In This Article
Introduction
OpenClaw's power comes from connecting to your systems. Whether you're pulling data from a CRM, receiving webhooks from a support tool, or building a custom Skill, API integration is core. Here's what we're covering: REST APIs, webhooks, and authentication patterns for developers. See Skills explained for the extension model.
Integration patterns fall into two categories: outbound (OpenClaw calls your APIs) and inbound (external systems push events to OpenClaw). Most production deployments use both. We'll cover each with concrete examples.
REST API Integration
OpenClaw can call REST APIs via Skills. Many integrations use a generic HTTP Skill: specify URL, method, headers. For repeated calls, build a custom Skill that encapsulates your API's logic. Store base URLs and endpoints in config; keep credentials in environment variables.
HTTP Skill. The built-in HTTP Skill (or equivalent on ClawHub) lets the agent make arbitrary REST calls. You configure allowed domains and methods. The agent can call GET, POST, etc. Useful for one-off integrations; less ideal for complex APIs with many endpoints.
Custom Skill pattern. For production, build a Skill that exposes domain-specific tools. Example: a Salesforce Skill exposes getContact(id), updateOpportunity(id, stage), createTask(contactId, subject). The agent reasons about when to call each; the Skill handles URL construction, error handling, and response parsing. See custom Skill guide.
Request structure. Store API base URL in config. Build full URLs in the Skill. Use consistent error handling: map 4xx/5xx to meaningful messages for the agent. The agent needs to understand when an API call failed and why.
Response handling. Parse API responses and return structured data to the agent. Don't dump raw JSON — extract the fields the agent needs. Keeps context windows manageable and improves agent reasoning.
Webhooks
For event-driven workflows, expose a webhook endpoint that receives events from your external system. The webhook handler parses the payload, creates a task for the agent, and returns 200. The agent processes asynchronously. Use for: new support tickets, CRM updates, payment events.
Webhook endpoint. OpenClaw can expose an HTTP endpoint (via a Skill or gateway extension) that receives POST requests. The handler must: validate the request (signature, if supported), parse the payload, create an agent task (e.g., add to HEARTBEAT or trigger immediate processing), return 200 quickly. Don't do heavy processing in the webhook handler — queue and process async.
Common webhook sources. Zendesk (new ticket), HubSpot (deal stage change), Stripe (payment event), GitHub (push, PR). Each has a payload format. Your handler maps the payload to an agent task: "New support ticket #12345. Customer: X. Subject: Y. Draft response."
Idempotency. Webhooks can be retried. Use idempotency keys: if you've already processed event X, return 200 without reprocessing. Prevents duplicate agent actions.
Security. Verify webhook signatures when the source supports it (Stripe, GitHub, etc.). Reject unsigned requests from untrusted sources. Use HTTPS. Don't expose webhooks without authentication for sensitive systems.
Custom Skills
For complex integrations, build a custom Skill. Each Skill exposes tools the LLM can call. Example: a Salesforce Skill exposes getContact, updateOpportunity, createTask. The agent reasons about when to call each; the Skill handles the API details.
Tool design. Each tool should do one thing well. getContact(id) not doSalesforceStuff(...). The agent reasons better with focused tools. Include clear parameter descriptions — the LLM uses these to decide when to call.
Error handling. Return structured errors: "Contact not found", "Rate limit exceeded", "Invalid stage value". The agent can reason about retries or escalation. Don't throw raw exceptions — the agent can't handle them.
Rate limiting. Respect API rate limits. Implement backoff for 429 responses. Consider caching for frequently accessed data. Document limits in your Skill so operators know what to expect.
Testing. Test Skills in isolation. Mock API responses. Verify the agent can recover from errors. Integration tests with real APIs (sandbox) before production.
Authentication
API keys: use env vars. OAuth: store tokens securely; refresh before expiry. For production, consider a secrets manager. Never log credentials. See security practices.
API keys. Store in environment variables or a secrets manager. Load at runtime. Never commit to git. Rotate regularly. Use keys with minimal required scope.
OAuth 2.0. Many APIs use OAuth. Store refresh tokens securely. Implement token refresh before expiry. The Skill should handle refresh transparently — the agent doesn't need to know. Consider using a library (e.g., axios with interceptors) for automatic refresh.
Service accounts. For server-to-server integration, use service accounts with minimal permissions. Document what the account can access. Audit access periodically.
Secrets managers. AWS Secrets Manager, HashiCorp Vault, or similar. Fetch credentials at startup or on first use. Reduces credential exposure in config files.
Implementation Checklist
- □ Identify APIs you need to integrate
- □ Obtain API credentials (read-only first)
- □ Choose: HTTP Skill for simple, or custom Skill for complex
- □ Implement authentication (keys or OAuth)
- □ Add error handling and rate limiting
- □ For inbound: set up webhook endpoint; verify signatures
- □ Test in sandbox/staging
- □ Document endpoints and limits for operators
FAQ
Does OpenClaw have a built-in API client? OpenClaw uses Skills for external calls. Use the HTTP Skill or build custom. No single built-in client for all APIs. Each integration is a Skill.
Rate limiting? Implement in your Skill. Respect API rate limits. Add retries with exponential backoff for 429s. Consider request queuing for high-volume integrations.
Can OpenClaw receive webhooks without a public URL? You need a publicly reachable endpoint for webhooks. Use a tunnel (ngrok) for local dev. For production, deploy OpenClaw behind a load balancer with a public URL, or use a webhook relay service.
What about GraphQL? Same principles. Build a Skill that makes GraphQL requests. The agent doesn't care about the protocol — it calls tools. Your Skill translates.
Wrapping Up
API integration unlocks OpenClaw's value. Start simple with the HTTP Skill; add custom Skills as you need production-grade integrations. Secure credentials, handle errors, respect rate limits. OpenClaw Consult builds production integrations for clients.