@ausca/sdk

The typed engine behind the ausca front door: catalog-bound invocations of Ausca metered agent infrastructure services, paid per call under a hard USD cap, with receipt-backed results.

Most consumers want the ausca package, which re-exports this entire surface and adds the CLI and local MCP server. Depend on @ausca/sdk directly when you only need the library.

Client

import { AuscaClient } from "@ausca/sdk";

const client = AuscaClient.withLocalKey({
  privateKey: process.env.AUSCA_PRIVATE_KEY,
  maxPaymentUsd: 0.5,
});

const offer = await client.offer("document.ocr");
const price = await client.price("document.ocr");
const outcome = await client.invoke("document.ocr", { artifact });
const state = await client.invocation("inv_...");

The envelope carries the offer's immutable revision and schema digests exactly as the catalog declares. Each invoke starts with a fresh idempotency key. For recovery after an uncertain response, retry with the same caller-owned idempotencyKey; use a new key for a new intentional purchase, even when the input is identical.

Payment authorities

The client pays through a PaymentAuthority, a small port any rail can implement: wrap a fetch so 402 challenges are paid within policy, and decode settlement evidence from the response. Built in:

• localKeyAuthority({ privateKey, maxPaymentUsd, network? }): x402 v2 with a local signing key via the official @x402/* libraries.
• x402Authority(config): the official x402 client configuration passed through verbatim, so any registered scheme client works.
• inertAuthority(): pays nothing; reads and price discovery.

Caps are enforced inside the authority before anything is signed.

Artifact store

Artifact-backed offers take an immutable input commitment. client.commit(bytes, mediaType) uses Ausca's keyless temporary ingress and creates a fresh temporary commitment on every call. Pass { idempotencyKey: "..." } only to recover the same uncertain upload. The client verifies the returned digest-backed evidence and returns the commitment the invocation input carries. No account or API token is needed. ArtifactStore remains the narrow port for a custom storage policy.

Successful paid state includes receipt_ref.public_url, an immutable hash-only proof of the Ausca service, public price, completion time, and receipt digest. It contains no request or result bytes, content digests, or access capabilities. Anyone holding the unguessable URL can read it.

A result larger than the offer's inline bound arrives as output_artifact instead of output. client.artifactAccess(artifactRef) mints a 60-second download URL for it; verify the bytes against contentDigest. A failed invocation carries failure.code and failure.message.

Testkit

@ausca/sdk/testkit ships an in-process x402 v2 resource and an Ausca-shaped service fixture (catalog, schema, payable route, invocation read) for offline test suites. No chain is involved.

License

MIT