Merge agentcore into agent; decouple pkg/core from internal/agent

AgentCore (the Core interface impl) belongs in internal/agent alongside
the loop, session, and state it orchestrates — not in a separate one-file
package.

To break the resulting import cycle (agent → pkg/core → agent), define
Event and EventHandler natively in pkg/core instead of aliasing from
internal/agent. The agent loop now imports pkg/core for these types.
Usage token tracking is internal to the loop and no longer emitted as
an event (no consumer used it).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/ollie/main.go

@@ -8,7 +8,7 @@ import (
 	"os"
 
 	"ollie/internal/agent"
-	"ollie/internal/agentcore"
+	
 	"ollie/internal/backend"
 	"ollie/internal/config"
 	execpkg "ollie/internal/exec"
@@ -36,10 +36,10 @@ func main() {
 		os.Exit(1)
 	}
 
-	backendName := agentcore.ResolveBackendName()
+	backendName := agent.ResolveBackendName()
 	modelName := os.Getenv("OLLIE_MODEL")
 	if modelName == "" {
-		modelName = agentcore.DefaultModelForBackend(backendName)
+		modelName = agent.DefaultModelForBackend(backendName)
 	}
 
 	builtinExec := execpkg.New(
@@ -52,7 +52,7 @@ func main() {
 		agentName = "default"
 	}
 
-	sessionID := agentcore.NewSessionID()
+	sessionID := agent.NewSessionID()
 	var resumeMessages []backend.Message
 	if *sessionFlag != "" {
 		sessionPath := sessionsDir + "/" + *sessionFlag + ".json"
@@ -76,9 +76,9 @@ func main() {
 		agentName = extraArgs[0]
 	}
 
-	cfgPath := agentcore.AgentConfigPath(agentsDir, agentName)
+	cfgPath := agent.AgentConfigPath(agentsDir, agentName)
 	cfg, cfgErr := config.Load(cfgPath)
-	env := agentcore.BuildAgentEnv(cfg, builtinExec)
+	env := agent.BuildAgentEnv(cfg, builtinExec)
 
 	var initialSession *agent.Session
 	if len(resumeMessages) > 0 {
@@ -87,7 +87,7 @@ func main() {
 		})
 	}
 
-	agentCore := agentcore.NewAgentCore(agentcore.AgentCoreConfig{
+	agentCore := agent.NewAgentCore(agent.AgentCoreConfig{
 		Backend:     be,
 		BackendName: backendName,
 		ModelName:   modelName,

internal/agent/core.go

@@ -1,4 +1,4 @@
-package agentcore
+package agent
 
 import (
 	"bytes"
@@ -16,7 +16,6 @@ import (
 
 	"crypto/rand"
 
-	"ollie/internal/agent"
 	"ollie/internal/backend"
 	"ollie/internal/config"
 	execpkg "ollie/internal/exec"
@@ -218,8 +217,8 @@ var BuiltinTools = []backend.Tool{
 type AgentEnv struct {
 	McpExec          *tools.Executor
 	Tools            []backend.Tool
-	Exec             agent.ToolExecutor
-	Confirm          *agent.ConfirmFn
+	Exec             ToolExecutor
+	Confirm          *ConfirmFn
 	Hooks            core.Hooks
 	SystemPrompt     string
 	GenParams        backend.GenerationParams
@@ -298,7 +297,7 @@ func BuildAgentEnv(cfg *config.Config, builtinExec *execpkg.Executor) AgentEnv {
 		builtinNames[t.Name] = struct{}{}
 	}
 
-	var confirmFn agent.ConfirmFn
+	var confirmFn ConfirmFn
 	confirmPtr := &confirmFn
 
 	fileReadCache := make(map[string]bool)
@@ -313,7 +312,7 @@ func BuildAgentEnv(cfg *config.Config, builtinExec *execpkg.Executor) AgentEnv {
 			return extractMCPText(raw), nil
 		}
 		if _, ok := builtinNames[name]; ok {
-			var cfn agent.ConfirmFn
+			var cfn ConfirmFn
 			if _, trusted := trustedTools[name]; !trusted {
 				cfn = *confirmPtr
 			}
@@ -484,7 +483,7 @@ type AgentCoreConfig struct {
 	AgentsDir   string
 	SessionsDir string
 	SessionID   string
-	Session     *agent.Session
+	Session     *Session
 	Env         AgentEnv
 	BuiltinExec *execpkg.Executor
 }
@@ -492,8 +491,8 @@ type AgentCoreConfig struct {
 // AgentCore is the Core implementation. It owns all agent and session state
 // but has no knowledge of how output is rendered.
 type AgentCore struct {
-	session          *agent.Session
-	loopcfg          agent.Config
+	session          *Session
+	loopcfg          Config
 	hooks            core.Hooks
 	modelName        string
 	backendName      string
@@ -503,7 +502,7 @@ type AgentCore struct {
 	sessionID        string
 	mcpExec          *tools.Executor
 	builtinExec      *execpkg.Executor
-	confirmPtr       *agent.ConfirmFn
+	confirmPtr       *ConfirmFn
 	ctxOverhead      int
 	invalidateCaches func()
 	currentAction    atomic.Pointer[actionHandle]
@@ -513,7 +512,7 @@ var _ core.Core = (*AgentCore)(nil) // compile-time interface check
 
