API Reference

DeltaFi exposes two APIs: a REST API for data operations, system management, and streaming, and a GraphQL API for querying and mutating system state.

Base URLs

API	Base URL	Notes
REST	/api/v2/	All REST endpoints except plugin registration
Plugin Registration	/plugins	Used by plugins during startup
GraphQL	/api/v2/graphql	Single endpoint, POST only
GraphiQL IDE	/graphiql	Interactive query editor (browser)

In local development, use http://deltafi.localhost as the host. In production, use the configured DeltaFi domain over HTTPS.

Authentication

All API requests require authentication unless the system is running in disabled auth mode. See Authentication for details on auth modes, headers, and the permissions model.

For most programmatic access, requests pass through an auth gateway that sets identity headers. Direct API calls should use Basic authentication or certificate-based authentication depending on the configured mode.

Common Error Responses

REST Errors

REST endpoints return standard HTTP status codes:

Status	Meaning
200	Success
204	Success, no content
400	Bad request (invalid input, validation failure)
403	Forbidden (missing required permission)
404	Resource not found
413	Payload too large (insufficient storage for ingress)
422	Unprocessable entity (semantic validation error)
429	Rate limited
500	Internal server error
501	Not implemented (feature disabled)
503	Service unavailable

Error responses use this format:

{
  "error": "Description of what went wrong"
}

GraphQL Errors

GraphQL requests always return HTTP 200. Errors appear in the errors array:

{
  "data": null,
  "errors": [
    {
      "message": "Description of the error",
      "locations": [{"line": 1, "column": 1}],
      "path": ["mutationName"],
      "extensions": {
        "classification": "DataFetchingException"
      }
    }
  ]
}

Many mutations return a Result type with structured success/error information:

type Result {
  success: Boolean!
  info: [String]
  errors: [String]
}

API Sections

REST API

• DeltaFiles — Ingress, export, import, annotations, content retrieval
• Events — System event notifications
• Users and Roles — User, role, and permission management
• Metrics — System, flow, action, and queue metrics
• System — Status, versions, configuration, snapshots, SSE
• Plugins — Plugin registration and scaffold generation
• Federation — Fleet leader operations and federated search
• Artifact Registry — Versioned artifact publishing, download, aliases, and purge

GraphQL API

• GraphQL Overview — Endpoint usage, custom scalars, conventions
• DeltaFiles — Query, filter, resume, replay, acknowledge DeltaFiles
• Flows — Flow plans, state management, topics, test mode
• Plugins — Plugin queries, installation, variables
• Policies — Resume and delete policies
• System — Properties, snapshots, SSL, SpEL, links, lookup tables
• Testing — Integration test management