CSV Regression Fixtures 1.0.0

Check your importer against 24 original synthetic CSV cases with explicit expected values. Use them when changing a parser, ETL pipeline or data-quality report.

Unpaid quote verified on 21 October 2026. The ZIP endpoint is live for compatible x402 v2 clients. A completed paid download has not been verified.

Free preview	Full pack — 5.00 USDC
Three unchanged cases: multiline fields, blank versus missing cells, and UTF-8 BOM. Includes the reference validator, manifest, schema and MIT license.	All 24 cases, explicit expected results, generator, validator, tests and reproducible release builder. The same MIT license permits commercial use, modification and redistribution with its notice.

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Coverage includes quoted commas and newlines, escaped quotes, empty/missing/surplus cells, duplicate headers and records, Unicode, BOM, tab/semicolon dialects, malformed quoting and application-limit boundaries. Each manifest declares its delimiter and decoding policy. Expected results use a documented Python CSV parsing profile; other parsers can differ on malformed input and blank records.

Run the preview

Extract the ZIP and run this command from its folder. Python 3.10+ and its standard library are sufficient; the validator runs offline.

python3 validate.py

Developer checkout with x402 v2

The full pack is offered as a single ZIP download for 5.00 native USDC on Base. Use a compatible wallet-aware x402 v2 client. An ordinary browser or unsigned curl request receives a payment quote as JSON; it does not download the ZIP.

Request the exact download URL without payment to inspect its 402 Payment Required quote.
Review the quoted resource, token, network, amount and recipient in your wallet/client. It signs the exact payment authorization locally. This server never asks for a wallet seed phrase or private key.
The client repeats the same GET with its PAYMENT-SIGNATURE header. It must preserve the quoted x402 v2 resource, accepted requirement and extensions.
After a positive settlement acknowledgement, the response is 200 application/zip with a PAYMENT-RESPONSE receipt header. Save the ZIP and retain that receipt and authorization for recovery. A matching already-settled authorization can retrieve the same archive without another settlement.

Use the challenge-bound x402 authorization: a standalone token transfer does not supply this API’s proof of payment. The price above is the token amount; review any additional wallet or network costs before authorizing.

Inspect an unpaid quote

This example sends no payment header and makes no wallet call. The verified response is 402. The output file is JSON, not a ZIP archive.

curl --silent --show-error --request GET \
  --dump-header quote.headers \
  --output quote.json \
  'https://172-93-215-200.sslip.io/api/csv-fixtures/v1.0.0/download.zip'

The PAYMENT-REQUIRED header contains the Base64-encoded x402 challenge. The JSON body describes the same challenge. Inspect the HTTP status before treating any response as a download.

Resource and client compatibility details

Method	`GET`, no request body
Exact resource URL	`https://172-93-215-200.sslip.io/api/csv-fixtures/v1.0.0/download.zip`
Network	Base mainnet, `eip155:8453`
Asset	Native USDC, `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`
Amount	`5000000` atomic units = 5.00 USDC
Recipient	`0x781eb433ff788705080254c6f510df16d37b0c44`
Protocol	x402 v2 exact EVM authorization. The endpoint requires decimal-string value/time fields and a short authorization window: at evaluation, `validAfter < now < validBefore <= now + 60 seconds`. Client defaults may need adjustment.
Successful body	`application/zip`, file `csv-fixtures-full-1.0.0.zip`, 59,909 bytes
Archive SHA-256	`745452add2384e18b4a9b46cdb4a67c8495f443355c93b3b28fee1f647f0dd7f`

If payment times out or the outcome is uncertain, keep the authorization and receipt details and seek recovery before authorizing another payment. A 409 can mean an authorization was already attempted or bound to a different resource; a 503 can mean an uncertain payment outcome. Neither establishes that another payment is needed.

This guide does not connect to a wallet or call the API. A compatible paid-client integration and completed purchase are not yet verified. Protocol background: x402 payment flow. Token reference: Circle’s USDC contract addresses.