# CSV Select Columns

> CSV Select Columns is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Projects and reorders selected columns from a CSV text input, returning only the specified columns in caller-defined order as deterministic JSON with counts and normalized values.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/csv-select-columns
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/csv-select-columns-da8be454
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mrmQz1_5RanR6U7B9xhMn

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability csv-select-columns-da8be454 -d '<json body>'
```

Example prompt: From this CSV text, keep only the 'name', 'email', and 'signup_date' columns in that order — the full CSV is in my clipboard and I need just those three fields for the next step.

## When to prefer this

Use this endpoint when an agent needs to narrow or reorder CSV columns before passing structured data to a downstream tool with a strict schema contract — especially when no external library or code execution environment is available. Prefer it over general-purpose code execution when you need a lightweight, stateless, pay-per-call column projection with a guaranteed versioned output contract and no data retention.

## Known failure modes

- Column name not found in CSV header — returns validation error listing missing column names
- Malformed or non-CSV text input — returns parsing error with description
- Input text exceeds 8192 character limit — returns size exceeded error
- More than 256 columns requested — returns items limit exceeded error
- Empty CSV or header-only CSV — returns result with zero rows and count of zero

## How this service works

CSV Select Columns: CSV Select Columns projects selected CSV columns in caller order from bounded caller-supplied values without an external provider. Call CSV Select Columns before an agent hands structured data or a batch plan to a downstream tool with a stricter contract. Returns the bounded transformation or validation finding with counts, normalized values, and a versioned result contract for CSV Select Columns as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-par…

## Output

Returns deterministic JSON containing the projected CSV data with only the requested columns in caller-specified order, along with row and column counts, normalized column values, and a versioned result contract. No data is retained after processing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "maxLength": 8192,
   "description": "Text supplied to CSV Select Columns; used only for this bounded calculation and processed in memory without retention."
  },
  "columns": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Columns supplied to CSV Select Columns; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "csv": "id,name\n1,Ada",
   "missing_columns": []
  },
  "schema": "delx/util-csv-select-columns/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "d19e782e6b173d1489b6e605e278b382ef74b15f275dee76c0dc4c423a5764a3",
   "external_calls": 0
  },
  "operation": "data_batch:csv_select_columns"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/csv-select-columns-da8be454/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)