tools-only OAuth 2.0 Flows Reference
Complete guide to OAuth flows supported by Salesforce Connected Apps and External Client Apps.
Flow Decision Matrix
| Use Case | Recommended Flow | PKCE | Refresh Token | Secret Required |
|---|---|---|---|---|
| Web Server (backend) | Authorization Code | Optional | Yes | Yes |
| Single Page App (SPA) | Authorization Code | Required | Yes (rotate) | No |
| Mobile Native App | Authorization Code | Required | Yes (rotate) | No |
| Server-to-Server | JWT Bearer | N/A | No | Certificate |
| CI/CD Pipeline | JWT Bearer | N/A | No | Certificate |
| IoT/Device | Device Authorization | N/A | Yes | No |
| CLI Tool | Device Authorization | N/A | Yes | No |
| Legacy (avoid) | Username-Password | N/A | Yes | Yes |
Authorization Code Flow
Best for: Web applications, Mobile apps, SPAs
Flow Diagram
┌──────────┐ ┌───────────────┐ ┌────────────────┐
│ User │ │ Application │ │ Salesforce │
└────┬─────┘ └───────┬───────┘ └───────┬────────┘
│ │ │
│ 1. Click Login │ │
│───────────────────>│ │
│ │ │
│ │ 2. Redirect to │
│ │ /authorize │
│<───────────────────┼─────────────────────>│
│ │ │
│ 3. Login & Consent│ │
│─────────────────────────────────────────>│
│ │ │
│ │ 4. Redirect with │
│<───────────────────┼──────code───────────│
│ │ │
│ │ 5. Exchange code │
│ │ for tokens │
│ │─────────────────────>│
│ │ │
│ │ 6. Access Token + │
│ │ Refresh Token │
│ │<─────────────────────│
│ │ │
│ 7. Authenticated │ │
│<───────────────────│ │
Authorization URL
https://login.salesforce.com/services/oauth2/authorize
?response_type=code
&client_id=<CONSUMER_KEY>
&redirect_uri=<CALLBACK_URL>
&scope=api refresh_token
&state=<CSRF_TOKEN>
&code_challenge=<PKCE_CHALLENGE> # For PKCE
&code_challenge_method=S256 # For PKCE
Token Exchange
curl -X POST https://login.salesforce.com/services/oauth2/token \
-d "grant_type=authorization_code" \
-d "code=<AUTH_CODE>" \
-d "client_id=<CONSUMER_KEY>" \
-d "client_secret=<CONSUMER_SECRET>" \
-d "redirect_uri=<CALLBACK_URL>" \
-d "code_verifier=<PKCE_VERIFIER>" # For PKCE
JWT Bearer Flow
Best for: Server-to-server integrations, CI/CD, Headless automation
Prerequisites
- X.509 Certificate uploaded to Salesforce
- Connected App with certificate configured
- Pre-authorized user via Permission Set
Flow Diagram
┌─────────────────┐ ┌────────────────┐
│ Server/CI/CD │ │ Salesforce │
└────────┬────────┘ └───────┬────────┘
│ │
│ 1. Create JWT with claims │
│ - iss: consumer_key │
│ - sub: username │
│ - aud: login.salesforce.com │
│ - exp: expiration │
│ │
│ 2. Sign JWT with private key │
│ │
│ 3. POST to /token │
│─────────────────────────────────>│
│ │
│ 4. Validate signature with │
│ uploaded certificate │
│ │
│ 5. Access Token │
│<─────────────────────────────────│
JWT Structure
// Header
{
"alg": "RS256"
}
// Payload
{
"iss": "<CONSUMER_KEY>",
"sub": "user@company.com",
"aud": "https://login.salesforce.com",
"exp": 1234567890
}
Token Request
curl -X POST https://login.salesforce.com/services/oauth2/token \
-d "grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer" \
-d "assertion=<SIGNED_JWT>"
Client Credentials Flow
Best for: Service accounts, Background processes
Configuration
- Enable
isClientCredentialsEnabledin ECA OAuth Settings - Assign execution user via Permission Set
Token Request
curl -X POST https://login.salesforce.com/services/oauth2/token \
-d "grant_type=client_credentials" \
-d "client_id=<CONSUMER_KEY>" \
-d "client_secret=<CONSUMER_SECRET>"
Device Authorization Flow
Best for: CLI tools, Smart TVs, IoT devices without browsers
Flow Diagram
┌─────────────┐ ┌───────────────┐ ┌────────────────┐
│ Device │ │ User │ │ Salesforce │
└──────┬──────┘ └───────┬───────┘ └───────┬────────┘
│ │ │
│ 1. Request device code│ │
│─────────────────────────────────────────────────>│
│ │ │
│ 2. device_code + user_code + verification_uri │
│<─────────────────────────────────────────────────│
│ │ │
│ 3. Display code │ │
│───────────────────────>│ │
│ │ │
│ │ 4. Visit URL & enter │
│ │ user_code │
│ │────────────────────────>│
│ │ │
│ 5. Poll for token │ │
│─────────────────────────────────────────────────>│
│ │ │
│ 6. Access Token (when authorized) │
│<─────────────────────────────────────────────────│
Device Code Request
curl -X POST https://login.salesforce.com/services/oauth2/device/code \
-d "client_id=<CONSUMER_KEY>" \
-d "scope=api refresh_token"
Poll for Token
curl -X POST https://login.salesforce.com/services/oauth2/token \
-d "grant_type=device" \
-d "client_id=<CONSUMER_KEY>" \
-d "code=<DEVICE_CODE>"
Refresh Token Flow
Use: Exchange refresh token for new access token
curl -X POST https://login.salesforce.com/services/oauth2/token \
-d "grant_type=refresh_token" \
-d "client_id=<CONSUMER_KEY>" \
-d "client_secret=<CONSUMER_SECRET>" \
-d "refresh_token=<REFRESH_TOKEN>"
PKCE (Proof Key for Code Exchange)
Required for: Mobile apps, SPAs, Public clients
Generate Code Verifier & Challenge
// Generate random code verifier (43-128 chars)
const codeVerifier = base64URLEncode(crypto.randomBytes(32));
// Create code challenge
const codeChallenge = base64URLEncode(
crypto.createHash('sha256').update(codeVerifier).digest()
);
Use in Authorization
/authorize?...&code_challenge=<CHALLENGE>&code_challenge_method=S256
Use in Token Exchange
grant_type=authorization_code&...&code_verifier=<VERIFIER>
Token Introspection
Use: Validate token status and metadata
curl -X POST https://login.salesforce.com/services/oauth2/introspect \
-d "token=<ACCESS_TOKEN>" \
-d "client_id=<CONSUMER_KEY>" \
-d "client_secret=<CONSUMER_SECRET>" \
-d "token_type_hint=access_token"
Token Revocation
Use: Invalidate tokens on logout
curl -X POST https://login.salesforce.com/services/oauth2/revoke \
-d "token=<TOKEN>"
Best Practices
- Always use HTTPS for callback URLs in production
- Enable PKCE for all public clients (mobile, SPA)
- Use short-lived access tokens with refresh token rotation
- Store secrets securely - never in client-side code
- Implement state parameter to prevent CSRF
- Validate tokens before trusting claims
- Use JWT Bearer for server-to-server instead of username-password