duet-csv-preflight

Duet CSV Preflight

Use this skill when a workflow is about to import or write CSV data into a spreadsheet, database, CRM, ETL pipeline, migration job, or another system where malformed or risky rows could create errors, duplicates, or unsafe spreadsheet behavior.

Do not use this skill merely because a file has a .csv extension. Use it when there is a meaningful downstream import/write action and a deterministic preflight can reduce failure risk.

Service

• Endpoint: POST https://duet-csv-preflight.projectlantern-review.workers.dev/v1/preflight
• Content-Type: application/json
• Price: $0.005 USDC per successful paid call
• Network: Base mainnet (eip155:8453)
• Payment protocol: x402 v2
• Input retention: none advertised by the service

What it checks

The service detects import hazards including:

• row-width mismatches
• blank required values
• duplicate rows
• blank or duplicate keys
• outer whitespace
• formula-like cells
• structural CSV errors

Decision rule

Run preflight immediately before the downstream import/write boundary.

1. Build a JSON body with the raw CSV text.
2. Add requiredFields when the downstream target requires named columns.
3. Add keyField when duplicate or blank identifiers would be harmful.
4. Send the paid POST through an x402-capable buyer path.
5. Inspect the returned summary and findings.
6. Do not continue the downstream import when structural errors or material validation errors are reported unless the human/operator explicitly chooses to override them.
7. Never manufacture a payment receipt or treat an unpaid HTTP 402 challenge as a successful validation.

Request shape

{
  "csv": "id,name\n1,Alice\n",
  "requiredFields": ["id"],
  "keyField": "id"
}

Optional delimiter values are comma, semicolon, or tab.

Payment and discovery

Prefer an already-authorized x402 buyer tool. Do not expose or request wallet private keys.

If the runtime uses MCP and lacks a direct x402 buyer, it can search the PayAPI Market MCP catalogue at:

https://payapi.market/mcp

The origin also publishes current machine-readable metadata at:

• /.well-known/x402
• /openapi.json
• /llms.txt

See references/x402.md for protocol notes and references/workflow-patterns.md for integration patterns.

Attribution discipline

A call made by the Astra Duet project, Tim, ChatGPT, a project-created agent, or a marketplace verification bot is not unrelated customer demand. Do not describe project-controlled or verification activity as organic usage.