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Authentication

Multistore has two distinct authentication concerns:

  1. Client authentication — How clients prove their identity to the proxy
  2. Backend authentication — How the proxy authenticates with backend object stores

Client Authentication

Clients authenticate with the proxy using one of three methods:

MethodUse CaseHow It Works
AnonymousPublic datasetsNo credentials needed for GET/HEAD/LIST
Long-lived access keysService accounts, internal toolsStatic AccessKeyId/SecretAccessKey with SigV4 signing
OIDC/STS temporary credentialsCI/CD, user sessions, federated identityExchange a JWT from an OIDC provider for scoped temporary credentials

The proxy verifies all signed requests using standard AWS Signature Version 4 (SigV4). Any S3-compatible client works without modification — just set the endpoint URL.

The OIDC/STS flow is the recommended approach for most use cases. See Client Auth Setup for configuration details.

Backend Authentication

The proxy authenticates with backend object stores using one of two methods:

MethodUse CaseHow It Works
Static credentialsSimple setupsaccess_key_id/secret_access_key stored in the proxy config
OIDC backend authProduction, credential-freeProxy acts as its own OIDC provider, exchanges self-signed JWTs for cloud credentials

OIDC backend auth eliminates the need to store long-lived backend credentials. See Backend Auth for details.