# Delx Commerce CSV Left Join By Key

> Delx Commerce CSV Left Join By Key is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Performs a left join on two CSV datasets using a specified key column, returning merged rows in-memory without data retention.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/csv-left-join-by-key?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-csv-left-join-by-key-41080422
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b6BgnFIsdTPguN3fw6IF8

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 delx-commerce-csv-left-join-by-key-41080422 -d '<json body>'
```

Example prompt: I have two CSV datasets — one with user IDs and names, and another with user IDs and scores — can you left-join them on the 'id' column so I get a single merged CSV with all columns?

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-use, no-signup CSV left join that runs in memory with verifiable non-retention guarantees — ideal for agents handling sensitive tabular data that must not be stored, or when you want exact per-call USDC micropayment pricing without subscription overhead.

## Known failure modes

- Missing or mismatched key column name causes empty or null join results
- Input CSV strings exceeding 8192 characters are rejected
- Malformed CSV input (inconsistent columns, unescaped commas) may cause parse errors
- Key column not present in one or both CSVs results in unjoined output
- Payment failure via x402 prevents execution

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object containing a merged CSV string (result.csv) with all left-hand rows and matching columns from the right CSV, the total row count, an operation status ('pass'), and a verifiable evidence block confirming no data was retained and no external calls were made (includes input SHA-256 hash).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string",
   "maxLength": 8192,
   "description": "Key supplied to CSV Left Join By Key; used only for this bounded calculation and processed in memory without retention."
  },
  "left": {
   "type": "string",
   "maxLength": 8192,
   "description": "Left supplied to CSV Left Join By Key; used only for this bounded calculation and processed in memory without retention."
  },
  "right": {
   "type": "string",
   "maxLength": 8192,
   "description": "Right supplied to CSV Left Join By Key; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "csv": "id,name,score\n1,Ada,10\n2,Lin,",
   "row_count": 2
  },
  "schema": "delx/util-csv-left-join-by-key/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "fc7b0105dea0cd7ff481614e8ba999b4ca60e2975a5ef301fc7efdbece9ea9cc",
   "external_calls": 0
  },
  "operation": "data_batch:csv_left_join_by_key"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-csv-left-join-by-key-41080422/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)