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fix: use plugin-qualified MCP tool names in hooks #179

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Merged
aeneasr merged 1 commit into from
Aug 6, 2026
Merged

fix: use plugin-qualified MCP tool names in hooks #179

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37 changes: 25 additions & 12 deletions cmd/hook.go
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Original file line number Diff line number Diff line change
Expand Up @@ -48,14 +48,20 @@ func init() {
hookCmd.AddCommand(hookPreToolUseCmd)

hookSessionStartCmd.Flags().StringVar(&hookSessionStartHost, "host", hookHostClaude, "Hook host output format")
hookSessionStartCmd.Flags().StringVar(&hookSessionStartPluginName, "plugin-name", "", "Claude Code plugin name")
hookPreToolUseCmd.Flags().StringVar(&hookPreToolUsePluginName, "plugin-name", "", "Claude Code plugin name")
}

var hookCmd = &cobra.Command{
Use: "hook",
Short: "Hook handlers for AI coding agent integration",
}

var hookSessionStartHost string
var (
hookSessionStartHost string
hookSessionStartPluginName string
hookPreToolUsePluginName string
)

var hookSessionStartCmd = &cobra.Command{
Use: "session-start [mcp-name]",
Expand Down Expand Up @@ -104,24 +110,31 @@ func runHookSessionStart(_ *cobra.Command, args []string) error {
cwd, _ = os.Getwd()
}

content := generateSessionContextForHost(host, mcpName, cwd)
content := generateSessionContextForHost(host, mcpName, hookSessionStartPluginName, cwd)
out := sessionStartOutput(host, content)

enc := json.NewEncoder(os.Stdout)
enc.SetEscapeHTML(false)
return enc.Encode(out)
}

func generateSessionContextForHost(host, mcpName, cwd string) string {
return generateSessionContextInternalWithDirective(sessionStartDirective(host, mcpName), cwd, config.FindDonorIndex, spawnBackgroundIndexer)
func generateSessionContextForHost(host, mcpName, pluginName, cwd string) string {
return generateSessionContextInternalWithDirective(sessionStartDirective(host, mcpName, pluginName), cwd, config.FindDonorIndex, spawnBackgroundIndexer)
}

func sessionStartDirective(host, mcpName string) string {
func sessionStartDirective(host, mcpName, pluginName string) string {
if host == hookHostCursor {
return "Use the Lumen semantic_search tool first for any code discovery task — before Grep, Bash, or Read."
}
toolRef := "mcp__" + mcpName + "__semantic_search"
return "Call " + toolRef + " first for any code discovery task — before Grep, Bash, or Read."
toolRef := mcpToolReference(pluginName, mcpName, "semantic_search")
return "Load and call " + toolRef + " first for any code discovery task — before Grep, Bash, or Read."
}

func mcpToolReference(pluginName, mcpName, toolName string) string {
if pluginName != "" {
mcpName = "plugin_" + pluginName + "_" + mcpName
}
return "mcp__" + mcpName + "__" + toolName
}

func generateSessionContextInternalWithDirective(directive, cwd string, findDonor func(string, string) string, bgIndexer func(string)) string {
Expand Down Expand Up @@ -190,7 +203,7 @@ func generateSessionContextInternalWithDirective(directive, cwd string, findDono
// findDonor and bgIndexer are injected so tests can verify behaviour without
// spawning real processes or requiring a live git repository.
func generateSessionContextInternal(cwd string, findDonor func(string, string) string, bgIndexer func(string)) string {
return generateSessionContextInternalWithDirective(sessionStartDirective(hookHostClaude, "lumen"), cwd, findDonor, bgIndexer)
return generateSessionContextInternalWithDirective(sessionStartDirective(hookHostClaude, "lumen", ""), cwd, findDonor, bgIndexer)
}

func normalizeHookHost(host string) (string, error) {
Expand Down Expand Up @@ -243,7 +256,7 @@ func runHookPreToolUse(_ *cobra.Command, args []string) error {
return nil
}

