CFONB

A parser for CFONB bank files — the French banking interchange standard (Comité Français d'Organisation et de Normalisation Bancaires).

This first version parses the 120-character account statement (relevé de compte): previous balance (01), operations (04), operation details (05), and new balance (07). Amounts are returned as Decimal so money is never represented as a float.

Installation

def deps do
  [
    {:cfonb, "~> 0.1.0"}
  ]
end

Usage

{:ok, statements} = CFONB.parse(File.read!("releve.txt"))

[statement | _] = statements
statement.account       #=> "98765432100"
statement.from_balance  #=> #Decimal<-190.40>
statement.to_balance    #=> #Decimal<-241.21>

[operation | _] = statement.operations
operation.label                    #=> "PRLV SEPA TEST CABINET"
operation.amount                   #=> #Decimal<-32.21>
operation.details.operation_reference #=> "REFERENCE"
operation.details.debtor           #=> "INTERNET SFR"
operation.details.fee              #=> #Decimal<0.79>  (when a FEE detail is present)

The 05 detail records are decoded into a CFONB.Operation.Details struct (qualifiers such as LIB, REF, RCN, NPY, FEE, MMO, …). Unrecognized qualifiers are preserved under details.unknown.

The library also derives banking identifiers and exposes the raw records:

CFONB.Statement.rib(statement)          #=> "20041010050500013M02606"
CFONB.Statement.iban(statement)         #=> "FR1420041010050500013M02606"
CFONB.Operation.type_code(operation)    #=> "B1D"  (interbank code + credit/debit)
statement.begin_raw                     #=> the original "01" line
CFONB.Statement.raw(statement)          #=> the statement's records, rebuilt

Other entry points:

CFONB.parse_operation(input)      # parse a standalone 04 (+ its 05s)
CFONB.parse(input, optimistic: true)   # skip invalid records, best effort
CFONB.parse!(input)               # raising variants

CFONB.parse/1 returns {:ok, [%CFONB.Statement{}]} or {:error, reason}. Use CFONB.parse!/1 if you prefer raising on invalid input.

See FORMAT.md for the exact CFONB 120 field layout.

Scope & roadmap

• v0.1 — CFONB 120 account statement (all record types), qualifier-specific 05 decoding, RIB/IBAN derivation, raw-record access, standalone-operation and optimistic parsing. At feature parity with the reference Ruby gem.
• Planned — the 240-character format, and CFONB generation (e.g. transfer orders).

Credits & license

Reimplemented from the official CFONB specification, with a data model inspired by and compatible with the Ruby gem pennylane-hq/cfonb (MIT) — its test files are reused as a parsing oracle. Released under the MIT license.