 // NewAgentCore creates an AgentCore from the given configuration.
 func NewAgentCore(cfg AgentCoreConfig) *AgentCore {
-	loopcfg := agent.Config{
+	loopcfg := Config{
 		Backend:          cfg.Backend,
 		Model:            cfg.ModelName,
 		SystemPrompt:     cfg.Env.SystemPrompt,
@@ -585,7 +584,7 @@ func (s *AgentCore) Submit(ctx context.Context, input string, handler core.Event
 	s.hooks.Run(core.HookUserPromptSubmit)
 
 	if s.session == nil {
-		s.session = agent.NewSessionWithConfig(BuildFirstPrompt(input), agent.ContextConfig{
+		s.session = NewSessionWithConfig(BuildFirstPrompt(input), ContextConfig{
 			FixedOverheadChars: s.ctxOverhead,
 		})
 	} else {
@@ -601,7 +600,7 @@ func (s *AgentCore) Submit(ctx context.Context, input string, handler core.Event
 
 	s.hooks.Run(core.HookAgentSpawn)
 
-	err := agent.Run(actCtx, s.loopcfg, s.session)
+	err := Run(actCtx, s.loopcfg, s.session)
 	actCancel(nil)
 	s.currentAction.CompareAndSwap(handle, nil)
 
@@ -805,7 +804,7 @@ func (s *AgentCore) handleCommand(ctx context.Context, input string, handler cor
 			}
 			label := id
 			if data, readErr := os.ReadFile(s.sessionsDir + "/" + e.Name()); readErr == nil {
-				var ps agent.PersistedSession
+				var ps PersistedSession
 				if json.Unmarshal(data, &ps) == nil {
 					goal := ""
 					for _, msg := range ps.Messages {
@@ -884,7 +883,7 @@ func extractMCPText(raw json.RawMessage) string {
 	return strings.Join(parts, "\n")
 }
 
-func dispatchBuiltinExec(ctx context.Context, name string, e *execpkg.Executor, confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchBuiltinExec(ctx context.Context, name string, e *execpkg.Executor, confirm ConfirmFn, args json.RawMessage) (string, error) {
 	switch name {
 	case "file_read":
 		return dispatchFileRead(confirm, args)
@@ -925,7 +924,7 @@ func execArgs(args json.RawMessage) (code, language, sandbox string, timeout int
 	return
 }
 
-func dispatchExecuteCode(ctx context.Context, e *execpkg.Executor, confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchExecuteCode(ctx context.Context, e *execpkg.Executor, confirm ConfirmFn, args json.RawMessage) (string, error) {
 	code, language, sandbox, timeout, err := execArgs(args)
 	if err != nil {
 		return "", fmt.Errorf("execute_code: bad args: %w", err)
@@ -939,7 +938,7 @@ func dispatchExecuteCode(ctx context.Context, e *execpkg.Executor, confirm agent
 	return e.Execute(ctx, code, language, timeout, sandbox, false)
 }
 
-func dispatchExecuteTool(ctx context.Context, e *execpkg.Executor, confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchExecuteTool(ctx context.Context, e *execpkg.Executor, confirm ConfirmFn, args json.RawMessage) (string, error) {
 	var a struct {
 		Tool     string   `json:"tool"`
 		Args     []string `json:"args"`
@@ -983,7 +982,7 @@ func dispatchExecuteTool(ctx context.Context, e *execpkg.Executor, confirm agent
 	return e.Execute(ctx, code, language, timeout, sandbox, true)
 }
 
-func dispatchExecutePipe(ctx context.Context, e *execpkg.Executor, confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchExecutePipe(ctx context.Context, e *execpkg.Executor, confirm ConfirmFn, args json.RawMessage) (string, error) {
 	var a struct {
 		Pipe    []execpkg.PipeStep `json:"pipe"`
 		Timeout int                `json:"timeout"`
@@ -1013,7 +1012,7 @@ func dispatchExecutePipe(ctx context.Context, e *execpkg.Executor, confirm agent
 	return e.Execute(ctx, code, "bash", timeout, sandbox, true)
 }
 
-func dispatchFileRead(confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchFileRead(confirm ConfirmFn, args json.RawMessage) (string, error) {
 	var a struct {
 		Path string `json:"path"`
 	}
@@ -1038,7 +1037,7 @@ func dispatchFileRead(confirm agent.ConfirmFn, args json.RawMessage) (string, er
 	return strings.TrimRight(out.String(), "\n"), nil
 }
 
