SDK

Current state, honestly: the developer surface today is the node's RPC API plus the script engine. A higher-level SDK is in development and ships with the public testnet. This page answers the five questions it will cover — with today's answer for each.

How do I write a program?

A program is a script locking funds: you compose spending conditions from the opcode surface (signatures, timelocks, templates, Bitcoin-fact proofs), hash it, and send funds to the script hash. The SDK will provide covenant builders for the common patterns (vault, escrow, HTLC) so you don't hand-assemble script bytes.

How do I submit transactions?

Through the node: wallet RPCs for standard operations (wallet), raw-transaction RPCs for custom scripts. Standard Bitcoin-style flow: construct, sign, broadcast.

How do I verify Bitcoin?

You mostly don't have to — the chain does it. Your program states which Bitcoin fact it needs (TX_CONFIRMED on a payment, a difficulty read); the proof is a Merkle branch that any party can fetch from Bitcoin and submit. The SDK will automate proof construction from a Bitcoin transaction id.

How do I build a covenant?

Start from the patterns in Applications — each lists its primitives. The core trick is CTV: commit to the template of the spending transaction, and the covenant forces where funds go next. Recursion (a covenant that re-creates itself) comes from output introspection.

How do I talk to a Settlement Provider?

SPs expose a small HTTP API: fetch quotes, accept a swap, follow settlement. The reference SP implementation and its API documentation are published with the public testnet. → Settlement Providers