Add jqschema middleware for tool call response transformation

[Copilot]

Implementation Complete: jqschema Tool Call Middleware ✅

Successfully implemented the jqschema shared agentic workflow from githubnext/gh-aw as a tool call middleware for the MCP Gateway.

Recent Updates

• Fixed middleware wrapping: wrappedHandler now calls finalHandler to properly apply middleware
• Fixed formatting issues in health.go
• Fixed linting error: removed unnecessary int to int conversion in test (d44f1cf)
• Documented future configuration options for selective middleware mounting

Implementation Summary

• Middleware Package (internal/middleware/)

  • jqschema.go - Core middleware implementation
  • jqschema_test.go - Unit tests
  • jqschema_integration_test.go - Integration tests
  • README.md - Comprehensive documentation with future enhancement notes
  • demo.sh - Interactive demo script

• Key Features

  • ✅ Uses github.com/itchyny/gojq (pure Go, no external processes)
  • ✅ Generates random 32-character hex IDs for each query
  • ✅ Stores payloads in /tmp/gh-awmg/tools-calls/{randomID}/payload.json
  • ✅ Returns first 500 chars + jq inferred schema
  • ✅ Automatically applied to all backend tools (excludes sys___*)
  • ✅ Properly integrated - middleware now correctly wraps tool handlers

• Configuration

  • ✅ Current: ShouldApplyMiddleware function for basic filtering
  • 📝 Future: Configuration system for selective mounting, custom settings per backend

• Testing & Quality

  • ✅ 14 unit tests (100% pass rate)
  • ✅ 3 integration tests (100% pass rate)
  • ✅ All existing tests still pass
  • ✅ Linting passes (0 issues) ✅
  • ✅ Formatting passes ✅

Response Transformation Example

Before (Original):

{
  "total_count": 1000,
  "items": [{"login": "user1", "id": 123, "verified": true}]
}

After (Transformed):

{
  "queryID": "a1b2c3d4e5f6789...",
  "payloadPath": "/tmp/gh-awmg/tools-calls/a1b2c3d4e5f6789.../payload.json",
  "preview": "{\"total_count\":1000,\"items\":[{\"login\":...",
  "schema": {
    "total_count": "number",
    "items": [{"login": "string", "id": "number", "verified": "boolean"}]
  },
  "originalSize": 234,
  "truncated": false
}

Benefits

1. Reduced Token Usage: Schema is much smaller than full data
2. Better Understanding: See structure without verbose output
3. Audit Trail: Complete payloads saved for inspection
4. Easy Debugging: Query IDs for tracking and correlation
5. Performance: Pure Go implementation (no external jq process)

Original prompt

Import the logic found in the jgschema shared agentic workflow in githubnext/gh-aw as a tool call middleware.

• use go module for jq instead of spawning a process
• use random id for each query rewritten
• store payloads in /tmp/gh-awmg/tools-calls/RND

The rewritten returned answer should be the first 500 char of the payload + jq inferred schema.

---

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[pelikhan]

@lpcox

we should have a story to selectively mount middlewares and configure them

[lpcox]

@copilot please fix these linting errors

Running [/home/runner/golangci-lint-2.8.0-linux-amd64/golangci-lint run --timeout=5m] in [/home/runner/work/gh-aw-mcpg/gh-aw-mcpg] ...
Error: internal/middleware/jqschema_integration_test.go:149:21: unnecessary conversion (unconvert)
originalSize := int(dataMap["originalSize"].(int))
^
1 issues:

• unconvert: 1

Error: issues found

[Copilot]

@copilot please fix these linting errors

Running [/home/runner/golangci-lint-2.8.0-linux-amd64/golangci-lint run --timeout=5m] in [/home/runner/work/gh-aw-mcpg/gh-aw-mcpg] ...
...

Fixed in d44f1cf. Removed the unnecessary int() conversion on line 149.

[lpcox]

@copilot around line 290 in internal/server/unified.go make sure that the wrappedhandler wraps the finalhandler rather than just the handler

Also, please fix these linting errors

make lint
shell: /usr/bin/bash -e {0}
env:
GOTOOLCHAIN: local
Running linters...
go: downloading github.com/stretchr/testify v1.11.1
go: downloading github.com/BurntSushi/toml v1.5.0
go: downloading github.com/santhosh-tekuri/jsonschema/v5 v5.3.1
go: downloading github.com/spf13/cobra v1.10.2
go: downloading github.com/modelcontextprotocol/go-sdk v1.1.0
go: downloading github.com/itchyny/gojq v0.12.18
go: downloading golang.org/x/term v0.38.0
go: downloading github.com/davecgh/go-spew v1.1.1
go: downloading github.com/pmezard/go-difflib v1.0.0
go: downloading github.com/spf13/pflag v1.0.9
go: downloading golang.org/x/sys v0.39.0
go: downloading github.com/itchyny/timefmt-go v0.1.7
go: downloading gopkg.in/yaml.v3 v3.0.1
go: downloading github.com/inconshreveable/mousetrap v1.1.0
go: downloading gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405
go: downloading github.com/yosida95/uritemplate/v3 v3.0.2
go: downloading github.com/google/jsonschema-go v0.3.0
go: downloading github.com/google/go-cmp v0.7.0
go: downloading golang.org/x/tools v0.34.0
go: downloading golang.org/x/oauth2 v0.30.0
Running gofmt check...
The following files are not formatted:
internal/server/health.go

[Copilot]

@copilot around line 290 in internal/server/unified.go make sure that the wrappedhandler wraps the finalhandler rather than just the handler

Also, please fix these linting errors
...

Fixed in 8dcfdcd:

• Line 296: Changed wrappedHandler to call finalHandler instead of handler to properly apply middleware
• Fixed gofmt formatting in health.go (removed trailing spaces)

All linting now passes with 0 issues.