@rpp402/sdk

Published under MIT to the @rpp402 scope on npm.

npm install @rpp402/sdk

TypeScript SDK for RPP402. It mirrors the protocol exactly - one method per primitive, no incidental abstractions - and validates every response against @rpp402/protocol's JSON Schemas at runtime, not just at compile time. Ships ESM and CommonJS builds with full type declarations. Requires Node.js 20 or newer (it uses the global fetch).

Quickstart

import { createClient } from "@rpp402/sdk";

const rpp = createClient({ agentWallet: "0xYourAgentWalletAddress" });

const service = await rpp.discover("market-data.example");      // RPP402-001
const session = await rpp.session.create(service);              // RPP402-003

const quote = await session.quote(service, {                    // RPP402-002 (+ attaches leg)
  capability: "market-data.quote",
  params: { ticker: "NVDA" },
  settlementAsset: service.supported_assets[0],
});

await session.intent({                                          // RPP402-004
  asset: quote.price.asset,
  authorization: { type: "agentic_account_delegation", account_id: "aa_...", delegation_ref: "del_..." },
});

await session.settle();                                         // RPP402-005 (polls to a terminal state)
const receipt = await session.receipt();                        // RPP402-006

For an eip712_signature authorization instead of Agentic Account delegation, pass a signTypedData function to createClient() and omit authorization from session.intent() - the SDK builds and signs the payload itself.

What you get

• One method per primitive. discover, session.create, session.quote, session.intent, session.settle, session.receipt - each maps to exactly one RFC.
• Validated responses. A non-conformant server produces an Rpp402ValidationError instead of a malformed object being passed through silently.
• Typed errors. Every non-2xx response becomes an Rpp402Error carrying the RFC 9457 problem+json type, status, and detail. Network failures, timeouts, and malformed bodies are normalized to the same error type, so you never have to catch a raw fetch rejection.
• Exact money. Leg totals are summed with BigInt decimal-string math, never parseFloat - amounts don't drift.
• Built-in timeout. Requests time out after 30s by default; pass timeoutMs (or your own AbortSignal) to change it.
• No bundled wallet library. signTypedData is caller-injected, so you choose viem, ethers, or an Agentic Account SDK.

MPP interop

Client-side helpers for MPP (the Machine Payments Protocol) live under the mpp namespace, so an agent can also pay MPP-protected resources:

import { mpp } from "@rpp402/sdk";

const res = await fetch(url); // 402 with `WWW-Authenticate: Payment ...`
const challenges = mpp.parseChallenges(res.headers.get("www-authenticate") ?? "");
const authorization = mpp.buildAuthorization(signedCredential); // "Payment <base64url>"
await fetch(url, { headers: { authorization } });

MPP is an HTTP auth scheme with no third-party facilitator - settlement runs on its own rails (Stripe on Tempo). These helpers cover reading challenges and building the credential header; the method-specific credential is caller-supplied, the same way signTypedData is.

Learn more

• Protocol RFCs: https://rpp402.com/docs
• Schemas and types: @rpp402/protocol
• CLI and scaffolding: @rpp402/cli