💰 Paid API verification

promptshield.grindfree.net

promptshield.grindfree.net · promptshield.grindfree.net

Pay-per-request prompt-injection screener and HTML cleaner for AI agents. POST untrusted text or HTML to /v1/screen for a risk score plus sanitized text, or /v1/clean for HTML-to-LLM text. Catches hidden instructions, invisible unicode, markdown image exfil, and secret-exfil patterns. $0.002 USDC on Base via x402 v2. No API keys. Contact @grindfreelabs or rob@grindfree.net.

Trust score

60/100

grade C · 3 of 9 criteria apply

Uptime

not graded

catalogue listing · no agent card to probe

Observed inflow · 30d

not yet measured

wallet declared · scan pending

Dispute or improve this rating

C

Conformance score: 60/100

Catalogue listing, not an A2A agent: a paid API listed by agentic.market. Scored on the 3 criteria that apply (24 of 40 points, scaled to 100); the A2A card criteria do not apply.

Show breakdown Hide breakdown

partial Live endpoint 15/25

Our probe received an HTTP 402 payment challenge from the host: live, but paid.

partial Verified Identity 5/10

Provider declared: promptshield.grindfree.net (https://promptshield.grindfree.net). 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 4/5

seen in upstream source within 0d

n/a Agent card · Protocol version · JWS signature · Uptime track record · Skill declaration · Security declaration

Activity

last 24h · 0 invocations No personal data recorded

No activity in the last 7 days.

Listing history

1 snapshot

Snapshots

Agent card snapshots
Captured	Hash	Snapshot
2026-11-07 13:12:53 current	`b80141b372d3…`	view →

Endpoints

Pricing x402 on Base USDC Verified live · 402 challenge

From $0.0020 per call

Endpoint	Price	Currency
`https://promptshield.grindfree.net/v1/screen` Base · live 402	0.002	USDC
`https://promptshield.grindfree.net/v1/clean` Base · declared in manifest	—	USDC

Try it ↗

Settlement wallet: 0xe4b5827994b7b3cd38f9830d9ecf58b51b77721b on Base · basescan ↗

Listed by facilitators Coinbase CDP · 1

Observed on-chain inflow verified on-chain

Last 7d

                  $0.00
                

4 transfers · synced 2026-11-11

USDC on Base. Inflow to a wallet, not proof that every transfer was a paid call.

How it was settled and checked

x402-settled: $0.00 (0%) · 0 transfers sent by a known x402 facilitator

Other: $6.51 plain transfers sent by the payer · $0.00 other contract calls.

Cross-check: Coinbase's Bazaar reports 59 calls in 30 days across 8 resources; we observed 21 transfers (0 facilitator-settled) over 7 of 30 scanned days. Neither counter is assumed correct.

Reproducible via eth_getLogs on USDC Transfer events to the wallet. How we classify

Payment authenticity How we measure this →

Single payer observed 2/5

Payer identities observed; a single payer accounts for effectively all observed volume.

The settlement wallet is shared with other indexed agents, so inflow cannot be attributed to this agent alone.

$6.54 assessed 17 transactions 5/13 days active · 30d window Payer identities available

A low label reflects what we can observe, not a finding about the operator.

How this was checked

2 evidence caveats · measured 2026-11-11.
Checks: daily volume aggregate, active day cadence, amount regularity, spike concentration, settlement wallet overlap, payer uniqueness, payer concentration, payer recurrence, payer payee overlap.
Sources: agent revenue daily, agents payment wallet, agent payment transactions.

Payer concentration and 7 / 30 / 90-day windows: wallet_intel, payment_intelligence · included in Pro

Agent card	`https://promptshield.grindfree.net/`
Provider	https://promptshield.grindfree.net
Docs	https://promptshield.grindfree.net/v1/clean

Discovered via

cdp discovery agentic market

Health · last 1 probes

Probe log

When	HTTP	Live JSON-RPC	Latency
2026-11-08 21:24:20	404	—	—

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Embed a badge

Updates itself and links back here.

[![Agenstry grade](https://agenstry.com/badge/promptshield.grindfree.net.svg)](https://agenstry.com/agents/promptshield.grindfree.net)
[![Verified Business](https://agenstry.com/badge/promptshield.grindfree.net/identity.svg)](https://agenstry.com/agents/promptshield.grindfree.net)
[![Uptime](https://agenstry.com/badge/promptshield.grindfree.net/uptime.svg)](https://agenstry.com/agents/promptshield.grindfree.net)
[![A2A version](https://agenstry.com/badge/promptshield.grindfree.net/protocol.svg)](https://agenstry.com/agents/promptshield.grindfree.net)

Audit evidence

JSON for vendor reviews. Signed copy verifies against our JWKS.

audit.json audit.json (JWS-signed) verification history

Raw agent card JSON

{
  "_source": "agentic.market",
  "service": {
    "id": "promptshield-grindfree-net",
    "name": "promptshield.grindfree.net",
    "description": "",
    "domain": "promptshield.grindfree.net",
    "provider": "promptshield.grindfree.net",
    "providerUrl": "",
    "category": "",
    "networks": [
      "Base"
    ],
    "enriched": false,
    "endpoints": [
      {
        "url": "https://promptshield.grindfree.net/v1/clean",
        "description": "Convert HTML to clean LLM-ready text: strips scripts/styles/hidden elements/zero-width chars; returns text + token estimate.",
        "pricing": {
          "amount": "0.002",
          "currency": "USDC",
          "network": "eip155:8453",
          "scheme": "exact",
          "maxAmount": "",
          "minAmount": ""
        },
        "method": "POST",
        "providerName": "",
        "parameters": [
          {
            "group": "body",
            "name": "content",
            "type": "string",
            "description": "",
            "example": "<html><body><p>Hello agent</p></body></html>",
            "enumValues": [],
            "default": null,
            "required": false
          }
        ],
        "serviceName": "PromptShield",
        "tags": [
          "security",
          "prompt-injection",
          "agents",
          "x402"
        ],
        "quality": {
          "l30DaysTotalCalls": "7",
          "l30DaysUniquePayers": "4"
        }
      }
    ],
    "integrationType": "",
    "isNew": false,
    "priceSummary": {
      "minAmount": "0.002",
      "maxAmount": "0.002",
      "avgCostPerTransaction": "0.002",
      "avgCostBasis": "exact",
      "currency": "USDC"
    },
    "serviceName": "PromptShield",
    "tags": [
      "security",
      "prompt-injection",
      "agents",
      "x402"
    ],
    "iconUrl": ""
  }
}