2. Radix APIs

API Overview

Radix exposes four APIs at different abstraction levels. Most developers only need the Gateway API.

Gateway API

The Gateway API is the primary interface for dApp developers. It provides entity state queries, transaction submission, stream queries, and historical state access — all via JSON POST requests with cursor-based pagination.

Official Endpoints

These are rate-limited by IP. For production dApps, use a third-party provider or run your own Gateway.

Key Endpoint Groups

• /state/* — entity details, resource balances, metadata, vault contents
• /transaction/* — submit, preview, and check transaction status
• /stream/transactions — query committed transactions with filters
• /status/gateway-status — current ledger state version and epoch

Use the Gateway SDK (@radixdlt/babylon-gateway-api-sdk) for typed TypeScript access.

Core API

The Core API gives direct access to a node's view of the ledger — transaction-level detail, raw state, and streaming committed transactions. It includes an LTS (Long-Term Support) sub-API designed for exchange integrators.

LTS Endpoints

• /lts/transaction/submit — submit a notarized transaction
• /lts/transaction/status — check transaction status by intent hash
• /lts/state/account-all-fungible-resource-balances — all token balances for an account
• /lts/transaction/construction — get current epoch for building transactions

The Core API requires running your own node. Third-party providers include Grove (free tier: 5M requests/day) and NowNodes.

Engine State and System APIs

Engine State API

Provides complete current state at the Radix Engine abstraction level. More comprehensive than Core API state queries but requires explicit node configuration (available since node v1.1.3.1). Useful for advanced state inspection without running a full Gateway.

System API

Node diagnostics only — health checks, connection info, performance metrics. Used for monitoring, not application development.

Which API Should I Use?

External Links

• Gateway API reference
• Core API reference
• Gateway API providers
• Core API providers
• API comparison (Learn Radix)