# Witnessory Post-Quantum TLS/SSH Domain Check

> Witnessory Post-Quantum TLS/SSH Domain Check is a paid API for AI agents from api.witnessory.org, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Returns a cryptographically signed attestation of whether a specific domain supports post-quantum key exchange in TLS and SSH

## Facts

- Endpoint: GET https://api.witnessory.org/pay/check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/witnessory-post-quantum-tls-ssh-domain-check-f26e3833
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yMD-wxrUAiqJyPPiJmSuy

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 witnessory-post-quantum-tls-ssh-domain-check-f26e3833
```

Example prompt: Check whether cloudflare.com supports post-quantum key exchange — I want a signed, verifiable attestation of its post-quantum TLS readiness level.

## When to prefer this

Choose this endpoint when you need a cryptographically signed, independently verifiable attestation of a domain's post-quantum TLS or SSH status — not just a raw TLS handshake inspection. It is ideal for compliance evidence, vendor audits, or any workflow requiring tamper-evident proof signed with both classical (ed25519) and post-quantum (MLDSA65) algorithms. Prefer it over generic TLS scanners when auditability and signature provenance matter.

## Known failure modes

- Domain does not support post-quantum key exchange — returns a lower readiness level rather than error
- Network unreachable or domain does not exist — may return an error or failed probe status
- Payment not provided or insufficient — HTTP 402 response before any domain check is performed
- Rate limiting or probe unavailability — transient failures across probe nodes

## How this service works

58.4% of the top 10,000 sites negotiate post-quantum TLS; 52.3% of SSH servers offer post-quantum key exchange. As of 2026-10-27, from 4 probes; signed readings, recomputable.

## Output

A JSON object containing: a 'record' with the domain, readiness level (e.g. 'ready'), and UTC timestamp of the check; a human-readable 'summary' describing the negotiated post-quantum algorithm (e.g. X25519MLKEM768 with TLS 1.3); and 'signatures' with both ed25519 and MLDSA65 cryptographic signatures over the result, making the attestation independently verifiable and recomputable.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "record": {
   "level": "ready",
   "domain": "example.org",
   "checked_utc": "2026-10-21T10:00:00Z"
  },
  "summary": "example.org: a current browser gets post-quantum key exchange (X25519MLKEM768, TLS 1.3)",
  "signatures": {
   "ed25519": "...",
   "mldsa65": "..."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/witnessory-post-quantum-tls-ssh-domain-check-f26e3833/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.witnessory.org](https://www.zero.xyz/host/api.witnessory.org/llms.txt)