# KHOTEM Seal — Content Notarization & Audit

> KHOTEM Seal — Content Notarization & Audit is a paid API for AI agents from khotem.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Cryptographically seals and notarizes content or a pre-computed SHA-256 hash, creating a verifiable timestamped record for audit purposes, paid instantly via USDC on Base.

## Facts

- Endpoint: POST https://khotem.com/api/seal
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/khotem-seal-content-notarization-audit-d5f2163b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JbXB3NrnbQESDDOaB7Ebi

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 khotem-seal-content-notarization-audit-d5f2163b -d '<json body>'
```

Example prompt: Seal and notarize this contract text for me so I have a tamper-proof timestamped record — the content is: 'Agreement between Acme Corp and Jane Doe dated 2025-06-01, terms: $10,000 for 3 months of services.' Pay the 5 cent fee automatically.

## When to prefer this

Choose this endpoint when you need a lightweight, no-signup, pay-per-use cryptographic notarization of content or a hash — particularly when KYC-free instant payment via USDC on Base is desirable and you want a per-call audit record without a subscription or account setup.

## Known failure modes

- Missing both 'hash' and 'content' fields — endpoint requires at least one
- Invalid SHA-256 hash format — must be a valid 64-character hex string
- Payment failure — insufficient USDC balance or Base network issues
- Network timeout during seal creation
- Duplicate seal submission may create a new record rather than returning the existing one

## How this service works

Paid cryptographic witness services for autonomous agents and humans: seals, attestations, verification, audit, sealed document thread. x402-native micropayments, USDC on Base / Polygon / Solana, direct on-chain verification. No accounts, no API keys, no KYC.

## Output

A seal certificate or notarization record containing the timestamped cryptographic proof of the content or hash, suitable for audit trails and verifying that content existed and was unchanged at the time of sealing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hash": {
   "type": "string",
   "description": "Pre-computed sha256 hex (64 chars)"
  },
  "content": {
   "type": "string",
   "description": "Content to hash and seal"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "note": "content not stored: hashed and forgotten",
 "proof": "recorded in the KHOTEM ledger; verifiable via /api/attest",
 "sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
 "witness": "KHOTEM-SEAL",
 "timestamp": "2026-08-24T12:00:00.000Z",
 "seal_stamp": "a1b2c3d4e5f60708",
 "payment_seal": "1020304050607080"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/khotem-seal-content-notarization-audit-d5f2163b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from khotem.com](https://www.zero.xyz/host/khotem.com/llms.txt)