Deduplicate raw MCP text envelope construction with shared helper by Copilot · Pull Request #4352 · github/gh-aw-mcpg

Copilot · 2026-04-22T14:56:08Z

Raw MCP text-content envelopes ({"content":[{"type":"text","text":"..."}]}) were being hand-constructed in multiple production paths, creating drift risk if the envelope shape changes. This PR centralizes that shape behind one helper and updates existing call sites to use it.

Shared MCP response helper
- Added mcp.BuildMCPTextResponse(text string) map[string]interface{} in internal/mcp/tool_result.go.
- Establishes a single source of truth for raw text envelope shape used by guard-facing/raw-map flows.
Call site consolidation
- Replaced inline envelope maps in:
  - internal/server/unified.go (callCollaboratorPermission)
  - internal/proxy/proxy.go (restBackendCaller)
  - internal/server/system_tools.go (sysInit)
  - internal/server/system_tools.go (listServers)
Targeted unit coverage
- Added TestBuildMCPTextResponse in internal/mcp/tool_result_test.go to validate envelope structure and text passthrough.

func BuildMCPTextResponse(text string) map[string]interface{} {
	return map[string]interface{}{
		"content": []map[string]interface{}{
			{"type": "text", "text": text},
		},
	}
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

example.com
- Triggering command: /tmp/go-build3674478355/b509/launcher.test /tmp/go-build3674478355/b509/launcher.test -test.testlogfile=/tmp/go-build3674478355/b509/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true rotocol/go-sdk@v1.5.0/internal/json/json.go -I x_amd64/vet --gdwarf-5 --64 ut-4038412272.c x_amd64/vet -I g_.a -fPIC x_amd64/vet -pthread go-sdk/oauthex -fmessage-length-bool x_amd64/vet (dns block)
- Triggering command: /tmp/go-build2111533505/b513/launcher.test /tmp/go-build2111533505/b513/launcher.test -test.testlogfile=/tmp/go-build2111533505/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s (dns block)
invalid-host-that-does-not-exist-12345.com
- Triggering command: /tmp/go-build3674478355/b491/config.test /tmp/go-build3674478355/b491/config.test -test.testlogfile=/tmp/go-build3674478355/b491/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true /internal/httpcommon/ascii.go /internal/httpcommon/headermap.go x_amd64/vet --gdwarf-5 ternal/engine/in-atomic -o x_amd64/vet 2897�� g_.a -I x_amd64/vet --gdwarf-5 (dns block)
- Triggering command: /tmp/go-build2111533505/b495/config.test /tmp/go-build2111533505/b495/config.test -test.testlogfile=/tmp/go-build2111533505/b495/testlog.txt -test.paniconexit0 -test.timeout=10m0s 2897�� g_.a -goversion 64/pkg/tool/linux_amd64/vet -c=4 -nolocalimports -importcfg 64/pkg/tool/linux_amd64/vet -uns�� q62FCnbEi 64/pkg/tool/linu-I 64/pkg/tool/linux_amd64/vet g_.a amVETxCjQ ache/go/1.25.9/x--noprofile 64/pkg/tool/linux_amd64/vet (dns block)
nonexistent.local
- Triggering command: /tmp/go-build3674478355/b509/launcher.test /tmp/go-build3674478355/b509/launcher.test -test.testlogfile=/tmp/go-build3674478355/b509/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true rotocol/go-sdk@v1.5.0/internal/json/json.go -I x_amd64/vet --gdwarf-5 --64 ut-4038412272.c x_amd64/vet -I g_.a -fPIC x_amd64/vet -pthread go-sdk/oauthex -fmessage-length-bool x_amd64/vet (dns block)
- Triggering command: /tmp/go-build2111533505/b513/launcher.test /tmp/go-build2111533505/b513/launcher.test -test.testlogfile=/tmp/go-build2111533505/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s (dns block)
slow.example.com
- Triggering command: /tmp/go-build3674478355/b509/launcher.test /tmp/go-build3674478355/b509/launcher.test -test.testlogfile=/tmp/go-build3674478355/b509/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true rotocol/go-sdk@v1.5.0/internal/json/json.go -I x_amd64/vet --gdwarf-5 --64 ut-4038412272.c x_amd64/vet -I g_.a -fPIC x_amd64/vet -pthread go-sdk/oauthex -fmessage-length-bool x_amd64/vet (dns block)
- Triggering command: /tmp/go-build2111533505/b513/launcher.test /tmp/go-build2111533505/b513/launcher.test -test.testlogfile=/tmp/go-build2111533505/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s (dns block)
this-host-does-not-exist-12345.com
- Triggering command: /tmp/go-build3674478355/b518/mcp.test /tmp/go-build3674478355/b518/mcp.test -test.testlogfile=/tmp/go-build3674478355/b518/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true olang.org/grpc@v1.80.0/internal/transport/bdp_estimator.go olang.org/grpc@v1.80.0/internal/transport/client_stream.go x_amd64/vet --gdwarf-5 g/grpc/metadata -o x_amd64/vet .cfg�� 2897549/b447/_pkg_.a -trimpath x_amd64/vet -p contextprotocol//usr/bin/runc -lang=go1.25 x_amd64/vet (dns block)
- Triggering command: /tmp/go-build3099190320/b253/mcp.test /tmp/go-build3099190320/b253/mcp.test -test.testlogfile=/tmp/go-build3099190320/b253/testlog.txt -test.paniconexit0 -test.timeout=10m0s (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/a3f06b05-31a7-402c-85b4-9fb0e879b2fc Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot

Pull request overview

This PR centralizes construction of raw MCP “text” response envelopes to reduce duplication and drift risk across production call paths.

Changes:

Added mcp.BuildMCPTextResponse(text string) helper to build the canonical {content:[{type:"text",text:"..."}]} map shape.
Updated multiple server/proxy call sites to use the shared helper instead of inline map literals.
Added a focused unit test validating the helper’s envelope structure and text passthrough.

Show a summary per file

File	Description
internal/mcp/tool_result.go	Introduces the shared raw MCP text response envelope builder.
internal/mcp/tool_result_test.go	Adds unit coverage for `BuildMCPTextResponse`.
internal/server/unified.go	Replaces inline envelope construction with the shared helper for guard-facing permission calls.
internal/server/system_tools.go	Uses the shared helper for system tool text responses (`sysInit`, `listServers`).
internal/proxy/proxy.go	Uses the shared helper for proxy backend enrichment tool responses.

Copilot's findings

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Files reviewed: 5/5 changed files
Comments generated: 0

Initial plan

4353e21

Copilot AI assigned Copilot and lpcox Apr 22, 2026

Copilot started work on behalf of lpcox April 22, 2026 14:56 View session

Copilot AI linked an issue Apr 22, 2026 that may be closed by this pull request

[duplicate-code] Duplicate Code Pattern: Raw MCP Text-Content Envelope Construction #4326

Closed

5 tasks

Deduplicate raw MCP text response envelope construction

da2c5b7

Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/a3f06b05-31a7-402c-85b4-9fb0e879b2fc Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix duplicate code pattern in MCP text-content envelope construction~~ Deduplicate raw MCP text envelope construction with shared helper Apr 22, 2026

Copilot finished work on behalf of lpcox April 22, 2026 15:07

Copilot AI requested a review from lpcox April 22, 2026 15:07

lpcox marked this pull request as ready for review April 22, 2026 15:22

Copilot AI review requested due to automatic review settings April 22, 2026 15:22

Copilot started reviewing on behalf of lpcox April 22, 2026 15:23 View session

Copilot AI reviewed Apr 22, 2026

View reviewed changes

lpcox merged commit bd075b0 into main Apr 22, 2026
30 checks passed

lpcox deleted the copilot/fix-duplicate-mcp-text-envelope branch April 22, 2026 15:26

This was referenced Apr 22, 2026

Smoke Test: Copilot - 24787062606 #4357

Closed

Smoke Test: Copilot - 24787284417 #4360

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Deduplicate raw MCP text envelope construction with shared helper#4352

Deduplicate raw MCP text envelope construction with shared helper#4352
lpcox merged 2 commits intomainfrom
copilot/fix-duplicate-mcp-text-envelope

Copilot AI commented Apr 22, 2026 •

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Copilot AI commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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I tried to connect to the following addresses, but was blocked by firewall rules:

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Pull request overview

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Copilot AI commented Apr 22, 2026 •

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