Context Window Warning (#152)

* context window warning & compact command

* auto compact

* fix permissions

* update readme

* fix 3.5 context window

* small update

* remove unused interface

* remove unused msg

Author: kujtimiihoxha

README.md

@@ -62,12 +62,29 @@ OpenCode looks for configuration in the following locations:
 - `$XDG_CONFIG_HOME/opencode/.opencode.json`
 - `./.opencode.json` (local directory)
 
+### Auto Compact Feature
+
+OpenCode includes an auto compact feature that automatically summarizes your conversation when it approaches the model's context window limit. When enabled (default setting), this feature:
+
+- Monitors token usage during your conversation
+- Automatically triggers summarization when usage reaches 95% of the model's context window
+- Creates a new session with the summary, allowing you to continue your work without losing context
+- Helps prevent "out of context" errors that can occur with long conversations
+
+You can enable or disable this feature in your configuration file:
+
+```json
+{
+  "autoCompact": true // default is true
+}
+```
+
 ### Environment Variables
 
 You can configure OpenCode using environment variables:
 
 | Environment Variable       | Purpose                                                |
-|----------------------------|--------------------------------------------------------|
+| -------------------------- | ------------------------------------------------------ |
 | `ANTHROPIC_API_KEY`        | For Claude models                                      |
 | `OPENAI_API_KEY`           | For OpenAI models                                      |
 | `GEMINI_API_KEY`           | For Google Gemini models                               |
@@ -79,7 +96,6 @@ You can configure OpenCode using environment variables:
 | `AZURE_OPENAI_API_KEY`     | For Azure OpenAI models (optional when using Entra ID) |
 | `AZURE_OPENAI_API_VERSION` | For Azure OpenAI models                                |
 
-
 ### Configuration File Structure
 
 ```json
@@ -134,7 +150,8 @@ You can configure OpenCode using environment variables:
     }
   },
   "debug": false,
-  "debugLSP": false
+  "debugLSP": false,
+  "autoCompact": true
 }
 ```
 
@@ -327,9 +344,11 @@ OpenCode supports custom commands that can be created by users to quickly send p
 Custom commands are predefined prompts stored as Markdown files in one of three locations:
 
