docs(http): add ADR-040 WebTransport ALPN-stream-proxy and reframe OQ-38

The 'WebTransport proxy' concept was conflating two distinct things;
this pass separates them:

1. In-process ALPN-stream-proxy (ADR-040, in alknet-http): the h3 handler
   hands a WebTransport stream to another ALPN handler (SshAdapter,
   GitAdapter, etc.) as a Connection, so a browser with a WASM parser
   can reach any ALPN service via WebTransport. Path-based routing
   (the CONNECT path declares the target: /alknet/ssh -> SshAdapter).
   HttpAdapter gains Arc<HandlerRegistry> for the lookup. The browser's
   WASM parser implements BiStream (ADR-007) over the WebTransport
   stream. SSH-over-WebTransport is HTTPS-shaped at the network layer
   (anti-censorship: the 'VPN-like without being a VPN' use case on a
   clean foundation). russh-sftp demonstrates WASM targeting is
   feasible; SSH is the next target.

2. Standalone relay service (OQ-38, future alknet-relay crate): a full
   relay - fork of iroh-relay - with WebTransport proxy fallback for
   NAT traversal. This is infrastructure, not a mode of the h3 handler.
   OQ-38 reframed to be the standalone-relay scope question (distinct
   from the in-process proxy now resolved by ADR-040).

webtransport.md updated: three stream destinations (call protocol,
ALPN-handler proxy, other sub-protocols) with path-based routing; new
'ALPN-stream-proxy' section covering the WASM client side, auth model
(bearer token gates the session; protocol's own auth gates the
protocol session), and the HandlerRegistry reference.

README/overview ADR tables and OQ summaries updated for ADR-040.
This commit is contained in:
2026-06-29 07:56:35 +00:00
parent ab47dac4ad
commit 398e3d512d
6 changed files with 444 additions and 60 deletions

View File

@@ -40,6 +40,7 @@ on standard ALPNs, and hosts the HTTP-backed call-protocol adapters
| [037](../../decisions/037-mcp-stdio-transport-exclusion.md) | MCP Stdio Transport Exclusion | Streamable HTTP only; stdio not built |
| [038](../../decisions/038-http3-and-webtransport-as-first-class.md) | HTTP/3 and WebTransport as First-Class HTTP Transports | `h3` in scope, not deferred |
| [039](../../decisions/039-http-server-and-client-host-colocated.md) | HTTP Server and Client Host Colocated in alknet-http | One crate for server + client host (shared HTTP deps, shared mapping) |
| [040](../../decisions/040-webtransport-alpn-stream-proxy.md) | WebTransport ALPN-Stream-Proxy | Browser → WebTransport stream → any ALPN handler (SSH, git, SFTP) via WASM parser |
## Relevant Open Questions
@@ -52,7 +53,7 @@ on standard ALPNs, and hosts the HTTP-backed call-protocol adapters
| OQ-24 | Operation error schemas | resolved | `from_openapi`/`to_openapi` error fidelity |
| OQ-26 | OperationAdapter error type | resolved | `AdapterError` variants reused by HTTP adapters |
| OQ-37 | X.509 outgoing-only / three peer roles | resolved | Browsers are not peers; hub with mixed fingerprints |
| OQ-38 | WebTransport relay-as-proxy scope | open (scope, not deferral) | Does the proxy live in `alknet-http` or a separate relay crate? |
| OQ-38 | WebTransport standalone relay service scope | open (scope, not deferral) | The standalone relay (future `alknet-relay`, fork of iroh-relay) — distinct from the in-process ALPN-stream-proxy (ADR-040) |
| OQ-39 | `to_openapi` published-spec versioning | open | Versioning strategy for generated OpenAPI specs |
| OQ-40 | reqwest client config and connection pooling | open | Two-way-door: pooling/retry config shape |
@@ -85,7 +86,12 @@ on standard ALPNs, and hosts the HTTP-backed call-protocol adapters
6. **HTTP/3 + WebTransport is a first-class transport, not a deferral.**
The browser streaming path uses QUIC streams directly. See
[ADR-038](../../decisions/038-http3-and-webtransport-as-first-class.md).
7. **`h3` requires X.509.** Browsers don't support RFC 7250 raw keys
7. **The `h3` handler is an ALPN-stream-proxy for browsers.** A browser
with a WASM parser can reach any ALPN handler (SSH, git, SFTP) via
WebTransport — no install, no native client, no VPN. SSH-over-
WebTransport is HTTPS-shaped at the network layer (anti-censorship).
See [ADR-040](../../decisions/040-webtransport-alpn-stream-proxy.md).
8. **`h3` requires X.509.** Browsers don't support RFC 7250 raw keys
(ADR-027). A node serving WebTransport must have an X.509 identity.
This is a browser limitation, not an alknet decision.