-func dispatchFileWrite(confirm agent.ConfirmFn, args json.RawMessage) (string, error) {
+func dispatchFileWrite(confirm ConfirmFn, args json.RawMessage) (string, error) {
 	var a struct {
 		Path      string `json:"path"`
 		Content   string `json:"content"`

internal/agent/loop.go

@@ -9,19 +9,12 @@ import (
 	"time"
 
 	"ollie/internal/backend"
+	"ollie/pkg/core"
 )
 
 const maxRateLimitRetries = 3
 
 type ToolExecutor func(ctx context.Context, name string, args json.RawMessage) (string, error)
-type OutputFn func(msg OutputMsg)
-
-type OutputMsg struct {
-	Role    string
-	Name    string
-	Content string
-	Usage   backend.Usage
-}
 
 type Config struct {
 	Backend          backend.Backend
@@ -30,7 +23,7 @@ type Config struct {
 	Exec             ToolExecutor
 	Confirm          ConfirmFn
 	MaxSteps         int
-	Output           OutputFn
+	Output           core.EventHandler
 	SystemPrompt     string
 	GenerationParams backend.GenerationParams
 }
@@ -77,18 +70,16 @@ func Run(ctx context.Context, cfg Config, state State) error {
 
 		var content strings.Builder
 		var toolCalls []backend.ToolCall
-		var usage backend.Usage
 		var stopReason string
 		var done bool
 
 		for ev := range ch {
 			if ev.Content != "" {
 				content.WriteString(ev.Content)
-				emit(cfg, OutputMsg{Role: "assistant", Content: ev.Content})
+				emit(cfg, core.Event{Role: "assistant", Content: ev.Content})
 			}
 			toolCalls = append(toolCalls, ev.ToolCalls...)
 			if ev.Done {
-				usage = ev.Usage
 				stopReason = ev.StopReason
 				done = true
 				break
@@ -120,7 +111,7 @@ func Run(ctx context.Context, cfg Config, state State) error {
 				})
 				continue
 			}
-			emit(cfg, OutputMsg{Role: "call", Name: tc.Name, Content: string(tc.Arguments)})
+			emit(cfg, core.Event{Role: "call", Name: tc.Name, Content: string(tc.Arguments)})
 
 			var result string
 			var isErr bool
@@ -143,13 +134,10 @@ func Run(ctx context.Context, cfg Config, state State) error {
 				Content:    result,
 				IsError:    isErr,
 			})
-			emit(cfg, OutputMsg{Role: "tool", Name: tc.Name, Content: result})
+			emit(cfg, core.Event{Role: "tool", Name: tc.Name, Content: result})
 		}
 
-		// Emit usage when we have real token counts.
-		if usage.InputTokens > 0 || usage.OutputTokens > 0 {
-			emit(cfg, OutputMsg{Role: "usage", Usage: usage})
-		}
+
 
 		if err := state.Update(msg, results); err != nil {
 			return fmt.Errorf("step %d update: %w", step, err)
@@ -169,13 +157,13 @@ func Run(ctx context.Context, cfg Config, state State) error {
 
 	// Surface stall: only when the step limit was hit without completing.
 	if hitLimit {
-		emit(cfg, OutputMsg{Role: "stalled", Content: "max steps"})
+		emit(cfg, core.Event{Role: "stalled", Content: "max steps"})
 	}
 
 	return nil
 }
 
-func emit(cfg Config, msg OutputMsg) {
+func emit(cfg Config, msg core.Event) {
 	if cfg.Output != nil {
 		cfg.Output(msg)
 	}
@@ -192,7 +180,7 @@ func retryCountdown(ctx context.Context, cfg Config, wait time.Duration) error {
 			return nil
 		}
 		secs := int(remaining.Seconds()) + 1
-		emit(cfg, OutputMsg{Role: "retry", Content: fmt.Sprintf("%d", secs)})
+		emit(cfg, core.Event{Role: "retry", Content: fmt.Sprintf("%d", secs)})
 		select {
 		case <-ctx.Done():
 			return ctx.Err()

pkg/core/core.go

@@ -3,8 +3,6 @@ package core
 import (
 	"context"
 	"errors"
-
-	"ollie/internal/agent"
 )
 
 // ErrInterrupted is returned when the user cancels an agent turn (Ctrl-C).
@@ -12,10 +10,14 @@ var ErrInterrupted = errors.New("interrupted")
 
 // Event is a typed output event emitted by the Core during an agent turn
 // or in response to a command.
-type Event = agent.OutputMsg
+type Event struct {
+	Role    string
+	Name    string
+	Content string
+}
 
 // EventHandler receives events from the Core.
-type EventHandler = agent.OutputFn
+type EventHandler func(Event)
 
 // Core is the interface between a frontend (TUI, HTTP handler, etc.) and the
 // agent engine. All output from the agent is delivered via EventHandler.