# Ysaere Agent Text Stamp

> Ysaere Agent Text Stamp is a paid API for AI agents from api.ysaere.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Returns a cryptographically signed hash receipt for a given text string, serving as a timestamped proof-of-existence for that exact text.

## Facts

- Endpoint: POST https://api.ysaere.com/v1/notary/stamp-text?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ysaere-agent-text-stamp-81aaf88c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UIdFfolnDjsuPFrWoOtLG

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 ysaere-agent-text-stamp-81aaf88c -d '<json body>'
```

Example prompt: Please stamp this text so I have a signed proof-of-existence for it: 'I, Jane Doe, agree to the terms outlined in this partnership proposal as of today.'

## When to prefer this

Use this endpoint when you need lightweight, per-call text notarization with no account setup, no text storage, and a flat $0.02 USDC cost. Prefer it over the sibling hash-only stamp endpoint when the input is raw text rather than a pre-computed hash. Ideal for agents that need tamper-evident audit trails for dynamic text without any persistent registration.

## Known failure modes

- Empty text input is rejected with an error before payment is taken
- Text exceeding 64 KB limit is refused
- Payment failure via x402 wallet results in no receipt being issued
- Malformed JSON input returns a validation error
- Network timeout before signing completes

## How this service works

Ysaere Agent Text Stamp — $0.02 USDC, no account needed. Input: {"text":"the exact text to stamp"}. Returns a signed hash of that text. The text is not stored. Empty text is refused. No payment was taken until the text is accepted. Wallet only. No account price.

## Output

A signed hash receipt containing a cryptographic hash of the submitted text and a timestamp signature, serving as verifiable proof-of-existence. The original text is not stored by the service. The receipt can be used to verify that the exact text existed at the time of stamping.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "Text to hash and stamp (up to 64 KB)"
  },
  "label": {
   "type": "string",
   "description": "Optional human-readable label (up to 160 chars)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ysaere-agent-text-stamp-81aaf88c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.ysaere.com](https://www.zero.xyz/host/api.ysaere.com/llms.txt)