result := evaluateToolCall(input, mcpName)
result := evaluateToolCall(input, mcpName, hookPreToolUsePluginName)
if result == nil {
// Silent allow — exit 0 with no stdout.
return nil
Expand All @@ -257,7 +270,7 @@ func runHookPreToolUse(_ *cobra.Command, args []string) error {
// evaluateToolCall determines whether a tool call should be intercepted
// with a suggestion to use semantic search instead.
// Returns nil for silent allow (no output), or a hookOutput with a suggestion.
func evaluateToolCall(input preToolUseInput, mcpName string) *hookOutput {
func evaluateToolCall(input preToolUseInput, mcpName, pluginName string) *hookOutput {
switch input.ToolName {
case "Grep", "Glob":
// Always suggest semantic search for any file/code search.
Expand All @@ -270,12 +283,12 @@ func evaluateToolCall(input preToolUseInput, mcpName string) *hookOutput {
return nil
}

toolRef := "mcp__" + mcpName + "__semantic_search"
toolRef := mcpToolReference(pluginName, mcpName, "semantic_search")
return &hookOutput{
HookSpecificOutput: hookSpecificOutput{
HookEventName: "PreToolUse",
AdditionalContext: fmt.Sprintf(
"Use %s instead of Grep/Glob/find/rg for significantly faster and better search results to reduce context window use and give better quality results.",
"Load and call %s instead of Grep/Glob/find/rg for significantly faster and better search results to reduce context window use and give better quality results.",
toolRef,
),
},
Expand Down
73 changes: 56 additions & 17 deletions cmd/hook_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,7 @@ func TestMain(m *testing.M) {
os.Exit(m.Run())
}

func TestGenerateSessionContext_NoIndex(t *testing.T) {
func TestGenerateSessionContext_NoIndexLegacyToolName(t *testing.T) {
// Use the internal version with a no-op bgIndexer to avoid spawning the
// test binary as a background process (which would trigger a fork bomb:
// the spawned binary runs all tests, which spawn more binaries, etc.)
Expand All @@ -71,16 +71,50 @@ func TestGenerateSessionContext_NoIndex(t *testing.T) {
func(_ string) {},
)
if !strings.Contains(content, "mcp__lumen__semantic_search") {
t.Error("content should reference the semantic_search tool")
t.Error("legacy content should reference the standalone semantic_search tool")
}
if strings.Contains(content, "EXTREMELY_IMPORTANT") {
t.Error("content should not contain EXTREMELY_IMPORTANT directives")
}
}

func TestMCPToolReference(t *testing.T) {
tests := []struct {
name string
pluginName string
want string
}{
{
name: "plugin qualified",
pluginName: "lumen",
want: "mcp__plugin_lumen_lumen__semantic_search",
},
{
name: "standalone",
want: "mcp__lumen__semantic_search",
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := mcpToolReference(tt.pluginName, "lumen", "semantic_search")
if got != tt.want {
t.Fatalf("mcpToolReference() = %q, want %q", got, tt.want)
}
})
}
}

func TestSessionStartDirectiveClaudePlugin(t *testing.T) {
const want = "Load and call mcp__plugin_lumen_lumen__semantic_search first for any code discovery task — before Grep, Bash, or Read."
if got := sessionStartDirective(hookHostClaude, "lumen", "lumen"); got != want {
t.Fatalf("sessionStartDirective() = %q, want %q", got, want)
}
}

func TestGenerateSessionContextForCursor_NoIndex(t *testing.T) {
content := generateSessionContextInternalWithDirective(
sessionStartDirective(hookHostCursor, "lumen"),
sessionStartDirective(hookHostCursor, "lumen", "lumen"),
"/nonexistent/path",
func(_, _ string) string { return "" },
func(_ string) {},
Expand All @@ -107,16 +141,16 @@ func TestEvaluateToolCall_GrepAlwaysSuggests(t *testing.T) {
ToolName: "Grep",
Input: map[string]any{"pattern": pattern},
}
result := evaluateToolCall(input, "lumen")
result := evaluateToolCall(input, "lumen", "lumen")
if result == nil {
t.Fatal("expected suggestion for Grep, got nil")
return
}
if result.HookSpecificOutput.PermissionDecision != "" {
t.Errorf("expected no permissionDecision, got %q", result.HookSpecificOutput.PermissionDecision)
}
if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__lumen__semantic_search") {
t.Error("additionalContext should reference semantic_search tool")
if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
}
})
}
Expand All @@ -127,22 +161,25 @@ func TestEvaluateToolCall_GlobAlwaysSuggests(t *testing.T) {
ToolName: "Glob",
Input: map[string]any{"pattern": "**/*.go"},
}
result := evaluateToolCall(input, "lumen")
result := evaluateToolCall(input, "lumen", "lumen")
if result == nil {
t.Fatal("expected suggestion for Glob, got nil")
return
}
if result.HookSpecificOutput.PermissionDecision != "" {
t.Errorf("expected no permissionDecision, got %q", result.HookSpecificOutput.PermissionDecision)
}
if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
}
}

