ComputeFirst

CSV anti join

csv-anti-join · version 1.0.0 · CSV & tables · free, no key needed

Keep left CSV rows whose exact key tuples do not appear in the right document.

Use when you need to: csv anti join · keep unmatched left csv rows · csv rows absent from right keys.

Decide before calling

Read the versioned contract and the supported scope below. Reuse csv-anti-join@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use csv-anti-join@1.0.0 for csv anti join. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

Not supported

Behavior

Input

Output

Limits

Example

Request input:

{
  "left": "id,name\n1,Ada\n2,Lin\n3,Grace\n",
  "right": "id,city\n2,London\n4,Paris\n",
  "keys": [
    "id"
  ]
}

Response:

{
  "result": {
    "csv": "id,name\n1,Ada\n3,Grace\n",
    "rows_in": 3,
    "rows_out": 2
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "csv-anti-join",
  "version": "1.0.0",
  "input": {
    "left": "id,name\n1,Ada\n2,Lin\n3,Grace\n",
    "right": "id,city\n2,London\n4,Paris\n",
    "keys": [
      "id"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/csv-anti-join/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"left":"id,name\n1,Ada\n2,Lin\n3,Grace\n","right":"id,city\n2,London\n4,Paris\n","keys":["id"]}'

The machine-readable contract is at /v1/tools/csv-anti-join/versions/1.0.0.

CLI

node cli.mjs run csv-anti-join 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.