Docs · Validators

`npi` validator

US National Provider Identifier — 10 digits, Luhn check on `80840` prefix.

One of 19 validator types · pure compute, no AI cost

Reference

Format

Matches `/^\d{10}$/`, then runs the CMS-specified Luhn check: compute Luhn on `"80840" + value.slice(0, 9)`, then the trailing digit of `value` must be the Luhn check digit.

Examples

1234567893
1003000126
1467560003

How it runs

Implementation

A faithful summary of lib/validators.ts. Validators are pure functions and run identically in the Worker, the Workbench and the MCP server — one implementation, so the three cannot disagree about whether a value is valid.

lib/validators.ts

function validNpi(value) {
  if (!/^\d{10}$/.test(value)) return fail('npi_format', 'expected 10 digits')
  const target = ('80840' + value.slice(0, 9)).split('').map(Number)
  let sum = 0
  for (let i = target.length - 1; i >= 0; i--) {
    let d = target[i]
    if ((target.length - i) % 2 === 1) { d *= 2; if (d > 9) d -= 9 }
    sum += d
  }
  return (sum + Number(value[9])) % 10 === 0
    ? OK
    : fail('npi_checksum', 'NPI Luhn check failed')
}

Config

Use in a template

Validators attach to a field on a custom template. The cascade runs them after mapping but before commit; failures surface in the per-row validation report.

template.yaml

fields:
  - column: npi
    type: string
    validators:
      - type: npi

Watch out

Common gotchas

The `80840` prefix is per CMS NPI specification — do NOT pass an 80840-prefixed string in; pass the bare 10-digit NPI.
Type 1 (individual) and Type 2 (organisation) NPIs use the same checksum — we do not infer or check the entity type.
NPPES registry lookup is not performed. A syntactically valid NPI may be deactivated.

Where it runs

Three routes, no AI cost.

POST/v1/validate-rowValidate one row against a template. Stateless, no key, pure compute — the fastest way to try npi against a real value.no key
POST/v1/uploads/:id/validateRun every field validator over the parsed upload, without committing. Returns errors and warnings per row.read
POST/v1/uploads/:id/commitValidates on the way out. skip_invalid_rows drops the failures instead of failing the commit.commit

Validators are pure functions, so they add nothing to the AI bill. Every map draws a small flat per-map fee from your prepaid token wallet ($10 minimum, shared across the phi-cloud suite); only columns that reach the metered LLM layer, plus any-to-any convert and structural reshape, bill real AI tokens. See pricing

Catalogue

Related templates

Provider directoryprovider_directory_v1
Providers with NPI/GLN/license metadata.
Fields · npi

Explore

All 19 validator types

The complete list a template field can declare. There is no SNOMED validator — it required an affiliate licence, no template used it, and it was removed in 2026.

Back to the documentation index or browse the template catalogue.

Ready when you are

Validate every row — before it lands.

Attach checksum-strict validators to any field, and gate risky commits behind the requires_hitl flag. One key runs the whole cascade.

Get an API key See pricing

Prepaid token wallet · schema-only data-minimization mode · no free tier

npi validator