func TestEvaluateToolCall_OtherToolSilentAllow(t *testing.T) {
input := preToolUseInput{
ToolName: "Read",
Input: map[string]any{"path": "/some/file.go"},
}
result := evaluateToolCall(input, "lumen")
result := evaluateToolCall(input, "lumen", "lumen")
if result != nil {
t.Errorf("expected nil (silent allow) for Read, got suggestion")
}
Expand All @@ -160,13 +197,13 @@ func TestEvaluateToolCall_BashGrepSuggests(t *testing.T) {
ToolName: "Bash",
Input: map[string]any{"command": cmd},
}
result := evaluateToolCall(input, "lumen")
result := evaluateToolCall(input, "lumen", "lumen")
if result == nil {
t.Fatal("expected suggestion for bash grep, got nil")
return
}
if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__lumen__semantic_search") {
t.Error("additionalContext should reference semantic_search tool")
if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
}
})
}
Expand All @@ -184,7 +221,7 @@ func TestEvaluateToolCall_BashNonSearchSilentAllow(t *testing.T) {
ToolName: "Bash",
Input: map[string]any{"command": cmd},
}
result := evaluateToolCall(input, "lumen")
result := evaluateToolCall(input, "lumen", "lumen")
if result != nil {
t.Errorf("expected nil for non-search bash command %q, got suggestion", cmd)
}
Expand All @@ -196,7 +233,7 @@ func TestPreToolUseOutputJSON(t *testing.T) {
result := evaluateToolCall(preToolUseInput{
ToolName: "Grep",
Input: map[string]any{"pattern": "error handling middleware"},
}, "lumen")
}, "lumen", "lumen")
if result == nil {
t.Fatal("expected non-nil result")
}
Expand Down Expand Up @@ -432,7 +469,9 @@ func TestGenerateSessionContextInternal_NonGitUsesParentIndex(t *testing.T) {
func TestHookOutputJSON(t *testing.T) {
// Use the internal version with a no-op bgIndexer — same fork-bomb reason
// as in TestGenerateSessionContext_NoIndex.
content := generateSessionContextInternal("/nonexistent/path",
content := generateSessionContextInternalWithDirective(
sessionStartDirective(hookHostClaude, "lumen", "lumen"),
"/nonexistent/path",
func(_, _ string) string { return "" },
func(_ string) {},
)
Expand Down Expand Up @@ -461,14 +500,14 @@ func TestHookOutputJSON(t *testing.T) {
t.Errorf("hookEventName = %v, want SessionStart", hso["hookEventName"])
}
ctx, ok := hso["additionalContext"].(string)
if !ok || !strings.Contains(ctx, "mcp__lumen__semantic_search") {
t.Error("additionalContext should contain tool reference")
if !ok || !strings.Contains(ctx, "mcp__plugin_lumen_lumen__semantic_search") {
t.Error("additionalContext should contain the plugin-qualified tool reference")
}
}

func TestSessionStartOutputCursorJSON(t *testing.T) {
content := generateSessionContextInternalWithDirective(
sessionStartDirective(hookHostCursor, "lumen"),
sessionStartDirective(hookHostCursor, "lumen", "lumen"),
"/nonexistent/path",
func(_, _ string) string { return "" },
func(_ string) {},
Expand Down
4 changes: 2 additions & 2 deletions hooks/hooks.json
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
"hooks": [
{
"type": "command",
"command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook session-start lumen --host claude"
"command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook session-start lumen --host claude --plugin-name lumen"
}
]
}
Expand All @@ -17,7 +17,7 @@
"hooks": [
{
"type": "command",
"command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook pre-tool-use lumen"
"command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook pre-tool-use lumen --plugin-name lumen"
}
]
}
Expand Down
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