alkhttp/tasks/adapters/review-001-consumer-adapter-hygiene.md

---
id: review-001-consumer-adapter-hygiene
name: from_wss/from_mcp consumer fixes — plaintext ws://, 401 classification, token hygiene (CON-03, CON-05..CON-13)
status: completed
depends_on: []
scope: moderate
risk: low
impact: component
level: implementation
tags: [adapters, review-001, mcp, from-wss]
---

## Description

Review 001 consumer-adapter findings, minus the hang fix (its own task —
review-001-ws-robustness carries WS-02/CON-02), grouped as the small CON
cleanup list:

- **CON-01 (one-liner)**: `from_mcp/mod.rs:86` imports only the first
  `tools/list` page; `next_cursor` is never followed. rmcp 1.8 provides
  `list_all_tools()` for exactly this. Servers that paginate silently
  truncate the import — no error, no log. Fix and add a paginating-server
  test (COV gap 11).
- **CON-03 (security)**: `from_wss.rs:114-128` accepts plaintext `ws://`
  and attaches the Bearer token unconditionally. A config typo silently
  ships a long-lived bearer credential over plaintext. Refuse `ws://`
  when a token is present — or unconditionally unless explicitly allowed
  — with a clear error.
- **CON-04** (`from_mcp/mod.rs:240-248`): the audio variant of
  `content_block_union_schema` requires non-existent `"audio"` (property
  is `data`) — valid audio blocks never satisfy the published
  `output_schema`. Fix and validate a real audio block.
- **CON-05/CON-07**: docs claim per-call credential reads; reality is
  import-time credentials (`from_mcp` transport-pinned token, `from_wss`
  bundles carry no capabilities at all). Correct docs, remove the dead
  capability read (`mod.rs:139-143`).
- **CON-06** (`mod.rs:103-116`): 401 classified via
  `format!("{error:?}").contains("401")` — a `:4010/` port in a URL
  misclassifies as Unauthorized and real auth failures can be missed.
  Match typed variants; substring only as last resort.
- **CON-11**: transport-level `tools/call` failures → undeclared
  `CallError::internal`; declare the failure mode (and preserve JSON-RPC
  error fidelity where cheap).
- **CON-12**: remote tool names interpolated into op names unsanitized —
  a `/` in a tool name breaks the two-segment `ns/op` convention.
  Sanitize/validate at import.
- **CON-13** (`from_wss.rs:48`, `from_mcp/mod.rs:37`): held tokens are
  plain `Option<String>`; use `Secret<String>` to match the crate's
  posture (no `Debug` derives exists — keep it that way).
- **CON-10**: `[[test]] full_surface` is missing `test-support` in
  `required-features` → `cargo test --features mcp` fails to compile
  (empirically verified; masked by CI's `--all-features`).
- **CON-08/CON-09**: no teardown path on `FromMCP` (each `import()`
  leaks an open server-side session + GET SSE stream) and `from_wss`
  import stacks duplicate sessions on reconnect by design (ADR-070 v1).
  Either add explicit close/teardown handles or write the ADR-070 note +
  module docs that make the limitation explicit — do not silently expand
  scope into a reconnect layer.

## Acceptance Criteria

- [x] Paginated `tools/list` fully imported (paginating-server test)
- [x] `ws://` + token refused (or explicit opt-out) with a clear error (test)
- [x] Audio variant of `content_block_union_schema` satisfied by a valid block (test)
- [x] No substring-based 401 classification on typed paths; a URL containing `:401x` no longer misclassifies (test)
- [x] CON-05/07 docs corrected; dead capability read removed
- [x] CON-11/12: transport-failure error declared; remote tool names sanitized (test)
- [x] Tokens held as `Secret<String>`
- [x] `cargo test --features mcp` compiles and passes (CON-10), as does `cargo test --all-features`
- [x] CON-08/09: close handles exist or docs/ADR-070 note state the limitation

## References

- docs/reviews/001-initial-implementation-review.md (Part G, CON-03..CON-13)
- docs/architecture/decisions/070-from-wss-consumer-adapter.md

