# PayloadPier

Supplier Price Compare detects exact-SKU price, pack-size, unit-cost, minimum-order and optional product gross-margin changes in two buyer-supplied snapshots. Inputs: JSON, CSV or XLSX. No supplier search, scraping, fuzzy matching, OCR or currency conversion.

## Machine-readable discovery
- [Access methods, payment terms and input example](https://payloadpier.com/api/discovery)
- [MCP registry manifest](https://payloadpier.com/server.json)

## Public documentation
- [Overview and pricing](https://payloadpier.com/portal)
- [Free fixed sample](https://payloadpier.com/)
- [Use case and synthetic worked example](https://payloadpier.com/learn/supplier-pack-size-changes)
- [First request](https://payloadpier.com/start)
- [OpenAPI](https://payloadpier.com/api/openapi.json)
- [Python and Node clients](https://payloadpier.com/docs/agents)
- [MCP](https://payloadpier.com/docs/mcp)
- [x402 payments](https://payloadpier.com/docs/x402)
- [Terms and refunds](https://payloadpier.com/terms)
- [Privacy](https://payloadpier.com/privacy)
- [Support](https://payloadpier.com/contact)

## Access paths
REST: POST https://payloadpier.com/api/v1/compare, scoped X-API-Key plus Idempotency-Key. Create an account with an email address and password at https://payloadpier.com/sign-up. Account keys remain supported for existing accounts. Successful comparisons consume one included subscription unit or USD 0.25 prepaid credit. Published monthly plans: USD 9/50 comparisons, USD 19/200 or USD 49/1,000; additional calls use prepaid credit. USD 5 and USD 10 prepaid top-ups available. Free own-JSON local comparison tester: https://payloadpier.com/portal#docs (browser calculation, not authenticated API access).

API-key MCP: https://payloadpier.com/api/mcp, Authorization: Bearer API_KEY. Tools: compare_supplier_prices, get_account_balance, get_referral_link, claim_referral. Comparison requires a durable operation_id. Referral tools require their own scope.


x402: POST https://payloadpier.com/api/x402/compare, JSON plus Idempotency-Key, 0.25 USDC on Base mainnet (eip155:8453). The 402 response supplies the exact payment terms and quote resource. Testnet settlement was verified; the first genuine mainnet payment remains unverified. This is separate from API-key prepaid billing.

## Operational limits
At most 5,000 rows per snapshot, 2 MiB per file, 5 MiB per request. Exact text SKUs, decimal-string money, explicit currency and units. Invalid inputs are not billed. Authenticated calls have an account-wide rate limit. MCP/x402 also have public endpoint limits. HTTP 429 includes Retry-After.

Source files and comparison results are processed in memory; billing metadata persists. Recorded operation replays return 409 without another charge and without the original result. Timeout outcomes require reconciliation, not a new operation ID. Product gross margin excludes taxes, freight, fees and overhead. No uptime SLA is offered.

Account: https://payloadpier.com/account
Pricing: https://payloadpier.com/pricing
Documentation: https://payloadpier.com/docs
OAuth MCP client discovery remains unverified. Use scoped API-key MCP when supported.