flemming-it 734d8f6e6f feat: text.anonymize v0.1.0 — regex-based PII redaction

First release. Pure-Rust, in-WASM, regex-only, declares no
permissions. Suitable as a first redaction pass after
text.extract before any cloud-LLM step.

Detection categories:

  EMAIL          RFC-5321-ish local@domain, IDN-aware.
  PHONE          International (+CC …) and DE national
                 (030 …, 0151-…) shapes, 7..20 raw digits.
  IBAN           Word-bounded [A-Z]{2}\d{2}[A-Z0-9]{11,30}.
                 Structural only — MOD-97 checksum
                 deliberately skipped so partial / truncated
                 tokens in running text still get redacted.
  BIC            8 or 11 uppercase alnum.
  IPV4           Four 0..255 octets, dot-separated.
  GERMAN_TAX_ID  11 consecutive digits, word-bounded.
  CUSTOM         Operator-supplied bare terms from the
                 newline-separated `custom_terms` input,
                 matched whole-word case-insensitive.

Token shape: ⟦TYPE_N⟧ — U+27E6 / U+27E7 mathematical white
square brackets. Distinct from any plain ASCII `[…]` already
present in source text (Markdown links, legal citations,
code blocks) so a reviewer never has to guess which `[…]`
is a redaction.

Outputs:

  anonymized  text  Input with PII replaced by ⟦TYPE_N⟧.
                    Counter restarts at 1 per type so the
                    tokens stay operator-readable.
  report      json  { redactions: [{type, token, original,
                    offset}…], counts: { TYPE: n, … } }.
                    Full original-text reconstruction is
                    possible from this — the GDPR
                    Art. 32(1)(a) "ability to undo"
                    requirement.

Quality bar (7 unit tests):
  * email round-trip
  * IBAN + BIC don't eat each other
  * three phone-number shapes redact
  * IPv4 only matches valid 0..255 octets
  * custom_terms case-insensitive
  * no double-redaction on overlapping patterns
  * per-category counter resets correctly

Built artefact: target/wasm32-wasip2/release/text_anonymize.wasm
(~180 KiB stripped).

NER for free-text names / organisations / locations is the
v0.2.0 plan once a benchmarked ONNX model is selected; the
operator's `custom_terms` field is the v0.1.0 escape hatch.

Signed-off-by: flemming-it <sf@flemming.it>

2026-05-25 20:53:24 +02:00

2.8 KiB

Raw Blame History

text.anonymize

Regex-based PII anonymization for plain text. Detects and replaces personally-identifiable patterns with stable tokens of the shape ⟦TYPE_N⟧, and emits a JSON report describing every redaction so a downstream verify step can audit completeness.

Capability

text.anonymize@0.1.0

Inputs

Name	Type	Description
`text`	text	UTF-8 string to redact.
`custom_terms`	text	Optional. Newline-separated list of extra bare terms to redact whole-word (case-insensitive).

Outputs

Name	Type	Description
`anonymized`	text	The input text with PII replaced by `⟦TYPE_N⟧` tokens.
`report`	json	`{ redactions: [{ type, token, original, offset }…], counts: { TYPE: n, … } }`.

Categories detected

Type	Pattern
`EMAIL`	RFC-5321-ish `local@domain`, IDN domains OK.
`PHONE`	International (`+49 …`) or German national (`030 …`, `0151-…`) shape.
`IBAN`	Word-bounded `[A-Z]{2}\d{2}[A-Z0-9]{11,30}`. Structural only — checksum deliberately not computed.
`BIC`	Word-bounded uppercase alnum, 8 or 11 chars.
`IPV4`	Four 0..255 octets, dot-separated.
`GERMAN_TAX_ID`	11 consecutive digits, word-bounded.
`CUSTOM`	Every line of `custom_terms` matched whole-word, case-insensitive.

No NER yet. v0.2.0 will add a small ONNX model for name / organisation detection once we have a benchmarked candidate.

Permissions

None. Pure-Rust, regex-only, in-WASM. No filesystem, no network, no LLM call.

Example flow

name: redact-case-file
inputs:
  document: bytes
steps:
  - id: extract
    use: text.extract@^0
    with:
      document: $inputs.document
  - id: redact
    use: text.anonymize@^0
    with:
      text: $extract.extracted.pages[*].text
      custom_terms: |
        Mustermann
        Musterfrau
outputs:
  redacted: $redact.anonymized
  audit_report: $redact.report

Build

cargo build --release --target wasm32-wasip2
# Output: target/wasm32-wasip2/release/text_anonymize.wasm

2.8 KiB Raw Blame History