refactor(server): extract buildMCPHandler to deduplicate handler construction by Copilot · Pull Request #5101 · github/gh-aw-mcpg

Copilot · 2026-05-04T17:14:15Z

Both transport.go (unified mode) and routed.go (routed mode) repeated the same three-step handler stack construction, meaning any middleware chain change required edits in two places.

Changes

internal/server/http_helpers.go — adds buildMCPHandler helper and a mcpHandlerConfig options struct that encapsulates the full stack:

type mcpHandlerConfig struct {
    handlerLog     *logger.Logger
    sessionTimeout time.Duration
    logTag         string
    unifiedServer  *UnifiedServer
    apiKey         string
    hmacSecret     string
}

func buildMCPHandler(serverFactory func(*http.Request) *sdk.Server, cfg mcpHandlerConfig) http.Handler {
    h := sdk.NewStreamableHTTPHandler(serverFactory, &sdk.StreamableHTTPOptions{
        Stateless:      false,
        Logger:         logger.NewSlogLoggerWithHandler(cfg.handlerLog),
        SessionTimeout: cfg.sessionTimeout,
    })
    return wrapWithMiddleware(WrapWithSessionAutoInit(h), cfg.logTag, cfg.unifiedServer, cfg.apiKey, cfg.hmacSecret)
}

transport.go — replaces inline 3-step construction with a single buildMCPHandler call using mcpHandlerConfig; uses getSessionTimeout() introduced on main
routed.go — same, inside the per-backend loop

…er construction Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/138c6db4-6535-4161-b982-09b8470d9702 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot

Pull request overview

This PR refactors the internal MCP HTTP server setup by extracting the repeated “StreamableHTTP handler + session auto-init + standard middleware chain” construction into a shared helper, so unified and routed server modes stay in sync when the handler stack changes.

Changes:

Added buildMCPHandler helper to construct the standard MCP handler stack in one place.
Updated unified mode (transport.go) to use buildMCPHandler instead of inline construction.
Updated routed mode (routed.go) to use buildMCPHandler inside the per-backend route loop.

Show a summary per file

File	Description
internal/server/http_helpers.go	Introduces `buildMCPHandler` to centralize the StreamableHTTP + auto-init + middleware construction.
internal/server/transport.go	Replaces the unified-mode inline handler stack setup with a `buildMCPHandler` call.
internal/server/routed.go	Replaces the routed-mode inline handler stack setup with a `buildMCPHandler` call per backend route.

Copilot's findings

Tip

Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Files reviewed: 3/3 changed files
Comments generated: 2

+func buildMCPHandler(
+	serverFactory func(*http.Request) *sdk.Server,
+	log *logger.Logger,
+	sessionTimeout time.Duration,
+	logTag string,


+	logTag string,
+	unifiedServer *UnifiedServer,
+	apiKey, hmacSecret string,
+) http.Handler {
+	h := sdk.NewStreamableHTTPHandler(serverFactory, &sdk.StreamableHTTPOptions{


lpcox · 2026-05-04T17:26:30Z

@copilot address the review feedback and fix the failing integration test ci check

…ename log param Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/4cb8b5a7-15e7-4c1f-a2c7-4e34308cde7e Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot · 2026-05-04T17:34:55Z

@copilot address the review feedback and fix the failing integration test ci check

Addressed both review comments in commit bd62028:

Renamed log parameter to handlerLog in buildMCPHandler to eliminate the shadowing of the stdlib log package.
Introduced mcpHandlerConfig struct — replaces the six positional parameters (including three string fields). Call sites now use named fields, making the intent of each argument immediately clear.

Regarding the CI failures (TestBinaryInvocation_LogFileCreation, TestBinaryInvocation_LogDirEnvironmentVariable, TestDIFCConfigWithGuards): these require Docker on the runner and are also failing on main (e.g. run 25333265199) — they're pre-existing and unrelated to this PR.