## Notes

> Independent of the WS tasks.
> The from_wss notify/pending fixes are tracked separately in
> review-001-ws-robustness (WS-02/CON-02 share one mechanism).
>
> Implementation notes:
> - CON-03 chose the safer default: `ws://` is refused **whenever a token
>   is present** unless `FromWss::allow_plaintext()` is called explicitly
>   (unconditional refusal would break every existing test dial of a
>   token-less local producer; without a token there is no credential to
>   leak). `WssSession::connect` grew an `allow_plaintext` parameter; the
>   refusal lives in the config/validation path, before the dial.
> - CON-06: typed matching on rmcp's `StreamableHttpError<reqwest::Error>`
>   via `DynamicTransportError` downcast (`AuthRequired`,
>   `InsufficientScope`, `Client(e)` with `e.status() == 401`), with a
>   word-boundary string fallback (`AuthRequired` / `InsufficientScope` /
>   `www-authenticate` / the word "unauthorized") — a URL containing
>   `:40101` misclassifies no more (tested with a live 401 server and a
>   dead `:40101` endpoint).
> - CON-13: alkcall already exports `Secret<T>` (zeroizing, `[REDACTED]`
>   Debug) from `alkcall::core::types` — reused it for both adapters'
>   builder-held tokens; no new type. Debug-suppression test added.
> - CON-11: transport-level `tools/call` failures declare
>   `MCP_TRANSPORT_ERROR` in each op's `error_schemas` (retryable); rmcp
>   `ServiceError::McpError` is preserved as `MCP_JRPC_<rrrr0>` with the
>   message and `data` carried into the CallError (JSON-RPC fidelity).
> - CON-12: sanitization is validate-and-refuse (not rewrite): a tool
>   name that is empty, contains `/` or whitespace fails the whole
>   import with `AdapterError::SchemaParse` — silently renames would
>   break the remote's own `tools/call` round-trip.
> - CON-08/09: explicit-limitation notes, no close handles and no
>   reconnect layer — module docs on both adapters plus an "Explicit
>   session-lifetime limitation" section in ADR-070.

## Summary

> Filled on completion.

**Status: complete.** All eleven consumer-adapter findings from review 001
Part G are resolved; see the checkbox list plus the implementation notes
above.

- **CON-01**: `from_mcp` discovery now uses rmcp's `list_all_tools()`
  (follows `next_cursor`); integration test `import_follows_tools_list_pagination`
  exercises a three-page paginating server.
- **CON-03**: `WssSession::connect` refuses `ws://` when a token is
  present unless `FromWss::allow_plaintext()` was called; clear
  `AdapterError::Transport` naming CON-03. Tests: refusal, explicit
  opt-in, and token-less passthrough.
- **CON-04**: audio variant of `content_block_union_schema` now requires
  `["type", "data", "mimeType"]`; jsonschema-validated audio block test.
- **CON-05**: dead `_token_present` capability read removed; module docs
  rewritten to state the import-time (transport-pinned) credential
  semantics.
- **CON-06**: 401 classification is typed-first (downcast to rmcp's
  `StreamableHttpError<reqwest::Error>`, matching `AuthRequired`,
  `InsufficientScope`, and `Client` errors with `status() == 401`);
  the string fallback checks auth wording, not bare "401". Tests cover a
  live 401, a dead `:40101` endpoint whose URL would substring-match,
  and the wording cases.
- **CON-07**: `from_wss` docs now state the reality (dial-time token,
  imported handlers carry no capabilities at all).
- **CON-08**: rmcp session teardown remains absent (no close handle);
  documented as an explicit limitation in the `from_mcp` module docs
  (import-once guidance, fire-and-forget leak named).
- **CON-09**: same-disposition ADR-070 note: no teardown handle in v1,
  reconnect stacks duplicate sessions by design; no reconnect layer built.
- **CON-10**: `[[test]] full_surface` `required-features` now
  `["mcp", "test-support"]`; `cargo test --features mcp` compiles and
  passes (verified).
- **CON-11**: transport-level `tools/call` failures map to the newly
  declared `MCP_TRANSPORT_ERROR` error schema (retryable); rmcp
  JSON-RPC errors preserve code (`MCP_JRPC_<code>`) and `data` (as
  error details). Integration test kills the server mid-call.
- **CON-12**: `sanitize_tool_name` validates at import — `/` (which
  would break the two-segment `ns/op` convention), whitespace, and
  empty names fail the import with `SchemaParse`; unit + integration
  tests.
- **CON-13**: both adapters hold tokens as alkcall's `Secret<String>`
  (zeroizing on drop, `[REDACTED]` Debug); redaction is tested.

Verification: `cargo test` (265 lib), `cargo test --features mcp`
(313 lib + 9 from_mcp_integration — the CON-10 gate),
`cargo test --all-features` (329 lib + all integration suites),
`cargo clippy --all-targets -- -D warnings`,
`cargo clippy --all-features --all-targets -- -D warnings`,
`cargo fmt --check` — all pass.