API Reference

The XChain Platform exposes three public HTTP APIs. Together they cover the full read/write lifecycle: read chain state from the explorer, build and broadcast transactions with the encoder, and discover configuration or fee quotes from the hub.

Service	Protocol	Use it to	Reference
Explorer	REST (read-only)	Query tokens, balances, actions, markets, dispensers, contracts, prices, and more	Explorer API, WebSocket API
Encoder	JSON-RPC 2.0	Build unsigned PSBTs that embed ACTION payloads, then broadcast the signed result	Encoder API
Hub	JSON-RPC 2.0	Service discovery, fee quotes, price snapshots, validator and cross-chain coordination	Hub API

Most application developers only need the explorer (to read state) and the encoder (to build transactions). The high-level xchain-sdk wraps both of these with typed helpers, so reach for the raw APIs when you need a surface the SDK does not cover or you are working outside JavaScript.

Base URLs and networks

The public services are reachable at:

Service	Public base URL
Explorer	`https://explorer.xchain.io/{COIN}/api/`
Encoder	`https://encoder.xchain.io/{COIN}/`
Hub	`https://hub.xchain.io/{COIN}/`

Every request is scoped to a chain and network by a {COIN} prefix in the path:

Network	Prefix	Network	Prefix	Network	Prefix
Bitcoin mainnet	`BTC`	Litecoin mainnet	`LTC`	Dogecoin mainnet	`DOGE`
Bitcoin testnet	`TBTC`	Litecoin testnet	`TLTC`	Dogecoin testnet	`TDOGE`
Bitcoin regtest	`RBTC`	Litecoin regtest	`RLTC`	Dogecoin regtest	`RDOGE`

Self-hosted instances bind a single network and are reached directly at http://{host}:{port}/. The regtest prefixes apply to local development stacks (see Regtest Development).

Machine-readable specs

Each service serves its own spec, suitable for code generation, client tooling, or loading into an LLM:

Service	Spec format	Endpoint
Explorer	OpenAPI 3.1	`GET https://explorer.xchain.io/openapi.json`
Encoder	OpenRPC 1.3.2	`GET https://encoder.xchain.io/{COIN}/openrpc.json`
Hub	OpenRPC 1.3.2	`GET https://hub.xchain.io/{COIN}/openrpc.json`

Load the OpenAPI document into Swagger UI, Redoc, or an OpenAPI client generator; load the OpenRPC documents into an OpenRPC playground or generator. An LLM-friendly digest of the full docs is published at https://docs.xchain.io/llms.txt.

Calling the APIs

The explorer is a plain REST service. URLs follow GET /{COIN}/api/{method}/{query}/{type} and return JSON:

# Token metadata on Bitcoin mainnet
curl https://explorer.xchain.io/BTC/api/token/MYTOKEN

# Balances for an address
curl https://explorer.xchain.io/BTC/api/balances/bc1qexampleaddress

The encoder and hub are JSON-RPC 2.0 services. Send an HTTP POST to the service root with the standard envelope:

curl -X POST https://encoder.xchain.io/BTC/ \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"estimate_fee","id":1}'

Authentication and limits

Service	Auth	Rate limit
Explorer	None; all endpoints are read-only	`429` after 500 requests per 60s window
Encoder	Optional `x-api-key` (public instances run open)	Per-instance, configurable
Hub	`x-api-key` required for write and admin methods; read methods are open	Per-instance, configurable

JSON-RPC errors follow the 2.0 convention with a numeric code: -32602 invalid params, -32603 internal error, -32001 unauthorized, -32029 rate limited. The full registry is documented at Error Codes.

API Reference

Base URLs and networks

Machine-readable specs

Calling the APIs

Authentication and limits

See also