---
name: ausca
description: Discover and invoke Ausca metered infrastructure services through canonical SKILL.md, HTTP, x402 v2, and MCP surfaces with immutable offer bindings and receipt-backed results.
---

# Ausca

Ausca provides agent infrastructure on demand: metered services an agent can discover, pay for, invoke, and verify without an account or provider API keys. Start with the service instructions, preserve the catalog bindings exactly, and treat a terminal receipt as the proof of work.

## Connect

- Service catalog: `https://ausca.com/catalog.json`
- OpenAPI discovery: `https://ausca.com/openapi.json`
- Canonical OpenAPI: `https://ausca.com/openapi.yaml`
- MCP manifest: `https://ausca.com/mcp.json`
- MCP transport: `https://ausca.com/mcp`
- npm package: `ausca` (typed client, CLI, local MCP server via `npx ausca mcp`)
- Python package: `ausca` (typed client and CLI)
- Documentation: `https://ausca.com/docs`

## Choose a service

- [Browser Session](https://ausca.com/skills/browser-session/SKILL.md) (`browser.session`, `POST /v1/lease-browser`): Lease one remote browser with standard CDP access for 10, 30, or 60 minutes.
- [Document Analysis](https://ausca.com/skills/document-analysis/SKILL.md) (`document.analysis`, `POST /v1/analyze-document`): Extract normalized forms, tables, signatures, or layout from a document.
- [Document OCR](https://ausca.com/skills/document-ocr/SKILL.md) (`document.ocr`, `POST /v1/extract-text`): Extract normalized text from a scanned document.
- [Agent Inbox](https://ausca.com/skills/agent-inbox/SKILL.md):
  - `inbox.receive`, `POST /v1/open-inbox`: Start one renewable random receive-only email address with 1 hour, 24 hours, or 7 days prepaid.
  - `inbox.extend`, `POST /v1/extend-inbox`: Add 1 hour, 24 hours, or 7 days to one active receive-only inbox without changing its address.
- [Media Transcription](https://ausca.com/skills/media-transcription/SKILL.md) (`media.transcription`, `POST /v1/transcribe-media`): Transcribe an immutable audio or video artifact into normalized text.

The linked service SKILL.md owns the human workflow. `catalog.json`, its linked schemas, and canonical `openapi.yaml` own the exact application contract; `openapi.json` adds the derived x402 discovery view.

## Artifact inputs

Document and media services take an immutable commitment instead of raw bytes. If one is not already available, use `ausca commit <file>`, the typed client, or keyless `POST https://ausca.com/v1/artifacts`. Send canonical standard-base64 bytes, their SHA-256 digest, the truthful media type, and a stable idempotency key. Verify every returned commitment field against the local bytes. Ingress is free and creates no paid invocation; retry an uncertain response or HTTP 429 with the same body and key. Follow the selected offer's current catalog size limit and retrieve needed input or output artifacts within their 24-hour retention window.

## Paid invocation

1. Resolve the active offer and copy its immutable revision, schema digests, and canonicalizer into one invocation envelope.
2. For artifact-backed work, supply the verified immutable commitment; do not place document, audio, or video bytes in invocation JSON.
3. Send the exact envelope to the offer's own payable resource, the `route` in `catalog.json` (for example `POST https://ausca.com/v1/extract-text`), without payment material to receive the live payment requirement. For x402 v2, decode the `PAYMENT-REQUIRED` header.
4. After explicit authorization, retry the same bytes and idempotency key using the selected payment rail. For x402 v2, use `PAYMENT-SIGNATURE`; read `PAYMENT-RESPONSE` on settlement.
5. Read `GET /v1/invocations/{invocation_id}` until terminal state when completion is asynchronous or a connection ends.

The unsigned probe creates no purchase. Never mint a second idempotency key because a connection ended, and never treat a payment response alone as provider completion.

## MCP boundary

The public Streamable HTTP MCP server exposes the enabled discovery, preparation, invocation-state, cancellation, and resource lifecycle tools described by `mcp.json`. The local `npx ausca mcp` client also exposes keyless artifact commit and can pay within an operator-set cap. Neither MCP surface accepts wallet secrets as model-authored arguments. Paid execution remains on the canonical HTTP invocation resource, while browser and inbox lifecycle tools read lease authority from the MCP HTTP `Authorization` header.

## Evidence

Validate output against the offer's published schema. Preserve the offer revision digest, input and output schema digests, invocation identity, output commitment, and terminal receipt reference with any result that will be stored or acted on. Successful paid calls include `receipt_ref.public_url`: an immutable, unguessable hash-only proof disclosing the receipt digest, Ausca service, public price, and completion time, but no request or result bytes, content digests, access capabilities, payment credentials, or provider evidence. Anyone holding the URL can read it, so share it deliberately.