Unique key claim check

unique-key-claim-check · version 1.0.0 · Numbers & math · free, no key needed

Check an exact uniqueness claim and first-duplicate certificate under an explicit SQL null policy.

Use when you need to: check claimed unique key · validate uniqueness certificate · verify first duplicate claim.

Decide before calling

Read the versioned contract and the supported scope below. Reuse unique-key-claim-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 unique-key-claim-check@1.0.0 for check claimed unique key. 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 claimed unique key
• validate uniqueness certificate
• verify first duplicate claim
• audit unique constraint result
• check SQL null uniqueness
• test composite uniqueness claim

Not supported

• modify or repair source rows
• infer columns or null policy
• execute SQL or access a database

Behavior

• Rows are scanned in ascending source index; columns retain caller order.
• Cell equality is type-strict over null, booleans, safe integers other than -0, and Unicode strings by code point sequence.
• A well-typed false claim returns valid false and the first field discrepancy; malformed input throws.
• reference_version identifies ISO/IEC 9075-2:2023 §4.18, §11.8, and §11.9 narrowed by the packet README.

Input

• rows (array of object, required): max items 1000
• columns (array of string, required): min items 1; max items 16; each min length 1; each max length 1024
• null_policy (one of "nulls_distinct", "nulls_equal", "reject", required)
• claim (object, required)

Output

• valid (boolean, required)
• reason (string, required)
• discrepancy (null or object, required)
• reference_version (constant "ISO/IEC 9075-2:2023 §4.18, §11.8, §11.9 (narrowed profile)", required)

Limits

• max input bytes: 262144
• max rows: 1000
• max columns: 16
• max cell string bytes: 1024

Example

Request input:

{
  "rows": [
    {
      "id": 1
    },
    {
      "id": 2
    }
  ],
  "columns": [
    "id"
  ],
  "null_policy": "nulls_distinct",
  "claim": {
    "unique": true,
    "duplicate": null
  }
}

Response:

{
  "result": {
    "valid": true,
    "reason": "claim_exact",
    "discrepancy": null,
    "reference_version": "ISO/IEC 9075-2:2023 §4.18, §11.8, §11.9 (narrowed profile)"
  }
}

How to call it

MCP

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

{
  "id": "unique-key-claim-check",
  "version": "1.0.0",
  "input": {
    "rows": [
      {
        "id": 1
      },
      {
        "id": 2
      }
    ],
    "columns": [
      "id"
    ],
    "null_policy": "nulls_distinct",
    "claim": {
      "unique": true,
      "duplicate": null
    }
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/unique-key-claim-check/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"rows":[{"id":1},{"id":2}],"columns":["id"],"null_policy":"nulls_distinct","claim":{"unique":true,"duplicate":null}}'

The machine-readable contract is at /v1/tools/unique-key-claim-check/versions/1.0.0.

CLI

node cli.mjs run unique-key-claim-check 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Foreign key claim check: Check an exact referential-inclusion claim and first violation under an explicit composite-null policy.
• Candidate key claim check: Check an exact candidate-key claim, including uniqueness and minimality, under an explicit SQL null policy.
• Dedupe first check: Check an exact first-wins SameValueZero deduplication claim and report its first discrepancy.
• 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.