OAuth for AI Agents: A Complete Implementation Guide
OAuth was not designed for AI agents, but it is still the dominant auth protocol. Here is how to implement it correctly for autonomous agent workflows.
Every useful AI agent eventually needs to authenticate with external services. Your agent wants to send emails through Gmail, create issues on GitHub, post messages to Slack, or update records in Salesforce. All of these use OAuth 2.0. If your agent can't handle OAuth, it's limited to services with simple API keys, and that pool is shrinking.
OAuth 2.0 flows for agents
OAuth 2.0 defines several authorization flows, each for different client types. For AI agents, two matter.
The **Authorization Code flow** is the standard browser-based flow. A human clicks "Connect to Gmail," gets redirected to Google, approves the permissions, and gets sent back with an authorization code. Your application exchanges this code for access and refresh tokens. This flow requires human interaction exactly once, during initial setup.
The **Client Credentials flow** is for machine-to-machine communication. No human needed. Your agent authenticates directly with the service using a client ID and secret. This works for services where the agent acts as itself (not on behalf of a user), like accessing a company-wide API or internal service.
For most OpenClaw agents, the pattern is: Authorization Code flow once to get initial tokens during setup, then refresh tokens for ongoing access. The human authorizes once, the agent maintains access from there.
Token storage and security
Where you store OAuth tokens matters a lot. Access tokens are short-lived (usually 1 hour) and relatively low-risk. Refresh tokens are long-lived (often indefinite) and high-risk. A stolen refresh token gives an attacker ongoing access to the connected service.
Don't store tokens in environment variables, configuration files, or agent memory. These locations are readable by skills, visible in logs, and often backed up to insecure storage. Tokens belong in an encrypted credential store with access control.
ClawCoil provides this store as a core service. Tokens are encrypted at rest with AES-256, decrypted only in memory during use, and accessible only to skills with explicit permission. The encryption key is derived from your agent's identity certificate, so tokens encrypted for one agent can't be decrypted by another.
Handling token refresh
The most common OAuth failure in production agents is expired tokens. An access token expires, the skill that needs it doesn't handle the 401 response, and the agent starts returning errors for every task that touches that service.
Proactive refresh is the fix. Instead of waiting for a token to expire and handling the error, refresh it before it expires. If an access token has a 3600-second lifetime, refresh it at 3000 seconds. This eliminates the window where an expired token can cause a failure.
ClawCoil runs a background refresh scheduler that monitors token expiry across all connected services. When a token approaches expiry, ClawCoil refreshes it proactively. Skills always get valid tokens without needing to handle refresh logic themselves.
Multi-tenant considerations
If your agent serves multiple users, each with their own connected accounts, token management complexity multiplies. Each user has their own set of tokens for each connected service. Token refresh schedules are independent. Permission scopes may differ between users.
ClawCoil handles multi-tenant token management natively. Each user's tokens are stored in an isolated namespace, encrypted with user-specific keys. Skills request tokens by user context, and ClawCoil returns the correct credentials without the skill needing to know which user it's serving. This keeps multi-tenant auth simple for skill developers while maintaining strong isolation.