ReturnCheck — Verified return-policy API for AI shopping agents

Can this specific product actually be returned? ReturnCheck answers that one question for AI shopping agents, with a verified verdict — not a guess.

Give it a product_url and a buyer_country and it returns a verdict (YES / YES_WITH_CONDITIONS / NO / UNKNOWN) with the exact policy clause quoted from the page, the source URL, the return window, and a confidence score. If it cannot verify a clause on the page, it returns UNKNOWN — it never invents.

Built for agent-to-agent commerce: an MCP tool plus x402-friendly micro-pricing at $0.02 per verified answer (UNKNOWN is free; a keyless free trial is available).

Why it exists

AI agents are starting to buy things. Before they buy, they need to know if a purchase is reversible — and today no one answers "is this returnable?" in a way a machine can trust and act on. ReturnCheck is the neutral verification primitive for that: it sells to every shopping agent and competes with none of them.

Related MCP server: Periskop MCP Server

Quick start

MCP (Streamable HTTP) — tool: check_return

https://returncheck.m-angelmartinez-fer.workers.dev/mcp

HTTP

curl -X POST https://returncheck.m-angelmartinez-fer.workers.dev/v1/check \
  -H "content-type: application/json" \
  -d '{"product_url":"https://store.example/p/shoe","buyer_country":"US","item_condition":"unopened"}'

If you already have the product/policy page rendered, pass it as page_html or page_text — ReturnCheck verifies against it and skips fetching (best coverage, bypasses sites that block server-side reads). It still never invents.

What you get back

{
  "verdict": "YES_WITH_CONDITIONS",
  "returnable": true,
  "confidence": 0.9,
  "policy": { "merchant_return_days": 30, "return_category": "FiniteReturnWindow" },
  "evidence": {
    "source_url": "https://store.example/policies/refund-policy",
    "exact_clause": "Items may be returned within 30 days of delivery for a full refund.",
    "verified_on": "2026-08-23"
  }
}

Pricing

Discovery for agents

• OpenAPI: /openapi.json

• Plugin manifest: /.well-known/ai-plugin.json

• Agents manifest: /agents.json

• LLM manifest: /llms.txt

• MCP tool list: /mcp

Design principles

• Never invent. Every determinate verdict carries a clause verified literally against the page. If it can't be verified, the answer is UNKNOWN.

• Frozen contract (v1.0). Fields are only ever added, never broken.

• US data first, global architecture. Runs 100% serverless on the edge (Cloudflare Workers + D1 + Workers AI).

Keywords

return policy API · returns verification · AI shopping agents · agentic commerce · MCP server · check_return · x402 · agent-to-agent payments · e-commerce returns · is this returnable · refund policy checker