# flue | Astro | Knowledge Base | Instagit

The sandbox agent framework.

GitHub Stars: 3.2k

Repository: https://github.com/withastro/flue

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## Articles

### [How to Use Event Callbacks for Monitoring and Debugging Agent Execution in Flue](/withastro/flue/using-event-callbacks-monitoring-debugging-agent-execution)

Learn to monitor and debug agent execution in Flue using event callbacks subscribeEvent and setEventCallback for comprehensive insight into your agent's lifecycle.

- Tags: how-to-guide
- Published: 2026-05-11

### [Orchestrating Multiple Agents in Flue: Task Sessions and Parent-Child Relationships Explained](/withastro/flue/orchestrating-multiple-agents-task-sessions-parent-child-relationships)

Master orchestrating multiple agents in Flue with task sessions and parent-child relationships. Build complex, parallel multi-agent workflows with isolated sessions and secure communication.

- Tags: deep-dive
- Published: 2026-05-11

### [Configuring Multiple Model Providers with Provider-Specific Settings in Flue](/withastro/flue/configuring-multiple-model-providers-provider-specific-settings)

Configure multiple LLM model providers with Flue's registerProvider and configureProvider. Route traffic to local Ollama, custom gateways, or Cloudflare Workers AI without rebuilding.

- Tags: how-to-guide
- Published: 2026-05-11

### [Mounting Cloudflare R2 Buckets as Read-Only Knowledge Base Filesystems with Flue](/withastro/flue/mounting-cloudflare-r2-buckets-read-only-knowledge-base-filesystems)

Mount Cloudflare R2 buckets as read-only knowledge base filesystems with Flue. Combine SQLite Durable Objects and R2 binding for tool-based search operations.

- Tags: how-to-guide
- Published: 2026-05-11

### [Handling Errors, Timeouts, and Retries in Flue Agent Operations](/withastro/flue/handling-errors-timeouts-retries-flue-agent-operations)

Learn how to handle errors timeouts and retries in Flue agent operations withastro/flue. Discover FlueError hierarchy AbortSignal and automatic retries for LLM calls.

- Tags: how-to-guide
- Published: 2026-05-11

### [How to Integrate the Daytona Connector for Full Linux Container Sandboxes in Flue](/withastro/flue/integrating-daytona-connector-full-linux-container-sandboxes)

Integrate the Daytona connector with Flue to run commands in isolated Linux containers. Enhance your agent's capabilities beyond the default Bash environment today.

- Tags: how-to-guide
- Published: 2026-05-11

### [Configuring Build Targets for Node.js and Cloudflare Workers Deployment in Flue](/withastro/flue/configuring-build-targets-nodejs-cloudflare-workers-deployment)

Configure build targets for Node.js and Cloudflare Workers with Flue using the --target flag. Deploy identical agent code to both runtimes effortlessly. Learn how now.

- Tags: how-to-guide
- Published: 2026-05-11

### [Organizing Flue Agents: .flue Directory Layout vs Root-Level Layout](/withastro/flue/organizing-agents-flue-directory-layout-vs-root-level-layout)

Discover Flue's agent organization options: master `.flue` directory layout versus root-level `agents` and `roles` folders. Optimize your project structure effortlessly.

- Tags: architecture
- Published: 2026-05-11

### [Implementing Custom Session Stores for Persistent Conversation State in Flue](/withastro/flue/implementing-custom-session-stores-persistent-conversation-state-flue)

Learn to implement custom session stores in Flue to persist conversation state across server restarts. Override save load and delete methods with the SessionStore interface.

- Tags: how-to-guide
- Published: 2026-05-11

### [Using Valibot Schemas for Validating and Typing Agent Responses in Flue](/withastro/flue/using-valibot-schemas-validating-typing-agent-responses)

Leverage Valibot schemas in Flue to validate and type LLM agent responses, ensuring robust and predictable outputs. Convert schemas to tool definitions and parse responses with safeParse for typed validation.

- Tags: how-to-guide
- Published: 2026-05-11

### [Implementing Server-Sent Events Streaming for Real-Time Agent Output in Flue](/withastro/flue/implementing-server-sent-events-streaming-real-time-agent-output)

Implement Server-Sent Events streaming in Flue for real-time LLM output monitoring. Stream agent events and results over HTTP, eliminating the need for polling and enhancing your application's responsiveness.

