Apex Agent Tool Result Contract Validator

apex-agent-tool-result-validator.apex-ai-assets.workers.dev

Checks the result an AI agent or MCP tool returns against the Agent Tool Result Envelope v1.0 contract (schema version, tool name, ok or error status, request ID, RFC 3339 timestamp and an object payload) and gives back deterministic, normalized JSON errors for contract tests and test fixtures. A free validation route is also available. A plain HTTP API paid per call in USDC via x402, not an MCP server.

Visit Apex Agent Tool Result Contract Validator

Crypto payment details

Payment protocol: x402
Networks: Base
Tokens: USDC
Price per paid call: $0.005 per validation, USDC on Base via x402 v2 exact. The provider's /.well-known/x402.json lists one Base mainnet paid route: the xpay lane, GET /v1/premium/mainnet/xpay/validate (one envelope per call). Other mainnet paths (the generic, PayAI and batch routes) are not listed in the provider's manifest, so we don't present them as buying options. Free validation at /v1/validate; /v1/premium/validate is a Base Sepolia testnet route (test USDC only). Prices from our unpaid 402 probes and the provider's /.well-known/x402.json, 2026-11-02
Example paid endpoint: https://apex-agent-tool-result-validator.apex-ai-assets.workers.dev/v1/premium/mainnet/xpay/validate?payload=%7B%22schema_version%22%3A%221.0%22%2C%22tool_name%22%3A%22inventory_lookup%22%2C%22status%22%3A%22ok%22%2C%22request_id%22%3A%22req_123%22%2C%22timestamp%22%3A%222026-10-30T00%3A00%3A00Z%22%2C%22payload%22%3A%7B%22sku%22%3A%22demo-001%22%2C%22available%22%3Atrue%7D%7D
Input schema (OpenAPI): https://apex-agent-tool-result-validator.apex-ai-assets.workers.dev/openapi.json
How to call it: Every validate route, paid and free, requires the query parameter payload: one Agent Tool Result Envelope v1.0 as URL-encoded JSON, up to 8,000 characters. The example above is the provider's own runnable sample (their sample envelope, URL-encoded). A missing or malformed payload gets HTTP 400 before any payment is asked for. The provider's manifest lists no batch route. Our check is an unpaid 402 quote probe, not a paid-delivery test: it confirms the price and payment terms, not the result you get after paying. The free /v1/validate route takes the same payload parameter, so you can check an envelope's shape there before paying.
Also listed on: PayAPI Market, public listing
Category: Developer Tools & Infrastructure · compare developer tools & infrastructure
More tools on: Base
Related guides: How to accept USDC for your API (pay-per-call with x402) · Paid MCP servers that accept USDC: x402 pay-per-call MCP tools for AI agents · How to pay for an API with USDC via x402 (step by step) · x402 vs API keys for AI agents: which should your agent use? · x402 API prices per call, by category

Public statsmeasured by YourAITools

Measuring since Nov 2, 2026: 9 daily checks so far, so these numbers are still thin.

Status at last check: Up; Answered below HTTP 500
Measuring since: Nov 2, 2026
Last check: Nov 10, 2026, 2:10 AM ET
HTTP status: 402
Valid x402 payment terms: Yes
x402 version: v2
Response time: 210 ms; Time to response headers
Listed price: $0.005
Price seen in the 402: $0.005 on Base; Inside the listed price range
Uptime, last 7 days: 100%; 7 of 7 daily checks up · valid x402 100%
Uptime, last 30 days: 100%; 9 of 9 daily checks up · valid x402 100%

Trust score100/100Strong

From 8 daily checks since Nov 3, 2026, last 30 days. Formula 1.0-median30.

Uptime, last 30 days: 100%40 / 40 pts
Valid x402 payment request: 100%40 / 40 pts
Price matches the listing: Yes10 / 10 pts
Median response time (up checks): 199 ms10 / 10 pts

How the score works: uptime (40 points), how often the endpoint returned a valid x402 payment request (40), whether the price in it matches the listed price (10) and median response time of the up checks (10: under 500 ms 10, 500–999 ms 7, 1–2 s 4, slower 1, 0 if the last check was not up). Parts that can’t apply are left out and the score is rescaled. Strong is 90–100, fair 70–89, weak under 70. Paying for Featured, Sponsored or any placement never changes it, and it is not an endorsement. Think it’s wrong? Email hello@youraitools.co and we’ll re-check it.

How we measure: one unpaid check per day of the listing’s example endpoint (GET https://apex-agent-tool-result-validator.apex-ai-assets.workers.dev/v1/premium/mainnet/xpay/validate?payload=%7B%22schema_version%22%3A%221.0%22%2C%22tool_name%22%3A%22inventory_lookup%22%2C%22status%22%3A%22ok%22%2C%22request_id%22%3A%22req_123%22%2C%22timestamp%22%3A%222026-10-30T00%3A00%3A00Z%22%2C%22payload%22%3A%7B%22sku%22%3A%22demo-001%22%2C%22available%22%3Atrue%7D%7D). We never pay and never send a payment header. Up means any answer below HTTP 500 except 404/410 within 8 seconds. Uptime counts those daily checks. Payment never changes these numbers. A technical check, not an endorsement. Raw JSON · schema

How we verified it

Requested by the provider, Apex AI Assets, by email to hello@youraitools.co on 2026-11-02 (free listing; no paid placement). Re-checked 2026-11-02 at 6:23 PM ET after the provider redeployed: its /.well-known/x402.json lists exactly one Base mainnet paid resource, the xpay lane GET /v1/premium/mainnet/xpay/validate with a runnable ?payload= sample, plus a Base Sepolia testnet route. An unpaid call to that sample URL returned HTTP 402 with x402 v2 terms: exact, 0.005 USDC on Base (eip155:8453). A missing or malformed payload returned HTTP 400 before any payment was asked for. The generic /v1/premium/mainnet/validate and the PayAI lane still answer with a 402 quote at the same price, but neither is in the manifest (the provider's OpenAPI says the generic route stays unlisted until its CDP facilitator is configured). The batch-validate paths no longer accept a payloads array (HTTP 400). The free /v1/validate route returned valid: true for the sample envelope. Input schema from the provider's OpenAPI. Nothing paid. Last checked 2026-11-02.

The description summarizes the provider's own site. YourAITools is not affiliated with Apex Agent Tool Result Contract Validator. Listing a tool is not an endorsement: check pricing and terms with the provider before paying.

Some links are affiliate links; we may earn a commission at no cost to you. It never affects listings or order. How we make money

Is this your tool? Update the listing for free, or get it Featured for 30 days ($29, card or USDC): a badge and a labeled slot at the top of its category. Check your x402 endpoint free.

Own Apex Agent Tool Result Contract Validator? Add a “Listed on YourAITools” badge

Free, optional, no tracking. Paste one of these into your site or README:

<a href="https://youraitools.co/tool/apex-agent-tool-result-validator"><img src="https://youraitools.co/badge/listed.svg" alt="Listed on YourAITools" width="168" height="20"></a>

[![Listed on YourAITools](https://youraitools.co/badge/listed.svg)](https://youraitools.co/tool/apex-agent-tool-result-validator)

Accepts crypto? Use the “Pays in crypto” badge instead.

Building or using tools like this? Discuss them in the YourAITools Community.

Apex Agent Tool Result Contract Validator

Crypto payment details

Public statsmeasured by YourAITools

How we verified it

More in Developer Tools & Infrastructure

402rpc

AgentBodega

ai-mail.sh