Array duplicates find

array-duplicates-find · version 1.0.0 · Other utilities · free, no key needed

List duplicated JSON values with counts and first indexes, preserving first-seen order.

Use when you need to: find duplicate values in JSON array · list duplicates with counts · get repeated items and first indexes.

Decide before calling

Read the versioned contract and the supported scope below. Reuse array-duplicates-find@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-duplicates-find@1.0.0 for find duplicate values in JSON array. 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

• find duplicate values in JSON array
• list duplicates with counts
• get repeated items and first indexes
• count duplicate array values
• identify repeated JSON objects
• show duplicate positions in array

Not supported

• deduplicate the input array
• fuzzy or normalized equality

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

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

Output

• standard_version (constant "RFC8785", required)
• duplicates (array of object, required): max items 256

Limits

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

Example

Request input:

{
  "values": [
    1,
    "1",
    1,
    {
      "b": 2,
      "a": 1
    },
    {
      "a": 1,
      "b": 2
    }
  ]
}

Response:

{
  "result": {
    "standard_version": "RFC8785",
    "duplicates": [
      {
        "value": 1,
        "count": 2,
        "first_index": 0
      },
      {
        "value": {
          "b": 2,
          "a": 1
        },
        "count": 2,
        "first_index": 3
      }
    ]
  }
}

How to call it

MCP

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

{
  "id": "array-duplicates-find",
  "version": "1.0.0",
  "input": {
    "values": [
      1,
      "1",
      1,
      {
        "b": 2,
        "a": 1
      },
      {
        "a": 1,
        "b": 2
      }
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/array-duplicates-find/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"values":[1,"1",1,{"b":2,"a":1},{"a":1,"b":2}]}'

The machine-readable contract is at /v1/tools/array-duplicates-find/versions/1.0.0.

CLI

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

Get the client at /clients/cli/.

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