# witnessd Credits Purchase

> witnessd Credits Purchase is a paid API for AI agents from witnessd.vip, paid per call via x402, $1/call, status unknown (last checked 2026-10-12).

Purchase API credits for the witnessd neutral-witness service by paying $1 USDC, receiving an API key and credit balance in return.

## Facts

- Endpoint: POST https://witnessd.vip/api/credits?utm_source=zero.xyz
- Price: $1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/witnessd-credits-purchase-67071fcc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pOIn38oxRpJopafbrF8vr

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability witnessd-credits-purchase-67071fcc -d '<json body>'
```

Example prompt: I want to start using witnessd to independently archive and timestamp URLs — can you purchase $1 worth of credits so I get an API key to use?

## When to prefer this

Use this endpoint when you need to obtain a witnessd API key and fund your credit balance before making any witness/archive requests. This is the entry-point/onboarding endpoint — call it once before using any other witnessd capabilities. Prefer this over generic archiving services when you need Merkle-anchored, blockchain-timestamped, neutral third-party provenance on Base.

## Known failure modes

- Payment not received or insufficient USDC — returns payment error or 402
- Malformed request body (wrong bodyType or missing required fields) — returns 400 validation error
- Network or blockchain confirmation timeout — credits may not be issued immediately
- Duplicate payment attempts may not result in duplicate credits — idempotency not guaranteed

## How this service works

Pay a few cents to have any URL or API response independently fetched, hashed, timestamped and archived by a neutral third party. Merkle-anchored on Base. Built for AI agents; useful to humans.

## Output

Returns a JSON object containing a witnessd API key (prefixed 'wk_…') and a credit balance expressed in cents (e.g. credits_cents: 100), which can then be used to call witnessd's witnessing endpoints.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "api_key": "wk_…",
  "credits_cents": 100
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/witnessd-credits-purchase-67071fcc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from witnessd.vip](https://www.zero.xyz/host/witnessd.vip/llms.txt)