Figi validate

figi-validate · version 1.0.0 · Identifiers & check digits · free, no key needed

Validate a 12-character FIGI's structure, forbidden-prefix rule and Modulus 10 Double Add Double check digit.

Use when you need to: validate a figi · check figi check digit · is this figi valid.

Decide before calling

Read the versioned contract and the supported scope below. Reuse figi-validate@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 figi-validate@1.0.0 for validate a figi. 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

• validate a figi
• check figi check digit
• is this figi valid
• figi checksum validator
• parse figi provider prefix
• verify bloomberg global identifier
• which prefixes are banned in a figi

Not supported

• looking up which instrument a FIGI actually identifies
• validating a CUSIP (a different 8-character byte-level Double Add Double, see cusip-validate)
• accepting vowels anywhere in the FIGI body

Behavior

• figi must be exactly 12 characters: no case folding, no trimming. Any other length is reason wrong_length, checked first.
• prefix (characters 1-2) and check_digit (character 12) are the raw positional substrings whenever figi is exactly 12 characters, regardless of charset, forbidden-prefix or check-digit validity; both are null only when length already failed.
• Position 3 must be exactly "G". Characters 1-2 must each be an uppercase consonant (never a vowel, never a digit). Characters 4-11 must each be a digit or an uppercase consonant. Character 12 must be a digit, else reason invalid_character.
• prefix must not be one of BS, BM, GG, GB, GH, KY, VG (reserved to avoid confusion with country codes), else reason forbidden_prefix, checked once charset passes.
• Check digit (Modulus 10 Double Add Double over characters 1-11): a digit is itself, a letter is 10-35; double the value at even 1-based positions (2,4,6,8,10); reduce by summing its own two digits; sum the 11 results; expected check digit is (10 - sum mod 10) mod 10. A mismatch is reason check_digit_mismatch.
• valid is true only when length, charset, the forbidden-prefix rule and the check digit all pass, in that order; only one reason is ever returned.

Input

• figi (string, required): min length 1; max length 12

Output

• valid (boolean, required)
• reason (one of null, "wrong_length", "invalid_character", "forbidden_prefix", "check_digit_mismatch", required)
• prefix (string or null, required): min length 2; max length 2
• check_digit (string or null, required): min length 1; max length 1

Limits

• max figi bytes: 12

Example

Request input:

{
  "figi": "BBG000BLNNH6"
}

Response:

{
  "result": {
    "valid": true,
    "reason": null,
    "prefix": "BB",
    "check_digit": "6"
  }
}

How to call it

MCP

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

{
  "id": "figi-validate",
  "version": "1.0.0",
  "input": {
    "figi": "BBG000BLNNH6"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/figi-validate/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"figi":"BBG000BLNNH6"}'

The machine-readable contract is at /v1/tools/figi-validate/versions/1.0.0.

CLI

node cli.mjs run figi-validate 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• 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.
• Lei validate: Validate a 20-character LEI's ISO/IEC 7064 MOD 97-10 check digits and parse its LOU prefix and entity part.
• Isin validate: Validate a 12-character ISIN's ISO 6166 Luhn check digit and parse its country prefix, NSIN and NSIN scheme.
• Orcid validate: Validate a 16-digit ORCID iD or ISNI's ISO 7064 MOD 11-2 check character, accepting bare, grouped or URL forms.
• Sedol validate: Validate a 7-character SEDOL's weighted modulus 10 check digit and report whether it is a legacy all-numeric code.
• Cas number validate: Validate a CAS Registry Number's position-weighted mod 10 check digit over its variable-length first segment.