A Cobra CLI to transform various personal finance file types (GnuCash, Ledger format, credit card statement CSV files)
You can run subcommands within the main.go file to convert GnuCash's uncompressed XML file to a
Ledger journal. This script was originally written using Perl, but maintaining Perl dependencies is
neither fun nor something that I am interested in anymore. So, the script has been re-written to
Golang; primarily using AI.1
The file formats for ledger and hledger are nearly identical. So, the output from this
script can be used with either program.
# Decompress the GnuCash file and write to an input XML file
zcat input.gnucash > input.xml
# Use this script to convert the input into a Ledger file
go run main.go gnucash-to-ledger input.xml output.dat
# Confirm that the output is valid
hledger -f output.dat bal$ cat ./TestData/TestBook-Prestia/202509.csv ./TestData/TestBook-Prestia/202510.csv | go run main.go prestia-to-ledger - | head -10
2026/06/12 12:40:25 WARN invalid line in Prestia statement > number of fields mismatch, want 7 num_fields=3 fields="[ジョナサン\u3000太郎\u3000様 1234-00**-****-**** プレスティアＶｉｓａゴールド]"
2026/06/12 12:40:25 WARN invalid line in Prestia statement > number of fields mismatch, want 7 num_fields=3 fields="[エリザベス\u3000太郎\u3000様 1235-11**-****-**** ＧｏｏｇｌｅＰａｙ／ｉＤ]"
2026/06/12 12:40:25 WARN invalid line in Prestia statement > first field is not a date in YYYY/MM/DD format first_field="" parse_error="parsing time \"\" as \"2006/01/02\": cannot parse \"\" as \"2006\""
2026/06/12 12:40:25 WARN invalid line in Prestia statement > number of fields mismatch, want 7 num_fields=3 fields="[ジョナサン\u3000太郎\u3000様 1234-00**-****-**** プレスティアＶｉｓａゴールド]"
2026/06/12 12:40:25 WARN invalid line in Prestia statement > number of fields mismatch, want 7 num_fields=3 fields="[エリザベス\u3000太郎\u3000様 1235-11**-****-**** ＧｏｏｇｌｅＰａｙ／ｉＤ]"
2026/06/12 12:40:25 WARN invalid line in Prestia statement > first field is not a date in YYYY/MM/DD format first_field="" parse_error="parsing time \"\" as \"2006/01/02\": cannot parse \"\" as \"2006\""
2025-08-20 飲食店
Liabilities:Prestia Card "JPY" -600
Expenses
2025-08-25 飲食店
Liabilities:Prestia Card "JPY" -750
Expenses
2025-09-04 飲食店
Liabilities:Prestia Card "JPY" -900
This command prints an error if the two registers have transactions in different currencies, or if each register has transactions in more than one currency:
$ go run main.go diff-ledger register \
<(dock_hledger -f ./TestData/TestBook-Prestia/prestia-statement-jpy.dat register --begin 2025-08 --end 2025-08-31 'Liabilities' -O csv | head -n10) \
<(dock_hledger -f ./TestData/TestBook-Ledger/TestBook.ledger.dat register --begin 2025-08-01 --end 2025-08-31 'Liabilities' -O csv | head -n10)
Error: currency mismatch between file 1 and file 2: file 1 currency: JPY, file 2 currency: INR
Usage:
personal-finance-transformer diff-ledger register <csv-file-1> <csv-file-2> [flags]
Flags:
-h, --help help for register
exit status 1
The command will print the diff between two Ledger registers which were printed as CSV:
$ go run main.go diff-ledger register \
<(dock_hledger -f ./TestData/TestBook-Prestia/prestia-statement-inr.dat register --begin 2025-08 --end 2025-08-31 'Liabilities' -O csv | head -n10) \
<(dock_hledger -f ./TestData/TestBook-Ledger/TestBook.ledger.dat register --begin 2025-08-01 --end 2025-08-31 'Liabilities' -O csv | head -n10)
Parsed 3 transactions from /proc/self/fd/11
Parsed 6 transactions from /proc/self/fd/12
=== Transactions in File 1 but not in File 2 === Count: 0
=== Transactions in File 2 but not in File 1 === Count: 3
2025-08-02 | INR -3500 | Liabilities:Credit Card | Groceries
2025-08-20 | INR -750 | Liabilities:Credit Card | Electricity
2025-08-25 | INR -800 | Liabilities:Credit Card | T-shirts
There is also a way to present the transaction diffs as a TSV file. This makes it easier to see the monthly diff in a Spreadsheet tool:
$ go run main.go diff-ledger register \
<(dock_hledger -f ./TestData/TestBook-Prestia/prestia-statement-inr.dat register --begin 2025-10-01 --end 2025-10-31 'Liabilities' -O csv | head -n10) \ <(dock_hledger -f ./TestData/TestBook-Ledger/TestBook.ledger.dat register --begin 2025-10-01 --end 2025-10-31 'Liabilities' -O csv | head -n10) | sed '1,/=== Output as TSV/ d'
2025-10-26 INR -410 Liabilities:Credit Card 海外飲食店 2025-10-07 INR -250 Liabilities:Credit Card Lunch
2025-10-10 INR -1380 Liabilities:Credit Card Groceries
2025-10-19 INR -2000 Liabilities:Credit Card Groceries
2025-10-20 INR -400 Liabilities:Credit Card Electricity
2025-10-25 INR -400 Liabilities:Credit Card Dinner
2025-10-26 INR -400 Liabilities:Credit Card Dinner Abroad
2025-10-28 INR -1900 Liabilities:Credit Card T-shirts
The TSV output is hard to read in the terminal. It is easier to see the value of this output format in a Spreadsheet application:
When making changes to the script, confirm that the changes that are made in the TestData are logical.
# Convert "./TestData/TestBook-GnuCash/TestBook.gnucash" into a Ledger file
# using the converter script
$ zcat TestData/TestBook-GnuCash/TestBook.gnucash | go run main.go gnucash-to-ledger - > /tmp/converted.dat
# Confirm that actual and expected are identical
$ diff ./TestData/TestBook-Ledger/TestBook.ledger.dat /tmp/converted.dat
# Oneliner:
$ diff TestData/TestBook-Ledger/TestBook.ledger.dat <(zcat TestData/TestBook-GnuCash/TestBook.gnucash | go run main.go gnucash-to-ledger -)
These oneliners will run Ledger with a read-only file system connected to the current working directory. The read-only file system ensures that the container can not change any of the files that are in the current working directory. This might be useful to you if you store the GnuCash and Ledger files in the same directory.
hledger () {
docker run --rm --volume $(pwd):/data:ro -w /data dastapov/hledger hledger $@
}
ledger () {
docker run --rm --volume $(pwd):/data:ro -w /data dcycle/ledger:1 $@
}Commodity directives can be used to ensure that numbers are always displayed in the appropriate format.
$ cat commodities.dat
commodity JPY 1,000,000.
commodity EUR 1,000,000.00
commodity USD 1,000,000.00
commodity INR 10,00,000.
; Enter the appropriate exchange rate for the various commodities here
P 2020-02-08 EUR 0.001 USD
hledger -f simple.dat incomestatement
hledger -f simple.dat balancesheet
hledger -f simple.dat cashflow# You _must_ have the exchange rate in USD for all the commodities in the
# commodities.dat file
hledger -f simple.dat bal Assets -Y --value=now,USDCode in this repository is licensed under MIT.
Copyright (C) 2020 Siddharth Kannan mail@siddharthkannan.in
Footnotes
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OpenCode with Claude Sonnet 4.5 ↩