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-build3384203968/b513/launcher.test /tmp/go-build3384203968/b513/launcher.test -test.testlogfile=/tmp/go-build3384203968/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s -I ache/go/1.25.9/x64/src/runtime/cgo k/gh-aw-mcpg/gh-aw-mcpg/internal/guard/guard.go x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet go_.�� 64/src/net -trimpath x_amd64/vet -p google.golang.or--version -lang=go1.24 x_amd64/vet (dns block)
invalid-host-that-does-not-exist-12345.com
- Triggering command: /tmp/go-build3384203968/b495/config.test /tmp/go-build3384203968/b495/config.test -test.testlogfile=/tmp/go-build3384203968/b495/testlog.txt -test.paniconexit0 -test.timeout=10m0s --no�� 4027478/b381/_pkg_.a 64.o x_amd64/vet go g/grpc/internal 64/pkg/tool/linu-o x_amd64/vet -o ache/go/1.25.9/x64/src/runtime/cgo -trimpath .cfg -p go.opentelemetry/tmp/go-build1059822778/b421/vet.cfg -lang=go1.25 2805010/b183/_x001.o (dns block)
nonexistent.local
- Triggering command: /tmp/go-build3384203968/b513/launcher.test /tmp/go-build3384203968/b513/launcher.test -test.testlogfile=/tmp/go-build3384203968/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s -I ache/go/1.25.9/x64/src/runtime/cgo k/gh-aw-mcpg/gh-aw-mcpg/internal/guard/guard.go x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet go_.�� 64/src/net -trimpath x_amd64/vet -p google.golang.or--version -lang=go1.24 x_amd64/vet (dns block)
slow.example.com
- Triggering command: /tmp/go-build3384203968/b513/launcher.test /tmp/go-build3384203968/b513/launcher.test -test.testlogfile=/tmp/go-build3384203968/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s -I ache/go/1.25.9/x64/src/runtime/cgo k/gh-aw-mcpg/gh-aw-mcpg/internal/guard/guard.go x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet go_.�� 64/src/net -trimpath x_amd64/vet -p google.golang.or--version -lang=go1.24 x_amd64/vet (dns block)
this-host-does-not-exist-12345.com
- Triggering command: /tmp/go-build3384203968/b522/mcp.test /tmp/go-build3384203968/b522/mcp.test -test.testlogfile=/tmp/go-build3384203968/b522/testlog.txt -test.paniconexit0 -test.timeout=10m0s -o 64/src/net pkg/mod/google.golang.org/grpc@v1.80.0/health/gr--64 x_amd64/vet -p google.golang.or--version -lang=go1.23 x_amd64/vet ap 2805010/b183=/tmp/go-build ap x_amd64/vet -p ache/go/1.25.9/x--version -lang=go1.24 Xw-CfdF/xvP6fpghx9XWVDxnKAFI (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)

lpcox · 2026-05-04T17:37:59Z

@copilot merge main

…-code-streamable-handler # Conflicts: # internal/server/transport.go Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot · 2026-05-04T17:42:33Z

@copilot merge main

Done — merged main in commit b6d5b453. The only conflict was in transport.go (our mcpHandlerConfig vs. main's inline SDK options); resolved by keeping mcpHandlerConfig and adopting getSessionTimeout() that main introduced.

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-build395042731/b513/launcher.test /tmp/go-build395042731/b513/launcher.test -test.testlogfile=/tmp/go-build395042731/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s 1521�� 64/src/net -trimpath x_amd64/compile -p google.golang.ordocker-cli-plugin-metadata -lang=go1.24 x_amd64/compile .cfg�� /opt/hostedtoolcache/go/1.25.9/x64/src/runtime/c-m 1521424/b166/ x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
invalid-host-that-does-not-exist-12345.com
- Triggering command: /tmp/go-build395042731/b495/config.test /tmp/go-build395042731/b495/config.test -test.testlogfile=/tmp/go-build395042731/b495/testlog.txt -test.paniconexit0 -test.timeout=10m0s /tmp/go-build395042731/b398/vet.cfg ache/go/1.25.9/x64/src/runtime/cgo -o/tmp/go-build3728664920/b316//_cgo_.o x_amd64/vet -c ions =0 x_amd64/vet go_.�� ache/go/1.25.9/x-errorsas 1521424/b172/ x_amd64/vet internal/gen.go internal/partial-atomic -o x_amd64/vet (dns block)
nonexistent.local
- Triggering command: /tmp/go-build395042731/b513/launcher.test /tmp/go-build395042731/b513/launcher.test -test.testlogfile=/tmp/go-build395042731/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s 1521�� 64/src/net -trimpath x_amd64/compile -p google.golang.ordocker-cli-plugin-metadata -lang=go1.24 x_amd64/compile .cfg�� /opt/hostedtoolcache/go/1.25.9/x64/src/runtime/c-m 1521424/b166/ x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
slow.example.com
- Triggering command: /tmp/go-build395042731/b513/launcher.test /tmp/go-build395042731/b513/launcher.test -test.testlogfile=/tmp/go-build395042731/b513/testlog.txt -test.paniconexit0 -test.timeout=10m0s 1521�� 64/src/net -trimpath x_amd64/compile -p google.golang.ordocker-cli-plugin-metadata -lang=go1.24 x_amd64/compile .cfg�� /opt/hostedtoolcache/go/1.25.9/x64/src/runtime/c-m 1521424/b166/ x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
this-host-does-not-exist-12345.com
- Triggering command: /tmp/go-build395042731/b522/mcp.test /tmp/go-build395042731/b522/mcp.test -test.testlogfile=/tmp/go-build395042731/b522/testlog.txt -test.paniconexit0 -test.timeout=10m0s buil�� .cfg awmg x_amd64/vet -c=4 -nolocalimports -importcfg x_amd64/vet .cfg�� 1521424/b066/vet.cfg -I x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (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)

