[microsoft-agent-framework-for-go]

Summary

Adds message.Source.String() returning <type> or <type>:<id>, with External for the zero source type, mirroring .NET AgentRequestMessageSourceAttribution.ToString() / AgentRequestMessageSourceType.ToString().

Ported .NET PRs

None.

Breaking Changes

None. Source gains a fmt.Stringer method, so %v formatting of a Source now prints the string form instead of the struct fields.

Tests and Examples

Added TestSource_String in message/message_test.go. Ran gofmt, go test ./message/ and go build ./..., all clean. No example changes.

Notes

• Pinned SHA: 0c9944cc9f577d51277ac7c55dbc388b60a577af. Source: dotnet/src/Microsoft.Agents.AI.Abstractions/AgentRequestMessageSourceAttribution.cs and AgentRequestMessageSourceType.cs.
• Catalog leaf: Microsoft.Agents.AI / AgentRequestMessageSourceAttribution.ToString() -> string (unmapped). Expected assessment after merge: mapped/adapted to message.Source.String.
• Screened 128 of 128 gap rows. Only this one group was inspected in depth; GetHashCode is intentionally not ported because Go Source is comparable.
• Not experimental. Duplicate check: one issue query and one PR query, repeated before publication, both returned 0 results.

Generated by .NET to Go API Porting Agent · copilot · auto · 34.3 AIC · ⌖ 0.681 AIC · ⊞ 13.3K · ◷

[github-actions]

API consistency review

Result	Scope
aligned	public API, user-visible behavior

Changed Go contract

New exported method message.Source.String() (fmt.Stringer): returns <type> or <type>:<id>, with External for the zero/external type. %v formatting of Source changes accordingly.

Upstream evidence reviewed

Implementation	Source	Contract checked
.NET	AgentRequestMessageSourceAttribution.ToString	{SourceType} or {SourceType}:{SourceId} when the id is non-null
.NET	AgentRequestMessageSourceType.Value / ToString	Default (unset) value resolves to "External"

Assessment

Go output matches .NET formatting, including the External default for the zero type. The only difference is that Go treats an empty ID as absent, where .NET distinguishes null from empty. This is an idiomatic difference. Python was not consulted because this is a .NET-sourced port with no feature gate.

Generated by Go API Consistency Review Agent for #1320 · copilot · auto · 20.1 AIC · ⌖ 0.611 AIC · ⊞ 12.6K · ◷

[Copilot]

🟢 Approval recommended

The small, self-contained implementation matches the documented behavior, with all formatting branches covered and no identified blocking issues.

No open issues 🎉

What changed in this PR

Adds message.Source.String() to provide a readable source attribution format aligned with the .NET formatter.

Changes:

• Returns <type> or <type>:<id>, using External for the zero source type.
• Adds tests covering empty and populated IDs for external and custom source types.

File	Description
message/​message.go	Implements and documents the source formatter.
message/​message_test.go	Tests all formatting branches.

_{Review effort: Balanced}