---
title: "Evidence purchase with explicit mode and current eligibility checks"
method: GET
path: "/api/v1/changes"
---

# Evidence purchase with explicit mode and current eligibility checks

`GET /api/v1/changes`

## Request

- Base URL: `https://alpnai.com`
- URL: `https://alpnai.com/api/v1/changes`
- Auth: HTTP bearer

Read /api/v1/offers/changes first for public price, access and availability metadata. Authentication errors include this URL as offer_url and in Link rel=describedby. Only an eligible authenticated live request can receive a payable x402 challenge.

## Query parameters

- `since` string, date

## Headers

- `X-ALPNAI-Mode` 'sandbox' | 'live', required
- `Idempotency-Key` string, required
- `X-AlpNAI-Mandate` string
- `PAYMENT-SIGNATURE` string

## Response `200`

Sandbox receipt, or a finalized live receipt with its result. Inspect settled and network.

## Other responses

- `202`: Payment confirmation pending. Poll the same order; do not send a second payment.
- `400`: Invalid input
- `401`: Unauthorized agent
- `402`: Exact x402 payment challenge with frozen price, terms and expiry. No paid result delivered.
- `403`: Budget exhausted
- `409`: Idempotency conflict
- `503`: Commerce unavailable or billing qualification required; no payment requested.

---

[API](https://skmtc.dev/alpnai/apis/alpnai-agent-api.md) · [All operations](https://skmtc.dev/alpnai/apis/alpnai-agent-api/llms.txt) · [OpenAPI document](https://skmtc.dev/alpnai/apis/alpnai-agent-api/revisions/ab20b858b8d4?raw)