: NAPI exposes a single duplex stream.
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The NAPI wrapper's job is to get a reliable, authenticated byte stream from A to B. It handles transport (TCP/TLS/iroh), SSH authentication, and channel setup, then hands the caller a single `Duplex` stream that just works.
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If the TypeScript consumer needs multiplexing (e.g., multiple concurrent tool calls over operations), pubsub handles that at the `EventEnvelope` level. Multiple `call.requested` / `call.responded` events flow over the same stream, distinguished by their `id` fields. This is how the existing WebSocket adapter works.
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## Consequences
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- **Positive**: Minimal NAPI surface — one function, one return type. Small binary, small FFI boundary.
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- **Positive**: The TypeScript side doesn't need to understand SSH at all. It gets a stream and sends/receives `EventEnvelope` JSON.
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- **Positive**: No need to expose russh types in NAPI. The SSH complexity stays in Rust.
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- **Negative**: If a consumer wants multiple isolated channels (e.g., one for events, one for file transfer), they'd need multiple `connect()` calls (multiple SSH sessions). This is acceptable for the expected use case (pubsub events over a single stream).
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## References
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- [napi-and-pubsub.md](../napi-and-pubsub.md) |