- Tags: tutorial
- Published: 2026-05-11

### [Using the Flue Local Sandbox in CI/CD Environments with Host Filesystem Access](/withastro/flue/using-local-sandbox-ci-cd-environments-host-filesystem-access)

Unlock Flue local sandbox capabilities in CI/CD. Access host filesystem directly, read repo files, and write artifacts with Node.js fs/promises API, eliminating virtual layer overhead.

- Tags: how-to-guide
- Published: 2026-05-11

### [Relationship Between Agent Instances, Harnesses, and Sessions in Flue](/withastro/flue/agent-instances-harnesses-sessions-relationship-flue)

Understand the relationship between agent instances, harnesses, and sessions in Flue. Learn how Flue manages conversation state, tools, and task history for isolated sessions.

- Tags: internals
- Published: 2026-05-11

### [Message Compaction for Optimizing Conversation History in Long-Running Flue Agents](/withastro/flue/message-compaction-optimizing-conversation-history-long-running-agents)

Optimize long-running Flue agents with message compaction. Automatically summarize conversation history, prevent memory growth, and reduce token costs for efficient AI interactions.

- Tags: performance
- Published: 2026-05-11

### [How to Implement Abort Signals for Cancelling Long-Running Agent Operations in Flue](/withastro/flue/implementing-abort-signals-cancelling-long-running-agent-operations-flue)

Learn to implement abort signals in Flue to cancel long-running agent operations. Master timeouts, manual triggers, and composite controllers for efficient async call management.

- Tags: how-to-guide
- Published: 2026-05-11

### [Task Tool for Child Agent Delegation with Separate Working Directories](/withastro/flue/task-tool-child-agent-delegation-separate-working-directories)

Flue's task tool delegates child agents to separate working directories for sandboxed operations and independent contexts. Execute recursive workflows without parent contamination.

- Tags: how-to-guide
- Published: 2026-05-11

### [Creating and Using Skills for Agent Task Automation in Flue: A Complete Guide](/withastro/flue/creating-using-skills-agent-task-automation-flue)

Master agent task automation in Flue by creating and using skills. Learn how to implement reusable markdown workflows and invoke them with session skill for efficient LLM tool integration.

- Tags: how-to-guide
- Published: 2026-05-11

### [Role Precedence Rules in Flue: Harness, Session, and Call Levels Explained](/withastro/flue/role-precedence-rules-flue-harness-session-call-levels)

Understand Flue's role precedence rules at the harness, session, and call levels. Discover how the narrowest scope, call-level, always wins for precise control.

- Tags: deep-dive
- Published: 2026-05-11

### [Defining and Registering Custom Tools for LLM Agents Using the ToolDef Interface](/withastro/flue/defining-registering-custom-tools-llm-agents-tooldef-interface)

Learn how to define and register custom tools for LLM agents using Flue's ToolDef interface. Easily integrate deterministic functions with JSON Schema parameters and async logic into your agent's workflow.

- Tags: tutorial
- Published: 2026-05-11

### [Flue Sandbox Types: Virtual, Local, and Container (Daytona) Explained](/withastro/flue/flue-sandbox-types-differences-virtual-local-container-daytona)

Explore Flue sandbox types: Virtual, Local, and Container (Daytona). Understand their distinct isolation levels for secure execution in your projects. Learn more today.

- Tags: deep-dive
- Published: 2026-05-11

### [Connecting Remote MCP Servers to Flue Agents with Authentication](/withastro/flue/connecting-remote-mcp-servers-flue-agents-authentication)

Easily connect remote MCP servers to Flue agents using the connectMcpServer helper. Secure your connections with bearer tokens and inject tools into your agent harness.

- Tags: how-to-guide
- Published: 2026-05-11

### [How to Configure Enterprise API Gateways with Custom Base URLs and Authentication Headers in Flue](/withastro/flue/configuring-enterprise-api-gateways-custom-base-urls-authentication-headers-flue)

Learn to configure enterprise API gateways in Flue. Easily set custom base URLs and authentication headers using registerProvider and configureProvider for robust API management.

- Tags: how-to-guide
- Published: 2026-05-11

### [Session Persistence Differences: Cloudflare Durable Objects vs Node.js In-Memory Stores in Flue](/withastro/flue/session-persistence-differences-cloudflare-durable-objects-vs-nodejs-in-memory-stores)

Compare Cloudflare Durable Objects with Node.js in-memory stores for session persistence in Flue. Discover edge SQLite vs in-memory Maps and their restart implications.

- Tags: comparison
- Published: 2026-05-11