# Sellat Qualified Timestamp – Issue eIDAS Proof

> Sellat Qualified Timestamp – Issue eIDAS Proof is a paid API for AI agents from sellat.app, paid per call via x402, $0.9/call, status unknown (last checked 2026-10-20).

Issues an EU eIDAS-qualified RFC 3161 electronic timestamp (.tsr) on a Sellat proof, legally demonstrating a file's existence at a specific point in time across the EU.

## Facts

- Endpoint: POST https://sellat.app/api/v2/proofs/%7Bid%7D/qualified?utm_source=zero.xyz
- Price: $0.9/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sellat-qualified-timestamp-issue-eidas-proof-1428abd3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LlpKvcKW6dN08GKPsBjLo

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 sellat-qualified-timestamp-issue-eidas-proof-1428abd3 -d '<json body>'
```

Example prompt: I need an EU eIDAS-qualified timestamp for my Sellat proof — can you issue a qualified RFC 3161 .tsr certificate for proof ID abc123 so I have legal proof of when this file existed?

## When to prefer this

Choose this endpoint when you need a legally recognized, EU eIDAS-qualified electronic timestamp — not just a blockchain hash. It's the right choice for regulatory compliance, legal proceedings, IP protection, or any scenario requiring a timestamp with legal presumption across EU member states. Prefer it over plain blockchain timestamping when eIDAS legal weight or RFC 3161 standard compatibility is required.

## Known failure modes

- Invalid or non-existent proof_id returns an error
- Payment of 0.9 USDC not processed or wallet insufficient funds causes failure
- Qualified TSP (Trust Service Provider) temporarily unavailable
- Proof already has a qualified timestamp issued (duplicate request)
- Malformed request body causes 400 error

## How this service works

Prueba de existencia para tus archivos: demuestra que ya existían, con sello de tiempo cualificado y presunción legal en toda la UE.

## Output

Returns a JSON object confirming the qualified timestamp was issued, including: the RFC 3161 UTC time, a URL to download the .tsr file, the issuing EU qualified trust service authority name, the policy OID (0.4.0.2023.1.1), the serial number, and the on-chain payment transaction hash on Base. The .tsr can be verified with any RFC 3161 tool (e.g. openssl ts -verify).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "verify": "openssl ts -verify -in <file>.tsr -data <file> (any RFC 3161 tool); the .tsr is downloaded with the wallet’s key",
  "created": true,
  "payment": {
   "charged": true,
   "amount_usd": "0.9",
   "transaction": "<tx hash on Base>"
  },
  "proof_id": "<proof_id>",
  "qualified": {
   "time": "<RFC 3161 time, UTC>",
   "state": "issued",
   "tsr_url": "https://sellat.app/api/v2/proofs/<id>/qualified.tsr",
   "authority": "<EU qualified trust service provider>",
   "policy_oid": "0.4.0.2023.1.1",
   "serial_number": "<token serial>"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sellat-qualified-timestamp-issue-eidas-proof-1428abd3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sellat.app](https://www.zero.xyz/host/sellat.app/llms.txt)