📦 Rule Packs Reference

Applies to: FinLang v0.6+ Status: Stable Last verified: v0.7.9

Rule packs are pre-built .fin files that provide baseline categorization logic. They save you from writing common rules from scratch.

🚀 Quick Start

Include packs using the --include-pack flag:

# Single pack
finlang --input bank.csv --output out.csv --rules my_rules.fin --include-pack retail

# Multiple packs (comma-separated)
finlang --input bank.csv --output out.csv --rules my_rules.fin --include-pack retail,sanity,transport

🔹 How Packs Work

1. Your rules take precedence — Personal rules in --rules are applied first (highest priority).
2. Packs provide baseline coverage — They catch common patterns you haven't written rules for yet.
3. Last rule wins — If multiple rules match, the last one in execution order sets the category.
4. Flags accumulate — All matching rules contribute flags (space-separated).

Execution order:

Your rules (--rules) → Pack 1 → Pack 2 → Pack 3 ...

💡 Tip: Packs set category = "Review" by default. This is intentional — review the matches, then update your personal rules with the correct categories.

🔹 Bundled Packs (Free)

These packs ship with FinLang and are available immediately:

Pack Details

retail — UK Grocery & Retail

Matches major UK supermarkets and retail chains.

Patterns: *TESCO*, *SAINSBURY*, *LIDL*, *ALDI*, *ASDA*, *MARKS*SPENCER*, *M&S*, *CO*OP*, *ICELAND*

Sets: category = "Review", flags += "Retail"

transport — Transport & Fuel

Matches ride-sharing, public transport, and fuel stations.

Patterns: *UBER*, *TRAINLINE*, *TFL*, *SHELL*, *BP*, *NATIONAL*RAIL*

Sets: category = "Review", flags += "Transport" or flags += "Fuel"

subscriptions (alias: subs) — Streaming & Software

Matches common subscription services.

Patterns: *SPOTIFY*, *NETFLIX*, *AMAZON*PRIME*, *YOUTUBE*PREMIUM*, *APPLE.COM/BILL*, *MICROSOFT*, *ADOBE*

Sets: category = "Review", flags += "Subscription"

travel — Airlines & Accommodation

Matches travel booking platforms and airlines.

Patterns: *AIRBNB*, *BOOKING*COM*, *EASYJET*, *RYANAIR*, *BRITISH*AIRWAYS*, *HOTELS*COM*, *EXPEDIA*

Sets: category = "Review", flags += "Travel"

financial — Bank Fees & Interest

Matches bank operational charges.

Patterns: *BANK*CHARGE*, *INTEREST*, *FX*FEE*, *CASH*WITHDRAWAL*, *ATM*, *OVERDRAFT*

Sets: category = "Review", flags += "BankFee" / "Interest" / "FX" / "Cash"

compliance — Compliance Flags

Non-destructive flagging for audit/compliance workflows.

Logic:

• Large transactions (≥ £500 debit or credit) → flags += "LargeTxn"
• Non-sterling indicators → flags += "FX"
• Duplicate markers in memo → flags += "PotentialDuplicate"

Sets: Flags only (does not change category).

sanity — Data Quality Checks

Catches data issues that need manual review.

Logic:

• Empty counterparty → flags += "EmptyCounterparty"
• Zero amount → flags += "ZeroAmount"
• Memo contains "REFUND" → flags += "RefundCheck"

Sets: category = "Review", plus relevant flag.

examples — Tutorial & Learning

Demonstrates FinLang operators and syntax. Not for production use.

Covers: Equality (==), wildcards (~), amount ranges (in), flag appending (+=).

🔹 Commercial Packs

For complex use cases, FinLang Ltd offers commercial rule packs with deeper coverage.

Banking Pack v1.0 (£49)

92 rules for UK banking data normalization.

Key features:

• Neobank detection (Revolut, Wise, Monzo)
• UK payment rail decoding (BACS, FPS, CHAPS, BGC)
• Directional logic (distinguishes funding from spending)
• Sentinel tagging (Pack:Banking_v1.0)

See Commercial Rulepacks - Banking Pack (Banking Pack v1.0) for full details.

Purchase: finlang.io

🔹 Using Commercial Packs

Commercial packs are standalone .fin files. Include them via --rules:

# Your rules + commercial pack
finlang --input bank.csv --output out.csv \
  --rules my_rules.fin \
  --rules banking/Banking.ReconcileHeuristics.fin \
  --rules banking/Banking.BankFees.fin \
  --include-pack sanity

Or concatenate into a single file:

cat my_rules.fin banking/*.fin > combined_rules.fin
finlang --input bank.csv --output out.csv --rules combined_rules.fin

🔹 Best Practices

1. Start with retail,sanity — Good baseline for personal finance.
2. Review before trusting — Packs set category = "Review" intentionally.
3. Graduate rules to your personal file — Once verified, copy rules to my_rules.fin with correct categories.
4. Don't over-include — Only add packs relevant to your data.

Recommended combinations:

🔹 Creating Your Own Packs

Any .fin file can be a pack. To create a reusable pack:

1. Write rules following Rule Language syntax.
2. Use descriptive rule names with a prefix (e.g., "MyPack: Vendor Name").
3. Consider adding a sentinel flag: flags += "Pack:MyPack_v1.0".
4. Test thoroughly before sharing.

Example custom pack structure:

# MyCompany Vendor Pack v1.0

rule "MyPack: Preferred Supplier A" {
  match:
    - counterparty ~ "*SUPPLIER A*"
  set:
    - category = "Approved Vendors"
    - flags += "Pack:MyCompany_v1.0"
}

🔹 Cross-References

• CLI Reference — --include-pack flag details
• Rule Language — Writing custom rules
• Workflows — Using packs in daily runs
• Growth Loop Best Practices — Iterating on coverage

© FinLang Ltd