Add Antigravity (agy) as a third agent backend for gemini-* models

internal/agents/process.go

@@ -5,8 +5,11 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"path/filepath"
+	"strings"
 	"time"
 
+	"g.fc.run/ai/byre/internal/antigravity"
 	"g.fc.run/ai/byre/internal/api"
 	"g.fc.run/ai/byre/internal/claude"
 	"g.fc.run/ai/byre/internal/codex"
@@ -32,7 +35,7 @@ type agentProcess interface {
 }
 
 func initialVendorSessionID(vendor api.AgentSessionVendor, id string) string {
-	if vendor == api.Codex {
+	if vendor != api.Claude {
 		return ""
 	}
 	return id
@@ -238,3 +241,86 @@ func (p codexProcess) drive(m *Manager, l *live) {
 		}
 	}
 }
+
+type antigravityProcess struct {
+	s     *antigravity.Session
+	steps *agySteps
+}
+
+func (m *Manager) startAntigravity(ctx context.Context, sess api.AgentSession, l *live, g string, servers []*mcp.Server, stdio []mcp.Stdio, env []string) (agentProcess, error) {
+	opts := antigravity.Options{
+		Dir:        filepath.Join(m.antigravityRoot, sess.Id),
+		Cwd:        l.dir,
+		Model:      sess.Model,
+		Resume:     sess.VendorSessionId,
+		GitName:    l.gitName,
+		GitEmail:   l.gitEmail,
+		Env:        env,
+		Guidance:   g,
+		Notes:      strings.TrimSpace(l.notes),
+		Reminder:   g,
+		MCPServers: servers,
+		StdioMCP:   stdio,
+		Hooks:      map[string]antigravity.HookFunc{"PreInvocation": m.agyBeforeModel(l)},
+		OnBadLine:  func(line []byte, reason string) { m.recordBadLine(l, line, reason) },
+	}
+
+	s, err := antigravity.Start(ctx, opts)
+	if err != nil {
+		return nil, fmt.Errorf("start agy: %w", err)
+	}
+	if sess.VendorSessionId == "" {
+		err = m.store.SetVendorSessionID(ctx, sess.Id, s.ID())
+		if err != nil {
+			s.Kill()
+			return nil, err
+		}
+	}
+	return antigravityProcess{s: s, steps: newAgySteps()}, nil
+}
+
+func (p antigravityProcess) send(ctx context.Context, text string, images []image) error {
+	imgs := []antigravity.Image{}
+	for _, img := range images {
+		imgs = append(imgs, antigravity.Image{MediaType: img.mediaType, Data: img.data})
+	}
+	return p.s.Send(text, imgs...)
+}
+
+func (p antigravityProcess) interrupt(ctx context.Context) error {
+	return p.s.Interrupt()
+}
+
+func (p antigravityProcess) setModel(ctx context.Context, model string) error {
+	return p.s.SetModel(model)
+}
+
+func (p antigravityProcess) kill()               { p.s.Kill() }
+func (p antigravityProcess) pid() int            { return p.s.Pid() }
+func (p antigravityProcess) lastLine() time.Time { return p.s.LastLine() }
+func (p antigravityProcess) exited() bool        { return p.s.Exited() }
+
+func (p antigravityProcess) discard() {
+	for range p.s.Events() {
+	}
+}
+
+func (p antigravityProcess) drive(m *Manager, l *live) {
+	ctx := context.Background()
+	for ev := range p.s.Events() {
+		start := time.Now()
+		if wait := start.Sub(ev.Read); wait > 200*time.Millisecond {
+			slog.Info("agent event waited", "session", l.id, "event", ev.Kind, "wait", wait)
+		}
+		err := m.handleAntigravity(ctx, l, p, ev)
+		if err != nil {
+			slog.Error("record agent event", "session", l.id, "event", ev.Kind, "err", err)
+		}
+		if isDecodeError(err) {
+			m.recordBadLine(l, ev.Raw, fmt.Sprintf("decode %s: %s", ev.Kind, err))
+		}
+		if took := time.Since(start); took > 200*time.Millisecond {
+			slog.Info("agent event slow", "session", l.id, "event", ev.Kind, "took", took)
+		}
+	}
+}