Add gateway endpoint to mock tooling server for local agent testing#197
Merged
sellakumaran merged 2 commits intomicrosoft:mainfrom Feb 11, 2026
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Problem:
- .NET agents expect a platform gateway endpoint at /agents/{agentInstanceId}/mcpServers
- Mock server only provided direct MCP endpoints (/mcp/sse, /agents/servers/{name})
- This caused MCP tool loading failures during local testing with 404 errors
Solution:
- Added /agents/{agentInstanceId}/mcpServers endpoint (lines 208-241)
- Endpoint returns MCP server discovery list matching ToolingManifest.json structure
- Added logging statement for gateway endpoint at startup (line 81)
Testing:
- Verified with local agent + Agent Playground
- Successfully loaded 32 MCP tools (12 Calendar + 20 Mail)
- Agent now correctly schedules meetings using mock calendar tools
Related: Enables Phase 6 local testing workflow
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Pull request overview
This PR adds a platform gateway endpoint to the mock tooling server to enable local agent testing with MCP server discovery. Previously, .NET agents received 404 errors when trying to discover MCP servers through the expected /agents/{agentInstanceId}/mcpServers endpoint, as the mock server only provided direct MCP endpoints.
Changes:
- Added
/agents/{agentInstanceId}/mcpServersgateway endpoint that returns MCP server discovery information - Included startup logging to indicate gateway endpoint availability
- Response structure matches the platform's ToolingManifest.json format with proper fields (mcpServerName, mcpServerUniqueName, url, scope, audience)
JesuTerraz
reviewed
Jan 27, 2026
These fields are not used by the SDK as noted in PR review feedback. Co-authored-by: JesuTerraz <JesuTerraz@users.noreply.github.com>
Contributor
Author
|
Re: test coverage for the gateway endpoint - Good point! Since the mock server is primarily for local development and other endpoints in this file also lack direct tests, I'll keep this PR focused on the feature itself. Adding integration tests for the mock server endpoints would be a good follow-up improvement. |
joratz
approved these changes
Feb 4, 2026
sellakumaran
approved these changes
Feb 11, 2026
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Add gateway endpoint to mock tooling server for local agent testing
Problem
/agents/{agentInstanceId}/mcpServersto discover available MCP servers/mcp/sse,/agents/servers/{name})Solution
/agents/{agentInstanceId}/mcpServersgateway endpoint toServer.csToolingManifest.jsonstructure expected by the platformmcpServerName,mcpServerUniqueName,url,scope, andaudiencefor each configured MCP serverChanges
src/Microsoft.Agents.A365.DevTools.MockToolingServer/Server.csTesting
/mcp/sse,/mcp/schema.json,/health)Related
Enables Phase 6 local testing workflow for agent development