 1. **User Commands** (prefixed with `user:`):
+
    ```
    $XDG_CONFIG_HOME/opencode/commands/
    ```
+
    (typically `~/.config/opencode/commands/` on Linux/macOS)
 
    or
@@ -382,6 +401,15 @@ This creates a command with ID `user:git:commit`.
 
 The content of the command file will be sent as a message to the AI assistant.
 
+### Built-in Commands
+
+OpenCode includes several built-in commands:
+
+| Command            | Description                                                                                         |
+| ------------------ | --------------------------------------------------------------------------------------------------- |
+| Initialize Project | Creates or updates the OpenCode.md memory file with project-specific information                    |
+| Compact Session    | Manually triggers the summarization of the current session, creating a new session with the summary |
+
 ## MCP (Model Context Protocol)
 
 OpenCode implements the Model Context Protocol (MCP) to extend its capabilities through external tools. MCP provides a standardized way for the AI assistant to interact with external services and tools.

cmd/root.go

@@ -218,6 +218,7 @@ func setupSubscriptions(app *app.App, parentCtx context.Context) (chan tea.Msg,
 	setupSubscriber(ctx, &wg, "sessions", app.Sessions.Subscribe, ch)
 	setupSubscriber(ctx, &wg, "messages", app.Messages.Subscribe, ch)
 	setupSubscriber(ctx, &wg, "permissions", app.Permissions.Subscribe, ch)
+	setupSubscriber(ctx, &wg, "coderAgent", app.CoderAgent.Subscribe, ch)
 
 	cleanupFunc := func() {
 		logging.Info("Cancelling all subscriptions")

internal/config/config.go

@@ -36,9 +36,10 @@ type MCPServer struct {
 type AgentName string
 
 const (
-	AgentCoder AgentName = "coder"
-	AgentTask  AgentName = "task"
-	AgentTitle AgentName = "title"
+	AgentCoder      AgentName = "coder"
+	AgentSummarizer AgentName = "summarizer"
+	AgentTask       AgentName = "task"
+	AgentTitle      AgentName = "title"
 )
 
 // Agent defines configuration for different LLM models and their token limits.
@@ -84,6 +85,7 @@ type Config struct {
 	DebugLSP     bool                              `json:"debugLSP,omitempty"`
 	ContextPaths []string                          `json:"contextPaths,omitempty"`
 	TUI          TUIConfig                         `json:"tui"`
+	AutoCompact  bool                              `json:"autoCompact,omitempty"`
 }
 
 // Application constants
@@ -213,6 +215,7 @@ func setDefaults(debug bool) {
 	viper.SetDefault("data.directory", defaultDataDirectory)
 	viper.SetDefault("contextPaths", defaultContextPaths)
 	viper.SetDefault("tui.theme", "opencode")
+	viper.SetDefault("autoCompact", true)
 
 	if debug {
 		viper.SetDefault("debug", true)
@@ -262,6 +265,7 @@ func setProviderDefaults() {
 	// Anthropic configuration
 	if key := viper.GetString("providers.anthropic.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.Claude37Sonnet)
+		viper.SetDefault("agents.summarizer.model", models.Claude37Sonnet)
 		viper.SetDefault("agents.task.model", models.Claude37Sonnet)
 		viper.SetDefault("agents.title.model", models.Claude37Sonnet)
 		return
@@ -270,6 +274,7 @@ func setProviderDefaults() {
 	// OpenAI configuration
 	if key := viper.GetString("providers.openai.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.GPT41)
+		viper.SetDefault("agents.summarizer.model", models.GPT41)
 		viper.SetDefault("agents.task.model", models.GPT41Mini)
 		viper.SetDefault("agents.title.model", models.GPT41Mini)
 		return
@@ -278,6 +283,7 @@ func setProviderDefaults() {
 	// Google Gemini configuration
 	if key := viper.GetString("providers.gemini.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.Gemini25)
+		viper.SetDefault("agents.summarizer.model", models.Gemini25)
 		viper.SetDefault("agents.task.model", models.Gemini25Flash)
 		viper.SetDefault("agents.title.model", models.Gemini25Flash)
 		return
@@ -286,6 +292,7 @@ func setProviderDefaults() {
 	// Groq configuration
 	if key := viper.GetString("providers.groq.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.QWENQwq)
+		viper.SetDefault("agents.summarizer.model", models.QWENQwq)
 		viper.SetDefault("agents.task.model", models.QWENQwq)
 		viper.SetDefault("agents.title.model", models.QWENQwq)
 		return
@@ -294,6 +301,7 @@ func setProviderDefaults() {
 	// OpenRouter configuration
 	if key := viper.GetString("providers.openrouter.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.OpenRouterClaude37Sonnet)
+		viper.SetDefault("agents.summarizer.model", models.OpenRouterClaude37Sonnet)
 		viper.SetDefault("agents.task.model", models.OpenRouterClaude37Sonnet)
 		viper.SetDefault("agents.title.model", models.OpenRouterClaude35Haiku)
 		return
@@ -302,6 +310,7 @@ func setProviderDefaults() {
 	// XAI configuration
 	if key := viper.GetString("providers.xai.apiKey"); strings.TrimSpace(key) != "" {
 		viper.SetDefault("agents.coder.model", models.XAIGrok3Beta)
+		viper.SetDefault("agents.summarizer.model", models.XAIGrok3Beta)
 		viper.SetDefault("agents.task.model", models.XAIGrok3Beta)
 		viper.SetDefault("agents.title.model", models.XAiGrok3MiniFastBeta)
 		return
@@ -310,6 +319,7 @@ func setProviderDefaults() {
 	// AWS Bedrock configuration
 	if hasAWSCredentials() {
 		viper.SetDefault("agents.coder.model", models.BedrockClaude37Sonnet)
+		viper.SetDefault("agents.summarizer.model", models.BedrockClaude37Sonnet)
 		viper.SetDefault("agents.task.model", models.BedrockClaude37Sonnet)
 		viper.SetDefault("agents.title.model", models.BedrockClaude37Sonnet)
 		return
@@ -318,6 +328,7 @@ func setProviderDefaults() {
 	// Azure OpenAI configuration
 	if os.Getenv("AZURE_OPENAI_ENDPOINT") != "" {
 		viper.SetDefault("agents.coder.model", models.AzureGPT41)
+		viper.SetDefault("agents.summarizer.model", models.AzureGPT41)
 		viper.SetDefault("agents.task.model", models.AzureGPT41Mini)
 		viper.SetDefault("agents.title.model", models.AzureGPT41Mini)
 		return

internal/llm/agent/agent-tool.go

@@ -69,11 +69,11 @@ func (b *agentTool) Run(ctx context.Context, call tools.ToolCall) (tools.ToolRes
 		return tools.ToolResponse{}, fmt.Errorf("error generating agent: %s", err)
 	}
 	result := <-done
-	if result.Err() != nil {
-		return tools.ToolResponse{}, fmt.Errorf("error generating agent: %s", result.Err())
+	if result.Error != nil {
+		return tools.ToolResponse{}, fmt.Errorf("error generating agent: %s", result.Error)
 	}
 
-	response := result.Response()
+	response := result.Message
 	if response.Role != message.Assistant {
 		return tools.NewTextErrorResponse("no response"), nil
 	}
@@ -88,8 +88,6 @@ func (b *agentTool) Run(ctx context.Context, call tools.ToolCall) (tools.ToolRes
 	}
 
 	parentSession.Cost += updatedSession.Cost
-	parentSession.PromptTokens += updatedSession.PromptTokens
-	parentSession.CompletionTokens += updatedSession.CompletionTokens
 
 	_, err = b.sessions.Save(ctx, parentSession)
 	if err != nil {