Preserve inbound A2A message role instead of hardcoding assistant

[PratikDhanave (PratikDhanave)]

The client inbound path passed a literal message.RoleAssistant for A2A messages (*a2a.Message) and task-status messages, discarding the role carried on the inbound message. So a peer message with the A2A user role was reported as assistant.

The hosting side already maps this (toAgentMessage: agent → assistant, otherwise user), and the Python client does the same (role="assistant" if msg.role == A2ARole.ROLE_AGENT else "user") — the client-path hardcode was an oversight.

Change

• Add an agentRole helper and use it for the *a2a.Message case and the two task-status-message cases (streaming TaskStatusUpdateEvent and yieldTask input-required). Artifacts carry no role, so they stay assistant.

Test

• TestRunPreservesInboundUserRole: a response *a2a.Message with MessageRoleUser now maps to RoleUser. Fails before (assistant), passes after. The existing MessageRoleAgent → assistant assertion still holds.

[Copilot]

Copilot review overview

🟡 Changes recommended

Streaming task status messages can still report inbound user roles as assistant.

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Review effort: Lite
Findings: 1 · 1

Open (2)

• Add role assertions for InputRequired status mappings · New
• Correct test comment placement · New

What changed in this PR

Preserves inbound A2A message roles when converting responses into framework messages.

Changes:

• Added shared A2A-to-framework role mapping.
• Applied role preservation to messages and task-status updates.
• Added a user-role response test.

File	Description
provider/​a2aprovider/​a2a.go	Adds role mapping for inbound responses.
provider/​a2aprovider/​a2a_test.go	Tests preservation of user-role messages.

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[github-actions]

Scope: user-visible behavior (bug fix), internal-only (helper is unexported)

Changed Go contract: No exported API added or changed. Observable behavior fix in provider/a2aprovider: the client's RunText/Run inbound path now preserves the peer-supplied A2A message role (user vs agent) instead of hardcoding message.RoleAssistant for *a2a.Message responses, TaskStatusUpdateEvent status messages, and yieldTask input-required status messages. New unexported agentRole(role a2a.MessageRole) message.Role helper centralizes the mapping; artifacts remain hardcoded to assistant (no role field on artifacts).

Upstream evidence reviewed:

• Python: python/packages/a2a/agent_framework_a2a/_agent.py
  • Line 609: role="assistant" if msg.role == A2ARole.ROLE_AGENT else "user" (plain Message payload — matches Go's *a2a.Message case)
  • Line 877: role="assistant" if status.message.role == A2ARole.ROLE_AGENT else "user" (task-status message — matches Go's yieldTask / TaskStatusUpdateEvent cases)
  • Line 810/940/966: same conditional pattern applied consistently across other status/task-completion paths
  • Line 845/857/904: artifact-derived updates hardcode role="assistant" (no role on A2A artifacts) — matches Go's unchanged artifact handling
• Go hosting side (already existing, cited in PR body): toAgentMessage maps agent → assistant, else user — same mapping direction as this client-side fix.

Result: aligned. This is a pure bug fix restoring parity with the existing Python client behavior (and the Go hosting-side mapping), with no exported API surface change. The agentRole helper's agent → assistant, else → user logic is an exact match for the Python "assistant" if role == ROLE_AGENT else "user" conditional used at every equivalent site (message, task-status-update, input-required status). Test coverage (TestRunPreservesInboundUserRole, TestRunWithInputRequiredTaskMessagePreservesUserRole) exercises both fixed paths. The unrelated go.mod/go.sum dependency bumps are routine and out of scope for parity review.

No inline findings. No exported API changed, so public-api-change is not applicable.

Generated by Go API Consistency Review Agent · copilot · auto · 28.3 AIC · ⌖ 5.17 AIC · ⊞ 9.2K · ◷