OAuth 2.0 Provider Guide

Chainabit acts as an OAuth 2.0 Authorization Server (AS). Your application can request delegated access to Chainabit resources on behalf of a user — for example, triggering AI runs or reading wallet balances — without ever handling the user's Chainabit credentials.

Supported Capabilities

Feature	Supported
Authorization Code + PKCE	✅
Refresh token rotation	✅
Token revocation (`/oauth/revoke`)	✅
OpenID Connect UserInfo (`/oauth/userinfo`)	✅
OIDC Auto-Discovery (`/.well-known/openid-configuration`)	✅
Implicit flow	❌
Client credentials	❌
Device code	❌
`plain` PKCE	❌

PKCE with S256 is mandatory for all clients, including confidential ones.

Scopes

Scope	What it grants
`execution:run`	Trigger AI executions on the user's behalf
`wallet:read`	Read the user's Chainabit wallet balance

Request only the scopes your application actually needs.

Full Authorization Flow

Step 1 — Generate PKCE Parameters

Generate a code_verifier and derive the code_challenge before redirecting the user.

javascript

import { createHash, randomBytes } from 'crypto';

function generatePKCE() {
  const codeVerifier = randomBytes(48).toString('base64url'); // 64 chars
  const codeChallenge = createHash('sha256')
    .update(codeVerifier)
    .digest('base64url');
  return { codeVerifier, codeChallenge };
}

const { codeVerifier, codeChallenge } = generatePKCE();
const state = randomBytes(16).toString('hex'); // CSRF state
// Store codeVerifier and state securely — session, cookie, etc.

Step 2 — Redirect to Authorization Endpoint

GET https://api.chainabit.com/api/v1/oauth/authorize
  ?client_id=<your-client-id>
  &redirect_uri=https://yourapp.com/oauth/callback
  &response_type=code
  &scope=execution:run%20wallet:read
  &state=<random-state>
  &code_challenge=<base64url-sha256-of-verifier>
  &code_challenge_method=S256

Query Parameters

Parameter	Required	Description
`client_id`	Yes	Your OAuth client UUID, issued by Chainabit
`redirect_uri`	Yes	Must exactly match a registered redirect URI
`response_type`	Yes	Always `code`
`scope`	Yes	Space-separated list of scopes
`state`	Recommended	Random value you generate; returned unchanged in callback
`code_challenge`	Yes	`BASE64URL(SHA-256(code_verifier))`
`code_challenge_method`	Yes	Always `S256`

Chainabit displays a login page to the user. The user authenticates (email+password or magic link) and then reviews the consent page showing which scopes your application is requesting.

Step 3 — Handle the Callback

After the user approves, Chainabit redirects to your redirect_uri:

https://yourapp.com/oauth/callback?code=<authorization-code>&state=<your-state>

Always verify state matches what you sent to prevent CSRF.

If the user denies:

https://yourapp.com/oauth/callback?error=access_denied&state=<your-state>

Step 4 — Exchange Code for Tokens

bash

curl -X POST https://api.chainabit.com/api/v1/oauth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -u "<client-id>:<client-secret>" \
  -d "grant_type=authorization_code" \
  -d "code=<authorization-code>" \
  -d "redirect_uri=https://yourapp.com/oauth/callback" \
  -d "code_verifier=<your-code-verifier>"

For public clients (no secret), omit the -u flag and pass client_id in the body:

bash

curl -X POST https://api.chainabit.com/api/v1/oauth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=authorization_code" \
  -d "client_id=<client-id>" \
  -d "code=<authorization-code>" \
  -d "redirect_uri=https://yourapp.com/oauth/callback" \
  -d "code_verifier=<your-code-verifier>"

Request Body

Field	Required	Description
`grant_type`	Yes	`authorization_code`
`code`	Yes	The authorization code from the callback
`redirect_uri`	Yes	Must exactly match the value used in Step 2
`code_verifier`	Yes	The original verifier you generated in Step 1
`client_id`	Conditional	Required if not using HTTP Basic auth

