confusable-unicode-audit

namespace	aiwg
name	confusable-unicode-audit
platforms	["all"]
description	Detect bidi controls, zero-width characters, mixed-script identifiers, and homoglyph risks in source and release metadata
requires	[{"git":"repository file enumeration"}]
ensures	[{"report":"suspicious Unicode occurrences with code point, context, and allowlist status"},{"exit-code":"non-zero when violations found and --fail-on-violation is set"}]
errors	[{"allowlist-invalid":".aiwg/security/confusable-unicode-allowlist.yaml cannot be parsed"}]
invariants	["exact code points are reported so reviewers do not need visual inspection","allowlisted non-ASCII is still included in the exceptions section"]
commandHint	{"argumentHint":"[--fail-on-violation] [--include-metadata] [--format text|json]","allowedTools":"Read, Bash, Grep","model":"haiku","category":"security","orchestration":false,"modelRole":"efficiency","modelTier":"economy"}

Confusable Unicode Audit

Detect Trojan Source and homoglyph risks in source files, dependency names, and release metadata. This enforces no-confusable-unicode and maps curl Practice 8 into an AIWG control.

Detection Targets

• Bidirectional controls: U+202A through U+202E, U+2066 through U+2069.
• Zero-width characters: U+200B through U+200F, U+FEFF.
• Non-ASCII identifiers in source code.
• Mixed-script identifiers, especially Latin plus Cyrillic or Greek.
• Package/dependency names containing non-ASCII or confusable characters.
• Optional metadata scan: commit subject, PR titles, release notes.

Allowlist

Legitimate non-ASCII is declared in .aiwg/security/confusable-unicode-allowlist.yaml:

version: 1
allow:
  - path: "docs/i18n/**"
    reason: "localized documentation"
  - identifier: "naive_bayes"
    codepoints: ["U+00EF"]
    reason: "historical exported API spelling"

Output

Reports show file, line, column, Unicode code point, character name, and remediation. Bidi and zero-width controls are always HIGH severity.

References

• agentic/code/frameworks/security-engineering/rules/no-confusable-unicode.md
• Unicode TR39
• Trojan Source / CVE-2021-42574