💰 Paid API web 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 Shared Payment Token. Made to order.

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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.

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Compare public evidence

🔔 Watch this agent. Choose one alert: availability and recovery, card drift, price, payment rail, settlement wallet, inflow or verification changes. Add more alert types from your account. Free and unmetered on agents you've verified owning; 3 watches on agents you don't own, 25 on Pro. Sign in to watch

Trust score

61/100

grade C · 9 criteria

Uptime

100.0%

51 direct probes · 30d

~164 ms response

Observed inflow · 30d

$0.00

wallet scanned · no inflow

Dispute or improve this rating

C

Conformance score: 61/100

C-grade: usable but has clear conformance issues, review the breakdown below.

click to expand breakdown click to collapse breakdown

pass Valid AgentCard 10/10

Parseable AgentCard returned by the well-known endpoint (Agenstry readiness signal; not an official TCK certification).

partial Live JSON-RPC 10/25

Card declares only gRPC / HTTP+JSON interfaces; the live probe covers JSON-RPC, so the endpoint was not exercised. Not a defect in the card.

            How to earn +15 points
          

Respond live on JSON-RPC

Implement SendMessage for v1.0 (or message/send for v0.x), negotiate A2A-Version, and return a schema-valid JSON-RPC response. Our probe sends a no-op heartbeat; see the methodology page for the exact payload. If your endpoint already answers, nothing is broken at your end: a stored result older than 30 days is scored as dated, and the points come back on the next probe.

Docs

pass Protocol version 10/10

Declares A2A 1.0 with supportedInterfaces[] (current v1 card shape).

info JWS signature 0/10

Card is unsigned (most published agents are).

pass Uptime track record 15/15

51/51 probes succeeded (100% uptime).

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` — `description` and `tags` are REQUIRED on AgentSkill since A2A v1.0, and tags are what discovery filters match on. 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

Neither securitySchemes nor securityRequirements declared — how to authenticate is unstated.

Activity (audit trail)

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

Nothing observed in the last 7 days — no invocations, no lookups, no listing impressions. Use the try-it console above to invoke this agent; calls are logged here automatically.

Card history

10 snapshots drifted 2× Every change to agent-card.json

Agent card snapshots
Captured	Hash	Snapshot
2026-10-03 23:22:32 current	`474bd39e0b09…`	view →
2026-10-01 20:36:48	`ca2685730a39…`	view →
2026-08-06 13:07:19	`27f8fee4d306…`	view →
2026-08-05 17:22:16	`27f8fee4d306…`	view →
2026-07-27 18:49:30	`27f8fee4d306…`	view →
2026-07-22 14:00:32	`27f8fee4d306…`	view →
2026-07-17 08:04:53	`27f8fee4d306…`	view →
2026-07-16 19:44:30	`27f8fee4d306…`	view →
2026-07-16 08:05:11	`27f8fee4d306…`	view →
2026-07-15 18:15:40	`27f8fee4d306…`	view →

Showing latest 10. The full snapshot history is on Pro (and free for the verified owner) via GET /api/agents/agents.sayerandstone.com/snapshots.

Uptime

100.0%

51 direct probes · 30d

Response

231ms

last direct probe

Skills

declared

Streaming

—

SSE-capable

Endpoints

Pricing x402 Self-declared · /.well-known/x402 Dispute or improve this rating

From $50.0000 per call

Endpoint	Price	Currency
`https://agents.sayerandstone.com/purchase`	50.0	USD

Try it ↗ Opens the operator's playground / docs in a new tab.

Settlement wallet: 0x92fb502e69fa86307869294209b03798e6fe217c on Base · basescan ↗

UCP merchant profile UCP 2026-08-25

Payment handlers: com.agentscore.payment.mpp com.agentscore.payment.stripe_spt com.agentscore.payment.x402

Services: dev.ucp.shopping/a2a

Read from /.well-known/ucp on 2026-10-06. Declared by the merchant; we have not placed an order.

Observed on-chain inflow verified on-chain

Last 7d

                  $0.00
                

0 transfers · synced 2026-10-25

Last 30d

                  $0.00
                

0 transfers · synced 2026-10-25

Last 90d PRO

Unlock with Pro

90-day total + 90 days of daily history

USDC inflows on Base. Reproducible via eth_getLogs on USDC Transfer events to the wallet. Inflow to a wallet, not proof that every transfer was a paid call.

Daily 30-day observed-inflow history

2026-09-25 2026-10-25

Last 30 days · 90 days with Pro Peak 30-day total: $0.00 Data points: 31 Total tx (30d window): 0

Agent card	`https://agents.sayerandstone.com/.well-known/agent-card.json`
Provider	https://agents.sayerandstone.com
Docs	https://agents.sayerandstone.com/llms.txt

Discovered via

agentic_market recrawl_warm recrawl_hot manifests mpp

Skills · 1 declared by this agent

These skills are declared by the agent. A taxonomy link appears only when we can classify a skill confidently.

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…

No taxonomy category yet

commercejewelryfine-jewelrylab-grownmade-to-order

Health · last 30 probes

When	HTTP	Live JSON-RPC	Latency
2026-10-25 15:50:06	200	—	231ms
2026-10-25 01:26:14	200	—	221ms
2026-10-24 12:51:50	200	—	152ms
2026-10-23 23:54:41	200	—	357ms
2026-10-23 11:12:01	200	—	219ms
2026-10-22 22:10:28	200	—	157ms
2026-10-22 08:22:55	200	—	159ms
2026-10-21 19:28:20	200	—	241ms
2026-10-21 06:34:26	200	—	536ms
2026-10-20 15:06:11	200	—	201ms

Who's calling this agent 30d

1 interactions captured (impressions + lookups + A2A calls)

By AI host (caller_kind) · top 3

PerplexityBot (crawler) 1 (100%)

Caller geography · top 3

US 1

Via which API surface · top 3

web 1

Public view: top 3 per dimension. Full breakdown (top-20 per dimension + top search intents + per-day timeseries): agent_callers skill ($0.05/call, $0 on Enterprise). Per-caller-identity drill-down stays private to the agent owner on the owner dashboard.

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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.

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 Shared Payment Token. Made to order.",
  "supportedInterfaces": [
    {
      "url": "https://agents.sayerandstone.com",
      "protocolBinding": "HTTP+JSON",
      "protocolVersion": "1.0"
    }
  ],
  "version": "1.0.0",
  "capabilities": {
    "extensions": [
      {
        "uri": "https://ucp.dev/2026-08-25/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 Shared Payment Token). Made to order.",
      "tags": [
        "commerce",
        "jewelry",
        "fine-jewelry",
        "lab-grown",
        "made-to-order"
      ]
    }
  ],
  "documentationUrl": "https://agents.sayerandstone.com/llms.txt"
}

Activity (audit trail)

Card history

Endpoints

Skills · 1 declared by this agent

Health · last 30 probes

Who's calling this agent 30d

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Audit-grade evidence bundle

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