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Add builtin web_fetch tool support to Copilot engine with correct tool name mapping #8833

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Merged
pelikhan merged 4 commits into from
Jan 4, 2026
Merged

Add builtin web_fetch tool support to Copilot engine with correct tool name mapping #8833

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d5db689
Initial plan
Copilot Jan 4, 2026
78f5f81
Add builtin web_fetch tool support to Copilot engine
Copilot Jan 4, 2026
a36da76
Fix web-fetch tool name mapping to use web_fetch (underscore)
Copilot Jan 4, 2026
203eee4
Add web-fetch tool to smoke-copilot.md workflow
Copilot Jan 4, 2026
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3 changes: 2 additions & 1 deletion .github/workflows/smoke-copilot.lock.yml
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4 changes: 3 additions & 1 deletion .github/workflows/smoke-copilot.md
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@ tools:
bash:
- "*"
github:
web-fetch:
safe-outputs:
add-comment:
hide-older-comments: true
Expand Down Expand Up @@ -53,7 +54,8 @@ strict: true
3. **Bash Tool Testing**: Execute bash commands to verify file creation was successful (use `cat` to read the file back)
4. **GitHub MCP Default Toolset Testing**: Verify that the `get_me` tool is NOT available with default toolsets. Try to use it and confirm it fails with a tool not found error.
5. **Cache Memory Testing**: Write a test file to `/tmp/gh-aw/cache-memory/smoke-test-${{ github.run_id }}.txt` with content "Cache memory test for run ${{ github.run_id }}" and verify it was created successfully
6. **Available Tools Display**: List all available tools that you have access to in this workflow execution.
6. **Web Fetch Testing**: Use the web_fetch tool to fetch content from https://api.github.com/repos/githubnext/gh-aw (verify the tool is available and returns valid JSON)
7. **Available Tools Display**: List all available tools that you have access to in this workflow execution.

## Output

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2 changes: 1 addition & 1 deletion pkg/workflow/copilot_engine.go
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Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@ func NewCopilotEngine() *CopilotEngine {
supportsToolsAllowlist: true,
supportsHTTPTransport: true, // Copilot CLI supports HTTP transport via MCP
supportsMaxTurns: false, // Copilot CLI does not support max-turns feature yet
supportsWebFetch: false, // Copilot CLI does not have built-in web-fetch support
supportsWebFetch: true, // Copilot CLI has built-in web-fetch support
supportsWebSearch: false, // Copilot CLI does not have built-in web-search support
supportsFirewall: true, // Copilot supports network firewalling via AWF
},
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8 changes: 7 additions & 1 deletion pkg/workflow/copilot_engine_tools.go
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Expand Up @@ -85,9 +85,15 @@ func (e *CopilotEngine) computeCopilotToolArguments(tools map[string]any, safeOu
args = append(args, "--allow-tool", constants.SafeInputsMCPServerID)
}

// Handle web-fetch builtin tool (Copilot CLI uses web_fetch with underscore)
if _, hasWebFetch := tools["web-fetch"]; hasWebFetch {
// web-fetch -> web_fetch
args = append(args, "--allow-tool", "web_fetch")
}

// Built-in tool names that should be skipped when processing MCP servers
// Note: GitHub is NOT included here because it needs MCP configuration in CLI mode
// Note: web-fetch is NOT included here because it may be an MCP server for engines without native support
// Note: web-fetch is NOT included here because it needs explicit --allow-tool argument
builtInTools := map[string]bool{
"bash": true,
"edit": true,
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62 changes: 62 additions & 0 deletions pkg/workflow/fetch_integration_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,68 @@ Fetch content from the web.
}
}

// TestWebFetchNotAddedForCopilotEngine tests that when a Copilot workflow uses web-fetch,
// the web-fetch MCP server is NOT added (because Copilot has native support)
func TestWebFetchNotAddedForCopilotEngine(t *testing.T) {
// Create a temporary directory for the test
tmpDir := testutil.TempDir(t, "test-*")

// Create a test workflow that uses web-fetch with Copilot engine (which supports web-fetch natively)
workflowContent := `---
on: workflow_dispatch
permissions:
contents: read
issues: read
pull-requests: read
engine: copilot
tools:
web-fetch:
---

# Test Workflow

Fetch content from the web.
`

workflowPath := filepath.Join(tmpDir, "test-workflow.md")
if err := os.WriteFile(workflowPath, []byte(workflowContent), 0644); err != nil {
t.Fatalf("Failed to write test workflow: %v", err)
}

// Create a compiler
compiler := NewCompiler(false, "", "test")

// Compile the workflow
err := compiler.CompileWorkflow(workflowPath)
if err != nil {
t.Fatalf("Failed to compile workflow: %v", err)
}

// Read the generated lock file
lockPath := strings.TrimSuffix(workflowPath, ".md") + ".lock.yml"
lockData, err := os.ReadFile(lockPath)
if err != nil {
t.Fatalf("Failed to read lock file: %v", err)
}

// Verify that the compiled workflow does NOT contain the web-fetch MCP server configuration
lockContent := string(lockData)

// Check that web-fetch is NOT configured as an MCP server (no mcp_servers configuration)
if strings.Contains(lockContent, `[mcp_servers."web-fetch"]`) {
t.Errorf("Expected Copilot workflow NOT to contain web-fetch MCP server (since Copilot has native web-fetch support), but it did")
}

// Also check for JSON format MCP server config (though Copilot doesn't use JSON for MCP config)
if strings.Contains(lockContent, `"web-fetch": {`) && strings.Contains(lockContent, `"command": "docker"`) {
dockerIdx := strings.Index(lockContent, `"command": "docker"`)
webFetchIdx := strings.Index(lockContent, `"web-fetch": {`)
if dockerIdx > 0 && webFetchIdx > 0 && dockerIdx-webFetchIdx < 200 {
t.Errorf("Expected Copilot workflow NOT to contain web-fetch MCP server, but it did")
}
}
}

// TestNoWebFetchNoMCPFetchServer tests that when a workflow doesn't use web-fetch,
// the web-fetch MCP server is not added
func TestNoWebFetchNoMCPFetchServer(t *testing.T) {
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2 changes: 1 addition & 1 deletion pkg/workflow/fetch_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -214,7 +214,7 @@ func TestEngineSupportsWebFetch(t *testing.T) {
}{
{"claude", true},
{"codex", false},
{"copilot", false},
{"copilot", true}, // Copilot now supports web-fetch
{"custom", false},
}

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