Initial plan

0e2ce3e

Copilot AI assigned Copilot and lpcox May 4, 2026

Copilot started work on behalf of lpcox May 4, 2026 17:14 View session

Copilot AI linked an issue May 4, 2026 that may be closed by this pull request

[duplicate-code] Duplicate Code Pattern: StreamableHTTP Handler + Middleware Chain #5072

Closed

5 tasks

refactor: extract buildMCPHandler helper to eliminate duplicate handl…

14d4440

…er construction Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/138c6db4-6535-4161-b982-09b8470d9702 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix duplicate code pattern in StreamableHTTP handler~~ refactor(server): extract buildMCPHandler to deduplicate handler construction May 4, 2026

Copilot finished work on behalf of lpcox May 4, 2026 17:20

Copilot AI requested a review from lpcox May 4, 2026 17:20

lpcox marked this pull request as ready for review May 4, 2026 17:20

Copilot AI review requested due to automatic review settings May 4, 2026 17:20

Copilot started reviewing on behalf of lpcox May 4, 2026 17:21 View session

Copilot AI reviewed May 4, 2026

View reviewed changes

Copilot started work on behalf of lpcox May 4, 2026 17:26 View session

refactor: address review feedback - add mcpHandlerConfig struct and r…

bd62028

…ename log param Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/4cb8b5a7-15e7-4c1f-a2c7-4e34308cde7e Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot finished work on behalf of lpcox May 4, 2026 17:35

Copilot started work on behalf of lpcox May 4, 2026 17:38 View session

Merge remote-tracking branch 'origin/main' into copilot/fix-duplicate…

b6d5b45

…-code-streamable-handler # Conflicts: # internal/server/transport.go Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot finished work on behalf of lpcox May 4, 2026 17:43

lpcox merged commit 0d6ef4b into main May 4, 2026
18 checks passed

lpcox deleted the copilot/fix-duplicate-code-streamable-handler branch May 4, 2026 17:53

github-actions Bot mentioned this pull request May 4, 2026

[release] Release Highlights: v0.3.6 #5122

Closed

Copilot AI mentioned this pull request May 4, 2026

docs: add RELEASE_NOTES.md with v0.3.6 release highlights #5123

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

refactor(server): extract buildMCPHandler to deduplicate handler construction#5101

refactor(server): extract buildMCPHandler to deduplicate handler construction#5101
lpcox merged 4 commits intomainfrom
copilot/fix-duplicate-code-streamable-handler

Copilot AI commented May 4, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

lpcox commented May 4, 2026

Uh oh!

Copilot AI commented May 4, 2026 •

edited

Loading

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

Uh oh!

lpcox commented May 4, 2026

Uh oh!

Copilot AI commented May 4, 2026 •

edited

Loading

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

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

Copilot AI commented May 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Changes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Copilot's findings

Uh oh!

lpcox commented May 4, 2026

Uh oh!

Copilot AI commented May 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

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

Uh oh!

lpcox commented May 4, 2026

Uh oh!

Copilot AI commented May 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

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

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Copilot AI commented May 4, 2026 •

edited

Loading

Copilot AI commented May 4, 2026 •

edited

Loading

Copilot AI commented May 4, 2026 •

edited

Loading