--- title: Configuration description: Configuration overrides, dynamic runtime configuration, Session integration, and package exports for the Think chat agent framework. image: https://developers.cloudflare.com/dev-products-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/agents/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) # Configuration Think is configured by overriding methods and properties on your `Think` subclass. Most agents only override `getModel()`. ## Configuration overrides | Method / Property | Default | Description | | ------------------------ | ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | getModel() | throws | Return the LanguageModel to use | | getSystemPrompt() | "You are a helpful assistant." | System prompt (fallback when no context blocks) | | getTools() | {} | AI SDK ToolSet for the agentic loop | | getScheduledTasks() | {} | Code-declared recurring prompts or handlers — refer to [Scheduled tasks](https://developers.cloudflare.com/agents/harnesses/think/scheduled-tasks/) | | getDefaultTimezone() | undefined | Default timezone for wall-clock scheduled tasks | | getMessengers() | {} | Messenger ingress and delivery declarations — refer to [Messengers](https://developers.cloudflare.com/agents/harnesses/think/messengers/) | | maxSteps | 10 | Max tool-call rounds per turn | | sendReasoning | true | Send reasoning chunks to chat clients | | configureSession() | identity | Add context blocks, compaction, search, skills — refer to [Sessions](https://developers.cloudflare.com/agents/runtime/lifecycle/sessions/) | | getSkills() | \[\] | Return Agent Skills sources for on-demand skill activation — refer to [Agent Skills](https://developers.cloudflare.com/agents/runtime/execution/agent-skills/) | | getSkillScriptRunner() | null | Enable the optional run\_skill\_script tool | | workspaceBash | true | Include or configure the default workspace bash tool — refer to [Tools](https://developers.cloudflare.com/agents/harnesses/think/tools/) | | messageConcurrency | "queue" | How overlapping submits behave — refer to [Client tools](https://developers.cloudflare.com/agents/harnesses/think/client-tools/#message-concurrency) | | waitForMcpConnections | false | Wait for MCP servers before inference | | chatRecovery | true | Wrap WebSocket, sub-agent, programmatic, and continuation turns in runFiber for durable execution. Set to { maxAttempts, stableTimeoutMs, terminalMessage, onExhausted } to tune bounded recovery | | chatStreamStallTimeoutMs | 0 (off) | Opt-in inactivity watchdog: abort a turn whose model stream produces no chunk for this long (measures the gap between chunks, including tool execution). With chatRecovery on, a stall routes into bounded recovery | For `chatRecovery` and `chatStreamStallTimeoutMs` behavior, refer to [Durable recovery](https://developers.cloudflare.com/agents/harnesses/think/recovery/). ## Dynamic configuration Think's class generics match `Agent`. Persisted runtime configuration is typed at the `configure()` and `getConfig()` call sites, stored in SQLite, and survives hibernation and restarts. * [ JavaScript ](#tab-panel-4986) * [ TypeScript ](#tab-panel-4987) JavaScript ``` export class MyAgent extends Think { getModel() { const tier = this.getConfig()?.modelTier ?? "fast"; const models = { fast: "@cf/moonshotai/kimi-k2.6", capable: "@cf/meta/llama-4-scout-17b-16e-instruct", }; return createWorkersAI({ binding: this.env.AI })(models[tier]); } } ``` TypeScript ``` type MyConfig = { modelTier: "fast" | "capable"; theme: string }; export class MyAgent extends Think { getModel() { const tier = this.getConfig()?.modelTier ?? "fast"; const models = { fast: "@cf/moonshotai/kimi-k2.6", capable: "@cf/meta/llama-4-scout-17b-16e-instruct", }; return createWorkersAI({ binding: this.env.AI })(models[tier]); } } ``` | Method | Description | | ------------------------- | ------------------------------------------------------------- | | configure(config: T) | Persist a typed configuration object | | getConfig(): T \| null | Read the persisted configuration, or null if never configured | Expose configuration to the client via `@callable`: * [ JavaScript ](#tab-panel-4988) * [ TypeScript ](#tab-panel-4989) JavaScript ``` import { callable } from "agents"; export class MyAgent extends Think { getModel() { /* ... */ } @callable() updateConfig(config) { this.configure(config); } } ``` TypeScript ``` import { callable } from "agents"; export class MyAgent extends Think { getModel() { /* ... */ } @callable() updateConfig(config: MyConfig) { this.configure(config); } } ``` ## Session integration Think stores conversations in a [Session](https://developers.cloudflare.com/agents/runtime/lifecycle/sessions/) — the storage layer that holds your messages and gives the model writable memory. Two concepts come up here: **context blocks** are labelled sections of the system prompt the model can read and update (for example, a `memory` block of facts about the user), and **compaction** summarizes older messages so long conversations stay within the model's context window. Override `configureSession` to add persistent memory, compaction, search, and skills: * [ JavaScript ](#tab-panel-4990) * [ TypeScript ](#tab-panel-4991) JavaScript ``` import { Think, Session } from "@cloudflare/think"; export class MyAgent extends Think { getModel() { /* ... */ } configureSession(session) { return session .withContext("soul", { provider: { get: async () => "You are a helpful coding assistant." }, }) .withContext("memory", { description: "Important facts learned during conversation.", maxTokens: 2000, }) .withCachedPrompt(); } } ``` TypeScript ``` import { Think, Session } from "@cloudflare/think"; export class MyAgent extends Think { getModel() { /* ... */ } configureSession(session: Session) { return session .withContext("soul", { provider: { get: async () => "You are a helpful coding assistant." }, }) .withContext("memory", { description: "Important facts learned during conversation.", maxTokens: 2000, }) .withCachedPrompt(); } } ``` When `configureSession` adds context blocks, Think builds the system prompt from those blocks instead of using `getSystemPrompt()`. Think's `this.messages` getter reads directly from Session's tree-structured storage. For the full Session API — context blocks, compaction, search, skills, and multi-session support — refer to the [Sessions documentation](https://developers.cloudflare.com/agents/runtime/lifecycle/sessions/). ## Package exports | Export | Description | | ------------------------------------- | ----------------------------------------------------------- | | @cloudflare/think | Think, Session, Workspace, skills namespace | | @cloudflare/think/messengers | Messenger contracts, Chat SDK bridge, state agent, delivery | | @cloudflare/think/messengers/telegram | Telegram messenger provider and delivery helpers | | @cloudflare/think/workflows | ThinkWorkflow, step.prompt() — Workflow prompts | | @cloudflare/think/tools/workspace | createWorkspaceTools() — for custom storage backends | | @cloudflare/think/tools/execute | createExecuteTool() — sandboxed code execution via codemode | | @cloudflare/think/tools/browser | createBrowserTools() — Chrome DevTools Protocol tools | | @cloudflare/think/tools/extensions | createExtensionTools() — LLM-driven extension loading | | @cloudflare/think/extensions | ExtensionManager, HostBridgeLoopback — extension runtime | ## Dependencies Peer dependencies you provide: | Package | Required | Notes | | ---------------------- | -------- | -------------------------------- | | agents | yes | Cloudflare Agents SDK | | ai | yes | AI SDK v6 | | zod | yes | Schema validation (v4) | | @chat-adapter/telegram | optional | Required for Telegram messengers | Bundled with `@cloudflare/think`: | Package | Notes | | -------------------- | --------------------------------------------------- | | @cloudflare/shell | Workspace filesystem | | @cloudflare/codemode | Code execution for createExecuteTool() | | just-bash | Sandboxed shell for the default workspace bash tool | The Agent Skills engine and its script runner live in [agents/skills](https://developers.cloudflare.com/agents/runtime/execution/agent-skills/), so skill scripts pull `@cloudflare/worker-bundler` and `just-bash` through `agents`, not Think. ```json {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/agents/","name":"Agents"}},{"@type":"ListItem","position":3,"item":{"@id":"/agents/harnesses/","name":"Harnesses"}},{"@type":"ListItem","position":4,"item":{"@id":"/agents/harnesses/think/","name":"Think"}},{"@type":"ListItem","position":5,"item":{"@id":"/agents/harnesses/think/configuration/","name":"Configuration"}}]} ```