Array set difference

array-set-difference · version 1.0.0 · Other utilities · free, no key needed

Return unique left-array values absent from the right array, in first-seen order.

Use when you need to: ordered array set difference · values in left but not right · subtract one JSON array from another.

Decide before calling

Read the versioned contract and the supported scope below. Reuse array-set-difference@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 array-set-difference@1.0.0 for ordered array set difference. 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

• ordered array set difference
• values in left but not right
• subtract one JSON array from another
• remove matching values from array
• JSON array difference preserving order
• find items absent from second array

Not supported

• symmetric difference
• multiset subtraction

Behavior

• All outputs include standard_version.
• Input order is preserved when the result is set-like.
• Integers, decimal strings, and strings are compared without binary floating-point conversion.
• Pure synchronous processing with first-occurrence result ordering.

Input

• left (array of any JSON value, required): max items 256
• right (array of any JSON value, required): max items 256

Output

• standard_version (constant "RFC8785", required)
• values (array of any JSON value, required): max items 256

Limits

• max input bytes: 32768
• max items: 256
• max iterations: 4095
• max output bytes: 32768

Example

Request input:

{
  "left": [
    1,
    2,
    2,
    3
  ],
  "right": [
    2
  ]
}

Response:

{
  "result": {
    "standard_version": "RFC8785",
    "values": [
      1,
      3
    ]
  }
}

How to call it

MCP

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

{
  "id": "array-set-difference",
  "version": "1.0.0",
  "input": {
    "left": [
      1,
      2,
      2,
      3
    ],
    "right": [
      2
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/array-set-difference/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"left":[1,2,2,3],"right":[2]}'

The machine-readable contract is at /v1/tools/array-set-difference/versions/1.0.0.

CLI

node cli.mjs run array-set-difference 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

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