From 8d3d4982457143e3476adcab7a7620ea331015ef Mon Sep 17 00:00:00 2001
From: vikingowl <christian@nachtigall.dev>
Date: Sun, 5 Apr 2026 23:06:23 +0200
Subject: [PATCH] =?UTF-8?q?feat:=20coordinator=20mode=20=E2=80=94=20system?=
 =?UTF-8?q?=20prompt=20injection=20for=20orchestration=20tasks?=
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---
 internal/engine/coordinator_test.go | 39 +++++++++++++++++++++++++++++
 internal/engine/loop.go             | 26 +++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 internal/engine/coordinator_test.go

diff --git a/internal/engine/coordinator_test.go b/internal/engine/coordinator_test.go
new file mode 100644
index 0000000..57deb4f
--- /dev/null
+++ b/internal/engine/coordinator_test.go
@@ -0,0 +1,39 @@
+package engine
+
+import (
+	"strings"
+	"testing"
+
+	"somegit.dev/Owlibou/gnoma/internal/router"
+)
+
+func TestCoordinatorSystemPrompt_InjectedForOrchestration(t *testing.T) {
+	prompt := coordinatorPrompt()
+	if !strings.Contains(prompt, "spawn_elfs") {
+		t.Error("coordinator prompt must mention spawn_elfs")
+	}
+	if !strings.Contains(prompt, "list_results") {
+		t.Error("coordinator prompt must mention list_results")
+	}
+}
+
+func TestShouldInjectCoordinatorPrompt(t *testing.T) {
+	cases := []struct {
+		prompt string
+		want   bool
+	}{
+		{"orchestrate the migration", true},
+		{"coordinate the refactor", true},
+		{"dispatch tasks to elfs", true},
+		{"fix the bug in main.go", false},
+		{"explain this function", false},
+		{"write unit tests for auth", false},
+	}
+	for _, c := range cases {
+		task := router.ClassifyTask(c.prompt)
+		got := task.Type == router.TaskOrchestration
+		if got != c.want {
+			t.Errorf("prompt %q: want orchestration=%v, got %v (type=%s)", c.prompt, c.want, got, task.Type)
+		}
+	}
+}
diff --git a/internal/engine/loop.go b/internal/engine/loop.go
index 13f5466..9d78a54 100644
--- a/internal/engine/loop.go
+++ b/internal/engine/loop.go
@@ -301,9 +301,35 @@ func (e *Engine) buildRequest(ctx context.Context) provider.Request {
 		)
 	}
 
+	// Inject coordinator guidance for orchestration tasks
+	if e.cfg.Router != nil {
+		prompt := ""
+		for i := len(e.history) - 1; i >= 0; i-- {
+			if e.history[i].Role == message.RoleUser {
+				prompt = e.history[i].TextContent()
+				break
+			}
+		}
+		if router.ClassifyTask(prompt).Type == router.TaskOrchestration {
+			req.SystemPrompt = coordinatorPrompt() + "\n\n" + req.SystemPrompt
+		}
+	}
+
 	return req
 }
 
+// coordinatorPrompt returns the system prompt block injected for orchestration tasks.
+func coordinatorPrompt() string {
+	return `You are operating in coordinator mode. Your role is to decompose complex work into parallel tasks and orchestrate elfs.
+
+Rules:
+- Use spawn_elfs to dispatch N tasks in parallel when they don't share write state.
+- Use list_results to discover outputs produced by prior tool calls in this session.
+- Pass result file paths to elfs in their prompts so they can read prior outputs with read_result or fs.read.
+- Writes are serial: if two elfs would write the same file, sequence them.
+- Synthesize elf outputs into a coherent final answer.`
+}
+
 func (e *Engine) executeTools(ctx context.Context, calls []message.ToolCall, cb Callback) ([]message.ToolResult, error) {
 	// Partition into read-only (parallel) and write (serial) batches
 	type toolCallWithTool struct {