Credentials

The node uses the oidcToken credential type. Configure it in n8n under Settings → Credentials → Add Credential → OIDC.

Credential Fields

Field	Type	Required	Default	Description
OIDC Issuer	string	Conditional*	—	Base URL of the Identity Provider. Endpoints are auto-discovered via /.well-known/openid-configuration.
OIDC Token Endpoint	string	Conditional*	—	Direct token endpoint URL. Used when OIDC Issuer is not provided.
OIDC JWKS URI	string	No	—	URL of the JSON Web Key Set used to cryptographically verify token signatures. Auto-discovered when using Issuer.
OIDC Client ID	string	Yes	—	The client ID registered with the Identity Provider.
OIDC Client Secret	string (password)	Conditional**	—	The client secret. Required for Client Credentials; optional for Password (public clients).
Resource Owner Username	string	Conditional**	—	The resource owner username. Required for Password grant; ignored for Client Credentials.
Resource Owner Password	string (password)	Conditional**	—	The resource owner password. Required for Password grant; ignored for Client Credentials.

*Conditional (discovery): At least one of OIDC Issuer or OIDC Token Endpoint must be provided. If both are empty, the node reports a configuration error at execution time. If both are set, the Issuer takes precedence (discovery is used).

**Conditional (grant-type-aware): OIDC Client Secret, Resource Owner Username, and Resource Owner Password are all optional at the credential level so a single credential can support both grant types. Which fields are actually required is enforced at execution time based on the node's Grant Type selection:

Grant Type	Required credential fields	Optional fields
Client Credentials	Client ID, Client Secret	Username, Password (ignored)
Password	Client ID, Username, Password	Client Secret (sent if present)

The credential field descriptions (tooltips in the n8n UI) document which grant type each field applies to, so you can decide what to fill in based on the flow you intend to use.

Endpoint Discovery

Option A — OIDC Issuer (recommended)

Provide the Issuer base URL (e.g. https://login.example.com/realms/myrealm). The node fetches:

GET <issuer>/.well-known/openid-configuration

and reads token_endpoint and jwks_uri from the discovery document. This is the recommended approach because it keeps endpoint configuration in sync with the IdP.

Option B — OIDC Token Endpoint (direct)

If you cannot use discovery (e.g. a non-standard IdP or a restricted network), leave the Issuer blank and provide the token endpoint URL directly:

https://login.example.com/realms/myrealm/protocol/openid-connect/token

In this mode you must also supply OIDC JWKS URI yourself if you want to use the Verify processing mode.

Client Authentication

When a Client Secret is configured, the node authenticates to the token endpoint using HTTP Basic Auth per RFC 6749 §2.3.1:

Authorization: Basic base64(form_encode(client_id):form_encode(client_secret))

For public clients (no secret — only valid on the Password grant), the secret is omitted and the client_id is sent in the form body instead:

grant_type=password&username=...&password=...&client_id=...

Each Basic component is independently UTF-8 form-encoded, with spaces encoded as +, before adding the colon separator and applying Base64. Configure the original client ID and secret, not pre-encoded strings. They are never duplicated in the form body when Basic authentication is used.

The appropriate behaviour is chosen automatically based on whether OIDC Client Secret is filled in. Setup failures cause no token POSTs; with Continue On Fail, each input receives a paired error. See batch processing.

Example: Keycloak

Field	Value
OIDC Issuer	https://login.example.com/realms/myrealm
OIDC JWKS URI	(left blank — auto-discovered)
OIDC Client ID	my-m2m-client
OIDC Client Secret	••••••••••••

Example: Direct endpoint (no discovery)

Field	Value
OIDC Issuer	(blank)
OIDC Token Endpoint	https://login.example.com/realms/myrealm/protocol/openid-connect/token
OIDC JWKS URI	https://login.example.com/realms/myrealm/protocol/openid-connect/certs
OIDC Client ID	my-m2m-client
OIDC Client Secret	••••••••••••

Local Development

For local development, any OIDC-compliant IdP can be used. A quick way to test is to run Keycloak in Docker:

docker run -p 8080:8080 -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN=admin quay.io/keycloak/keycloak:latest start-dev

Then configure the credential against http://localhost:8080/realms/test and create a confidential client with client_credentials (and optionally password) in the client's Capability config.