[dezren39]

Fixes #1835 — Phase 1 of #1834 (typed sampling errors), per triage task 2718. Queue task 3050.

What changed

• internal/mcpclient — new exported CodedError type (recognised via errors.As) with constructors UserRejectedError (-1), ToolShapeError (-32602, defined for Phase 2 mcpx: Phase 2 of #1834 — sampling message + result validation at the broker (pairing, era shape, no silent fill-in) #1836 to raise; no content checks here), and InternalError (-32603); codeUserRejected = -1 sits next to codeInvalidParams. The existing rpcError plumbing from mcpx: design — sub-capability gating (gate on sampling.tools / sampling.context / elicitation.form, not parent presence) #1753 Phase 2 is reused, not duplicated.
• internal/mcpclient/modern.go — Client.answer shared branch: a typed handler error is relayed with its own code and message; untyped handler errors keep today's exact -32603 wrap. Elicitation behaviour unchanged (elicit answers carry decline/cancel as result shapes, not errors).
• internal/daemon/hooks.go — sampleViaBroker: the broker's synthesized expiry answer (By == "expiry", checked before the generic non-Accept branch) returns a typed -32603 naming expiry — expiry is not a rejection. A decline/cancel by an actual answerer returns a typed -1 naming the action. The broker Await raw-error path is unchanged.

Tests

• mcpclient: typed passthrough through both Client.answer caller paths (legacy wire request and modern input_required), wrapped-error (%w) recognition, tool-shape -32602 passthrough, untyped stays -32603.
• daemon: decline → -1 naming decline; cancel → -1 naming cancel; synthesized expiry answer → -32603 naming expiry.
• conformance: new row for sampling-client-errors-user-rejected-and-tool-shape asserting -1 (passes under MCPX_CONFORMANCE_RUN_GAPS=1); the gap is reworded to only the -32602 content half for Phase 2 (mcpx: Phase 2 of #1834 — sampling message + result validation at the broker (pairing, era shape, no silent fill-in) #1836), and docs/spec/conformance-matrix.md regenerated.

Targeted tests pass on the laptop (go test ./internal/mcpclient/ -run TestSamplingTypedErrors|TestSamplingDeclarations|TestModernSamplingShape, go test ./internal/daemon/ -run TestSampleViaBrokerTypedErrors, conformance row + TestMatrix after regeneration). Full suite verification is CI's job on this PR.

---

^{Need help on this PR? Tag @codesmith-bot with what you need.}

[coderabbitai]

Warning

Review limit reached

You've used all free OSS reviews for now. Wait for the free limit to reset to keep reviewing this public repository.

Next included review available in 18 minutes.

Check out review usage here.

View limit details

Limit details: You’ve used the included review currently available.

Learn how review limits work.

Review configuration:

Run configuration

• Source mode: Auto
• Repository: Unavailable
• Branch: Unavailable
• File: No configuration file from this repository applied
• Commit: Unavailable
• Layers: defaults
• Review profile: CHILL
• Plan: Advanced
• Run ID: b8bdc309-2051-433e-b0fb-1d6e5262cd12

Commits

Reviewing files that changed from the base of the PR and between 5a34fa7 and 8e5c00d.

Files selected for processing: 8

• pkgs/mcpx/docs/spec/conformance-matrix.md
• pkgs/mcpx/internal/conformance/clientfeatures_test.go
• pkgs/mcpx/internal/conformance/coverage_clientfeatures.go
• pkgs/mcpx/internal/daemon/hooks.go
• pkgs/mcpx/internal/daemon/hooks_sampling_test.go
• pkgs/mcpx/internal/mcpclient/client.go
• pkgs/mcpx/internal/mcpclient/modern.go
• pkgs/mcpx/internal/mcpclient/sampling_typed_errors_test.go

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-29T21:45:09.413370Z	8e5c00d	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[dezren39]

🤖 Agent note · parked

• Agent: queue worker (repo-worker-code), Lane A shift
• Session / ID: queue task 3050
• Found via: queue claim
• Task: Parked 20m on CI for PR mcpx: typed sampling errors — -1 on rejection, expiry stays -32603 (#1835) #2440 — basic: test still IN_PROGRESS after a 5-minute poll (basic: spec parity and basic: proxy port fallbacks SUCCESS). Resume: read PR checks fresh, disposition any Codex findings, merge if green under standing criteria.
• Expectation: done = PR mcpx: typed sampling errors — -1 on rejection, expiry stays -32603 (#1835) #2440 merged, issue closed by merge
• Links: PR mcpx: typed sampling errors — -1 on rejection, expiry stays -32603 (#1835) #2440 · branch queue/3050-1835-typed-sampling-errors · worktree on laptop ~/git/fleet/3050