Cn resident id parse

cn-resident-id-parse · version 1.0.0 · Identifiers & check digits · free, no key needed

Parse an 18-digit (or legacy 15-digit) Chinese resident ID: region code, birth date, sex and GB 11643-1999 check digit.

Use when you need to: parse a chinese id card number · validate a china resident identity card number · check digit for a PRC id number.

Decide before calling

Read the versioned contract and the supported scope below. Reuse cn-resident-id-parse@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 cn-resident-id-parse@1.0.0 for parse a chinese id card number. 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

• parse a chinese id card number
• validate a china resident identity card number
• check digit for a PRC id number
• extract birth date from chinese national id
• convert 15 digit chinese id to 18 digit
• GB 11643 id number checksum
• 身份证号码校验

Not supported

• looking up the administrative region name for the 6-digit region code (no GB/T 2260 lookup or region-name data)
• validating a national ID from any country other than China
• accepting a lowercase x in the 18th position or any whitespace/hyphen formatting

Behavior

• id must be exactly 15 ASCII digits (legacy form) or exactly 17 ASCII digits followed by a digit or uppercase X (18-digit form); anything else throws invalid_input. No trimming, case folding or separators.
• 15-digit input is upgraded to 17 digits by inserting '19' after the 6-digit region code (this tool assumes the 1900s century, since the 15-digit form predates the 2000s); 18-digit input's first 17 characters are used as-is.
• check_digit is always the GB 11643-1999 weighted mod-11 computation over the 17-digit payload (weights 7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2, remainder table 0..10 -> 1,0,X,9,8,7,6,5,4,3,2), independent of whether it matches the supplied 18th character.
• id18 preserves the original 18th character when one was supplied (even when it disagrees with check_digit); for 15-digit input, id18 uses the freshly computed check_digit, so a 15-digit input can never produce checksum_mismatch.
• birth_date is validated as a real proleptic Gregorian calendar date using the encoded 4-digit year (leap years: divisible by 4 and (not divisible by 100 or divisible by 400)); an invalid date reports birth_date: null and takes precedence over a checksum mismatch.
• sex is derived from the 17th character of the 17-digit payload (the last digit of the 3-digit sequence code): odd is male, even is female; this is always computed, regardless of date or checksum validity.
• region_code is the payload's first 6 characters returned unchanged; no administrative-division lookup is performed.
• Pure integer arithmetic and a fixed calendar rule; no locale, clock, or randomness; identical output across runs for the same input.

Input

• id (string, required): min length 15; max length 18; pattern ^(\d{15}|\d{17}[0-9X])$

Output

• valid (boolean, required)
• reason (one of null, "invalid_birth_date", "checksum_mismatch", required)
• region_code (string, required): pattern ^\d{6}$
• birth_date (string or null, required): pattern ^\d{4}-\d{2}-\d{2}$
• sex (one of "male", "female", required)
• check_digit (string, required): pattern ^[0-9X]$
• id18 (string, required): pattern ^\d{17}[0-9X]$

Limits

• max input bytes: 18

Example

Request input:

{
  "id": "11010519491231002X"
}

Response:

{
  "result": {
    "valid": true,
    "reason": null,
    "region_code": "110105",
    "birth_date": "1949-12-31",
    "sex": "female",
    "check_digit": "X",
    "id18": "11010519491231002X"
  }
}

How to call it

MCP

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

{
  "id": "cn-resident-id-parse",
  "version": "1.0.0",
  "input": {
    "id": "11010519491231002X"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/cn-resident-id-parse/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"id":"11010519491231002X"}'

The machine-readable contract is at /v1/tools/cn-resident-id-parse/versions/1.0.0.

CLI

node cli.mjs run cn-resident-id-parse 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Se personnummer parse: Parse a Swedish personnummer/samordningsnummer: resolve its century, return birth date, sex and Luhn validity.
• Isin validate: Validate a 12-character ISIN's ISO 6166 Luhn check digit and parse its country prefix, NSIN and NSIN scheme.
• Cusip validate: Validate a 9-character CUSIP's Modulus 10 Double Add Double check digit and parse its issuer, issue and PPN marker.
• Isin compute from nsin: Build a 12-character ISIN from a country prefix and a CUSIP/SEDOL national number, computing its Luhn check digit.
• Ismn validate: Validate an ISMN's EAN mod 10 check digit in M-form or 979-0 form and return the canonical 13-digit form.
• Issn validate: Validate an 8-digit ISSN's mod 11 check digit (X allowed) and compute its 977-prefixed EAN-13 barcode form.