Token Response

json

{
  "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 3600,
  "refresh_token": "v1_base64url_opaque_token...",
  "scope": "execution:run wallet:read"
}

Field	Type	Description
`access_token`	`string`	JWT — send as `Authorization: Bearer <token>`
`token_type`	`string`	Always `Bearer`
`expires_in`	`number`	Seconds until access token expires (3600)
`refresh_token`	`string`	Opaque long-lived token — store securely server-side
`scope`	`string`	Space-separated list of granted scopes

Step 5 — Use the Access Token

Include the access token as a bearer token on Chainabit API requests:

bash

# Read wallet balance (requires wallet:read scope)
curl https://api.chainabit.com/api/v1/wallet/me \
  -H "Authorization: Bearer <access-token>"

# Trigger an AI run (requires execution:run scope)
curl -X POST https://api.chainabit.com/api/v1/features/chat/runs \
  -H "Authorization: Bearer <access-token>" \
  -H "Content-Type: application/json" \
  -d '{"messages": [{"role": "user", "content": "Hello!"}]}'

Step 6 — Refresh the Access Token

Access tokens expire after 3600 seconds. Use the refresh token to obtain a new one.

bash

curl -X POST https://api.chainabit.com/api/v1/oauth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -u "<client-id>:<client-secret>" \
  -d "grant_type=refresh_token" \
  -d "refresh_token=<current-refresh-token>"

Response

Same shape as the initial token response — a new refresh_token is always returned. Discard the old refresh token immediately and store the new one.

Refresh Token Rotation

Chainabit rotates refresh tokens on every use. If you attempt to reuse a consumed refresh token, Chainabit revokes the entire token family, invalidating all tokens for that grant. You must then restart the authorization flow.

Revoke a Token

Revoke an access or refresh token when the user disconnects your application:

bash

curl -X POST https://api.chainabit.com/api/v1/oauth/revoke \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -u "<client-id>:<client-secret>" \
  -d "token=<token-to-revoke>" \
  -d "token_type_hint=refresh_token"

Revoking a refresh token also revokes its entire rotation family. The endpoint always returns 200 OK, even for unknown tokens (per RFC 7009).

UserInfo Endpoint

Retrieve basic profile data for the authenticated user:

bash

curl https://api.chainabit.com/api/v1/oauth/userinfo \
  -H "Authorization: Bearer <access-token>"

Response

The payload is deterministic for the granted scopes:

sub is always present
email and email_verified require email:read
name and preferred_username require profile:read
wallet data, internal account IDs, admin metadata, and security metadata are never exposed here

json

{
  "sub": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "email": "[email protected]",
  "email_verified": true,
  "name": "Alice Smith",
  "preferred_username": "alice"
}

Field	Type	Notes
`sub`	`string`	Stable Chainabit user UUID — use as your user identifier
`email`	`string`	Present only when `email:read` was granted
`email_verified`	`boolean`	Present only when `email:read` was granted
`name`	`string \| null`	Present only when `profile:read` was granted
`preferred_username`	`string \| null`	Present only when `profile:read` was granted

Error Reference

Token endpoint errors

HTTP	Error	Meaning
`400`	`unsupported_grant_type`	`grant_type` is not `authorization_code` or `refresh_token`
`400`	`invalid_grant`	Code expired, already used, `redirect_uri` mismatch, or PKCE verification failed
`400`	`invalid_request`	Missing required parameter or malformed `code_verifier`
`401`	`invalid_client`	Client authentication failed (wrong secret)

Authorization errors (redirect)

Error	When
`access_denied`	User explicitly denied the authorization request

Security Best Practices

HTTPS only — Use HTTPS for all redirect URIs and token exchanges in production.
Never log tokens — Do not log authorization codes, access tokens, refresh tokens, PKCE verifiers, or client secrets.
Store refresh tokens server-side — Treat them as long-lived secrets; never expose them to browser JavaScript.
Verify state — Always validate the state parameter in your callback handler.
Minimal scope — Request only the scopes you actually use.
Rotate immediately — Store the new refresh token as soon as you receive it; never attempt to reuse a consumed token.

