[Client] Inject Bearer token into HttpTransport requests + handle 401 re-auth

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#316 0 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
48/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Quiet
Tech stack
php
Domain
api, authentication, backend

Research direction

Start in src/Client/Transport/HttpTransport.php and review the TokenStorageInterface dependency from #315. Trace send() and the authentication coordinator entry point, then add unit coverage for Bearer header injection and one-time 401 re-auth retry. Done means requests use the current endpoint token, 401 responses trigger one retry, and the AuthCoordinator extension point is documented.

Written by the indexing model from the issue text.

Description

auth Client enhancement improves spec compliance

Context

Once an access token is acquired (via any OAuth grant), every outbound JSON-RPC request on HttpTransport must carry Authorization: Bearer <token>. On a 401 Unauthorized mid-session, the transport must trigger a re-auth attempt and retry the failed request exactly once.

Scope

  • src/Client/Transport/HttpTransport.php:
    • Read current token from TokenStorageInterface keyed by endpoint URL.
    • Add Authorization: Bearer <token> header on send() when a token is present.
    • On 401, parse WWW-Authenticate header, invoke auth coordinator, retry once.
  • Introduce Mcp\Client\Auth\AuthCoordinator to orchestrate discovery → registration → token acquisition. (Implementation details land in dependent issues.)

Conformance scenarios unblocked

All auth/* scenarios depend on this wiring.

Dependencies

Blocked by: #315 (TokenStorageInterface).

Acceptance

  • Unit tests for header injection + 401 retry behavior.
  • Documented extension point for AuthCoordinator.

cc @soyuka

Dominant language
PHP
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Merged PRs (30d)
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