Dedupe first check

dedupe-first-check · version 1.0.0 · Numbers & math · free, no key needed

Check an exact first-wins SameValueZero deduplication claim and report its first discrepancy.

Use when you need to: check first deduplication claim · validate first duplicate removal · audit first unique result.

Decide before calling

Read the versioned contract and the supported scope below. Reuse dedupe-first-check@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 dedupe-first-check@1.0.0 for check first deduplication claim. 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

• check first deduplication claim
• validate first duplicate removal
• audit first unique result
• find first first dedupe error
• verify ordered first deduplication
• compare claimed first unique list

Not supported

• compute and return a replacement claim
• deduplicate objects or arrays as scalar values
• apply Unicode or numeric coercion

Behavior

• It verifies that only the earliest occurrence of each value remains, in source order.
• Values are JSON scalars: null, booleans, strings, and safe integers except negative zero; types remain distinct.
• A false claim is never repaired; the lowest claim index that differs is returned.
• Empty arrays are allowed. Strings are compared exactly without normalization.

Input

• source (array of null or boolean or integer or string, required): max items 10000
• claim (array of null or boolean or integer or string, required): max items 10000

Output

• valid (boolean, required)
• reason (one of "value_mismatch", "length_mismatch", optional)
• discrepancy (object, optional)
• reference_version (constant "ECMA-262-2026-SameValueZero-Map", required)

Limits

• max items: 10000
• max string bytes: 4096
• max input bytes: 1000000

Example

Request input:

{
  "source": [
    "a",
    "b",
    "a",
    null,
    null
  ],
  "claim": [
    "a",
    "b",
    null
  ]
}

Response:

{
  "result": {
    "valid": true,
    "reference_version": "ECMA-262-2026-SameValueZero-Map"
  }
}

How to call it

MCP

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

{
  "id": "dedupe-first-check",
  "version": "1.0.0",
  "input": {
    "source": [
      "a",
      "b",
      "a",
      null,
      null
    ],
    "claim": [
      "a",
      "b",
      null
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/dedupe-first-check/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"source":["a","b","a",null,null],"claim":["a","b",null]}'

The machine-readable contract is at /v1/tools/dedupe-first-check/versions/1.0.0.

CLI

node cli.mjs run dedupe-first-check 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Dedupe keyed check: Check an exact keyed Map deduplication claim and report its first discrepancy.
• Dedupe last check: Check an exact last-wins SameValueZero deduplication claim and report its first discrepancy.
• Join inner result check: Check a claimed ordered inner join index result and report its first discrepancy.
• Join left result check: Check a claimed ordered left join index result and report its first discrepancy.
• Join semi result check: Check a claimed ordered semi-join index result and report its first discrepancy.
• Unique key claim check: Check an exact uniqueness claim and first-duplicate certificate under an explicit SQL null policy.