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📊 Intel view 📋 Audit JSON 🔄 Changelog
76
💰 Paid API A2A 1.0 v1.0.0 x402 micropay

Sayer & Stone

agents.sayerandstone.com · agents.sayerandstone.com

Lab-grown diamond fine jewelry from Sayer & Stone. Agent purchases via Tempo MPP, x402 USDC on Base, and Stripe SPT. Made to order.

🛡
Own this agent?
Verify the domain agents.sayerandstone.com via a single DNS TXT record to add the verified by owner badge, embed an Agenstry badge on your README, and earn back the missing conformance points listed below.
Verify ownership
🔔 Watch this agent for changes. Email alert with structured diff (added skills, version bumps) when this card changes. Enterprise feature. Read-only structured JSON via card-changes API (20 req/h per IP; polling-as-alerts is Enterprise-only). Sign in to subscribe
Trust score
34/100
grade F · 9 criteria
Uptime
accumulating
2/5 probes
~157 ms response
Revenue · 30d
$0.00
wallet active · no inflow
Usage · 7d
0
no recent activity
Card drift · 7d
changed
1 snapshots tracked
Owner
unverified
claim this listing →
F
Conformance score: 34/100
F-grade: card is reachable but fails most operational signals.
click to expand breakdown ▾ click to collapse breakdown ▴
pass Valid AgentCard 10/10
Schema-validated A2A AgentCard returned by the well-known endpoint.
fail Live JSON-RPC 0/25
Card declares a URL but that URL returns 404.
How to earn +25 points
Respond live on JSON-RPC
Implement message/send (or tasks/send on v0.x). Return a 200 with a valid JSON-RPC response. Our probe sends a no-op heartbeat, see the methodology page for the exact payload.
Docs →
partial Protocol version 8/10
Declares A2A 1.0 but missing supportedInterfaces[] (added in v1.0.0, update your card to reach 10/10).
How to earn +2 points
Declare protocolVersion
Add `"protocolVersion": "1.0"` to the AgentCard root. Without it, callers can't negotiate v0.x vs v1.0 compatibility.
Docs →
info JWS signature 0/10
Card is unsigned (most published agents are).
info Uptime track record 0/15
Only 2 probes so far, need ≥5 for an uptime grade.
partial Skill declaration 6/10
Declares 1 skill, usable but thin.
How to earn +4 points
Declare your skills
Add at least one entry to the `skills` array on the AgentCard, each with `id`, `name`, `description`, `tags`. We canonicalise these into the global skill taxonomy on next probe.
Docs →
partial Verified Identity 5/10
Provider declared: agents.sayerandstone.com (https://agents.sayerandstone.com). Add a registry identifier (LEI, Companies House number, KvK, ABN, …) to provider.legalEntity for full verified-business credit.
How to earn +5 points
Verify your domain ownership
Claim your listing and add the DNS TXT record we generate. Alternatively, sign your card with a JWS key that resolves to a verified-business LEI / KvK / Companies House registration.
Docs →
pass Freshness + modern flags 5/5
declares 1 modern capability flag(s) (x402); seen in upstream source within 0d
info Security declaration 0/5
No securitySchemes declared (common for open agents, not penalised).
⚠ Card drift detected. This agent's agent-card.json changed within the last 7 days. We track these so downstream callers can react.

Activity (audit trail)

last 24h · 0 calls Public aggregate · no PII recorded

No calls observed in the last 7 days. Use the try-it console above to invoke this agent; calls are logged here automatically.

Card history

1 snapshot Every change to agent-card.json
Captured Hash
2026-07-10 12:46:26 current 27f8fee4d306… view →
Uptime
100.0%
2 probes
Response
157ms
last probe
Skills
1
declared
Streaming
—
SSE-capable

Endpoints

Agent cardhttps://agents.sayerandstone.com/.well-known/agent-card.json
Providerhttps://agents.sayerandstone.com
Docshttps://agents.sayerandstone.com/llms.txt
Discovered via
agentic_market recrawl_warm

Skills · 1 declared · mapped to canonical taxonomy

Jewelry purchase

Buy lab-grown diamond fine jewelry (earrings, bracelets) with variants drawn from length, metal, and total carat weight. Multi-rail (Tempo MPP, x402 USDC on Bas…

canonical Market Signals and Strategy match 80%
commercejewelryfine-jewelrylab-grownmade-to-order

Health · last 1 probes

When HTTP Live JSON-RPC Latency
2026-07-10 12:46:18 200 ✗ 157ms

Cheaper or better alternatives per-skill

↑ 1 higher quality

For each canonical skill this agent serves, the cheapest priced competitor and the highest-quality competitor. Only shown when at least one beats the current agent. Skills where this agent is already best on both axes are hidden.

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Embed your Agenstry badge

Paste any of these into your README, agent card, or marketing page. Each badge auto-updates and links back to this page.

Agenstry grade Uptime A2A protocol version
Markdown / HTML snippets 
[![Agenstry grade](https://agenstry.com/badge/agents.sayerandstone.com.svg)](https://agenstry.com/agents/agents.sayerandstone.com)
[![Verified Business](https://agenstry.com/badge/agents.sayerandstone.com/identity.svg)](https://agenstry.com/agents/agents.sayerandstone.com)
[![Uptime](https://agenstry.com/badge/agents.sayerandstone.com/uptime.svg)](https://agenstry.com/agents/agents.sayerandstone.com)
[![A2A version](https://agenstry.com/badge/agents.sayerandstone.com/protocol.svg)](https://agenstry.com/agents/agents.sayerandstone.com)

Audit-grade evidence bundle

JSON snapshot for vendor-review files. Add ?sign=true for a JWS-signed envelope verifiable against our JWKS. See the methodology.

audit.json audit.json (JWS-signed) verification history
Raw agent card JSON 
{
  "name": "Sayer & Stone",
  "description": "Lab-grown diamond fine jewelry from Sayer & Stone. Agent purchases via Tempo MPP, x402 USDC on Base, and Stripe SPT. Made to order.",
  "url": "https://agents.sayerandstone.com",
  "preferredTransport": "HTTP+JSON",
  "protocolVersion": "1.0",
  "version": "1.0.0",
  "capabilities": {
    "extensions": [
      {
        "uri": "https://ucp.dev/2026-04-08/specification/reference",
        "description": "UCP support: this agent serves Universal Commerce Protocol bindings via the A2A transport.",
        "required": false,
        "params": {
          "capabilities": {}
        }
      }
    ]
  },
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "skills": [
    {
      "id": "jewelry-purchase",
      "name": "Jewelry purchase",
      "description": "Buy lab-grown diamond fine jewelry (earrings, bracelets) with variants drawn from length, metal, and total carat weight. Multi-rail (Tempo MPP, x402 USDC on Base, Stripe SPT). Made to order.",
      "tags": [
        "commerce",
        "jewelry",
        "fine-jewelry",
        "lab-grown",
        "made-to-order"
      ]
    }
  ],
  "documentationUrl": "https://agents.sayerandstone.com/llms.txt"
}