Client Registration

OAuth clients are provisioned by Chainabit partner admins using the CLI:

bash

chainabit partner oauth-client create \
  --name "My App" \
  --type confidential \
  --redirect-uri https://yourapp.com/oauth/callback \
  --scope execution:run \
  --scope wallet:read

Contact your Chainabit partner account manager to get partner API key access for client management.

Auto-Discovery (OIDC / RFC 8414)

Chainabit exposes a standard Authorization Server Metadata document. Clients that support auto-discovery can point at the issuer URL and retrieve all endpoint addresses automatically — no manual endpoint configuration needed.

Discovery Document URLs

GET https://api.chainabit.com/.well-known/openid-configuration

An identical document is also available at the RFC 8414 canonical path:

GET https://api.chainabit.com/.well-known/oauth-authorization-server

Both endpoints are public, cacheable (Cache-Control: public, max-age=3600), and return Access-Control-Allow-Origin: *.

Supabase Custom Auth — Auto-Discovery Mode

When configuring Chainabit as a Custom Auth Provider in Supabase:

Select Configuration Method: Auto-discovery.
Set Issuer URL to https://api.chainabit.com (no path, no trailing slash).
Supabase fetches https://api.chainabit.com/.well-known/openid-configuration automatically.
All endpoint URLs (authorize, token, userinfo, revoke) are populated from the discovery document.

Chainabit issues OAuth 2.0 access tokens, not OIDC ID tokens. Supabase uses the userinfo_endpoint to verify the user's identity after the authorization code exchange. Register your OAuth client with profile:read and email:read scopes.

Discovery Document Fields

Field	Value
`response_types_supported`	`["code"]`
`grant_types_supported`	`["authorization_code", "refresh_token"]`
`token_endpoint_auth_methods_supported`	`["client_secret_basic", "none"]`
`code_challenge_methods_supported`	`["S256"]`
`scopes_supported`	`email:read`, `profile:read`, `execution:run`, `wallet:read`
`subject_types_supported`	`["public"]`
`claims_supported`	`sub`, `email`, `email_verified`, `name`, `preferred_username`

jwks_uri and id_token_signing_alg_values_supported are intentionally absent — Chainabit uses symmetric signing and does not issue ID tokens.

OAuth 2.0 Provider Guide ​

Supported Capabilities ​

Scopes ​

Full Authorization Flow ​

Step 1 — Generate PKCE Parameters ​

Step 2 — Redirect to Authorization Endpoint ​

Query Parameters ​

Step 3 — Handle the Callback ​

Step 4 — Exchange Code for Tokens ​

Request Body ​

Token Response ​

Step 5 — Use the Access Token ​

Step 6 — Refresh the Access Token ​

Response ​

Revoke a Token ​

UserInfo Endpoint ​

Response ​

Error Reference ​

Token endpoint errors ​

Authorization errors (redirect) ​

Security Best Practices ​

Client Registration ​

Auto-Discovery (OIDC / RFC 8414) ​

Discovery Document URLs ​

Supabase Custom Auth — Auto-Discovery Mode ​

Discovery Document Fields ​

OAuth 2.0 Provider Guide

Supported Capabilities

Scopes

Full Authorization Flow

Step 1 — Generate PKCE Parameters

Step 2 — Redirect to Authorization Endpoint

Query Parameters

Step 3 — Handle the Callback

Step 4 — Exchange Code for Tokens

Request Body

Token Response

Step 5 — Use the Access Token

Step 6 — Refresh the Access Token

Response

Revoke a Token

UserInfo Endpoint

Response

Error Reference

Token endpoint errors

Authorization errors (redirect)

Security Best Practices

Client Registration

Auto-Discovery (OIDC / RFC 8414)

Discovery Document URLs

Supabase Custom Auth — Auto-Discovery Mode

Discovery Document Fields