feat(agentic): expose prompt snapshot over MCP

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/agentic/prep.go

@@ -92,6 +92,7 @@ func (s *PrepSubsystem) OnStartup(ctx context.Context) core.Result {
 		case "agentic.status", "agentic.scan", "agentic.watch",
 			"agentic.issue.get", "agentic.issue.list", "agentic.issue.assign", "agentic.pr.get", "agentic.pr.list",
 			"agentic.prompt", "agentic.task", "agentic.flow", "agentic.persona",
+			"agentic.prompt.version",
 			"agentic.sync.status", "agentic.fleet.nodes", "agentic.fleet.stats", "agentic.fleet.events",
 			"agentic.credits.balance", "agentic.credits.history",
 			"agentic.subscription.detect", "agentic.subscription.budget",
@@ -385,6 +386,7 @@ func (s *PrepSubsystem) RegisterTools(server *mcp.Server) {
 	s.registerStateTools(server)
 	s.registerPhaseTools(server)
 	s.registerTaskTools(server)
+	s.registerPromptTools(server)
 	s.registerTemplateTools(server)
 	s.registerIssueTools(server)
 	s.registerMessageTools(server)

pkg/agentic/prep_test.go

@@ -654,6 +654,7 @@ func TestPrep_RegisterTools_Good_RegistersCompletionTool(t *testing.T) {
 	}
 
 	assert.Contains(t, toolNames, "agentic_complete")
+	assert.Contains(t, toolNames, "agentic_prompt_version")
 	assert.Contains(t, toolNames, "session_complete")
 	assert.Contains(t, toolNames, "agentic_message_send")
 	assert.Contains(t, toolNames, "agentic_message_inbox")

pkg/agentic/prompt_version.go

@@ -16,6 +16,11 @@ type PromptVersionOutput struct {
 	Snapshot  PromptVersionSnapshot `json:"snapshot"`
 }
 
+// input := agentic.PromptVersionInput{Workspace: "/srv/.core/workspace/core/go-io/task-42"}
+type PromptVersionInput struct {
+	Workspace string `json:"workspace"`
+}
+
 // result := c.Action("agentic.prompt.version").Run(ctx, core.NewOptions(
 //
 //	core.Option{Key: "workspace", Value: "/srv/.core/workspace/core/go-io/task-42"},
@@ -47,3 +52,18 @@ func (s *PrepSubsystem) promptVersion(_ context.Context, _ *mcp.CallToolRequest,
 		Snapshot:  snapshot,
 	}, nil
 }
+
+func (s *PrepSubsystem) registerPromptTools(server *mcp.Server) {
+	mcp.AddTool(server, &mcp.Tool{
+		Name:        "agentic_prompt_version",
+		Description: "Read the current prompt snapshot for a workspace.",
+	}, s.promptVersionTool)
+}
+
+func (s *PrepSubsystem) promptVersionTool(ctx context.Context, _ *mcp.CallToolRequest, input PromptVersionInput) (*mcp.CallToolResult, PromptVersionOutput, error) {
+	if core.Trim(input.Workspace) == "" {
+		return nil, PromptVersionOutput{}, core.E("promptVersion", "workspace is required", nil)
+	}
+
+	return s.promptVersion(ctx, nil, input.Workspace)
+}

pkg/agentic/prompt_version_test.go

@@ -3,6 +3,7 @@
 package agentic
 
 import (
+	"context"
 	"testing"
 
 	core "dappco.re/go/core"
@@ -41,3 +42,38 @@ func TestPromptVersion_ReadPromptSnapshot_Ugly_InvalidJson(t *testing.T) {
 	require.Error(t, err)
 	assert.Contains(t, err.Error(), "failed to parse prompt snapshot")
 }
+
+func TestPromptVersion_PromptVersionTool_Good(t *testing.T) {
+	workspaceDir := t.TempDir()
+	prompt := "TASK: Fix tests\n\nRead CODEX.md and commit when done."
+
+	require.True(t, writePromptSnapshot(workspaceDir, prompt).OK)
+
+	_, output, err := (&PrepSubsystem{}).promptVersionTool(context.Background(), nil, PromptVersionInput{
+		Workspace: workspaceDir,
+	})
+	require.NoError(t, err)
+
+	assert.True(t, output.Success)
+	assert.Equal(t, workspaceDir, output.Workspace)
+	assert.Equal(t, promptSnapshotHash(prompt), output.Snapshot.Hash)
+}
+
+func TestPromptVersion_PromptVersionTool_Bad_MissingWorkspace(t *testing.T) {
+	_, _, err := (&PrepSubsystem{}).promptVersionTool(context.Background(), nil, PromptVersionInput{})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "workspace is required")
+}
+
+func TestPromptVersion_PromptVersionTool_Ugly_InvalidJson(t *testing.T) {
+	workspaceDir := t.TempDir()
+	metaDir := WorkspaceMetaDir(workspaceDir)
+	require.True(t, fs.EnsureDir(metaDir).OK)
+	require.True(t, fs.Write(core.JoinPath(metaDir, "prompt-version.json"), "{not-json").OK)
+
+	_, _, err := (&PrepSubsystem{}).promptVersionTool(context.Background(), nil, PromptVersionInput{
+		Workspace: workspaceDir,
+	})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "failed to parse prompt snapshot")
+}