Finance as Code Budget

Finance as Code is a personal finance automation project that moves transactions from different inputs into budgeting destinations in a repeatable, code-driven way.

Goal: define your data flow once, then run it reliably to keep your tools in sync.

Sources are where transactions come from (for example bank CSV exports or online APIs). Sinks are where normalized transactions are written (for example local apps or external services).

Supported sources and sinks

Affiliate disclosure: links to Lunch Flow and Lunch Money may be affiliate links. If you use them, I may earn a commission at no extra cost to you.

Sources

Banks

Source	Feature	Supported
mBank CSV	source_mbank	Yes

Online Services

Source	Feature	Supported
Lunch Flow	source_lunchflow	Yes

Sinks

Local Applications

Sink	Feature	Supported
Treeline	sink_treeline	Yes

Services

Sink	Feature	Supported
Lunch Money	sink_lunchmoney	Yes

Notes:

• For Lunch Flow, use the downloader as a setup (run before sources) to download files, then use LocalDirectorySource to read them.
• all enables all source/sink features.
• all_with_db enables all source/sink features and bundled_db for Treeline.

Quick start

This library is not published on crates.io yet. Add it from GitHub with the feature set you need:

[dependencies]
finance_as_code_budget = { git = "https://github.com/andrzejressel/finance-as-code.git", features = ["all_with_db"] }

all_with_db enables all sources/sinks and bundles DuckDB for Treeline. If you have a weaker PC you can try using all instead which uses prebuilt duckdb:

[dependencies]
finance_as_code_budget = { git = "https://github.com/andrzejressel/finance-as-code.git", features = ["all"] }

In that case however you must set DUCKDB_DOWNLOAD_LIB="1" in your environment variables to allow downloading the duckdb library. You can automate it by creating .cargo/config.toml with the following content:

[env]
DUCKDB_DOWNLOAD_LIB = "1"

Quick start usage: Lunch Flow -> Lunch Money

use finance_as_code_budget::{
    LocalDirectorySource, Setup, Sink, Source,
    lunchflow::{
        LunchFlowDownloaderConfig, create_lunchflow_downloader, create_lunchflow_file_reader,
    },
    lunchmoney::{LunchMoneySinkConfig, create_lunchmoney_sink},
    run,
};

fn main() {
    let lunchflow_dir = "path/to/lunchflow/dir";

    let setups: Vec<Box<dyn Setup>> = vec![
        Box::new(create_lunchflow_downloader(
            LunchFlowDownloaderConfig::builder()
                .account_id(123_i64)
                .api_key("lunchflow_api_key")
                .local_directory(lunchflow_dir)
                .build(),
        )
        .expect("Failed to create Lunch Flow downloader")),
    ];

    let sources: Vec<Box<dyn Source>> = vec![
        Box::new(LocalDirectorySource::new(
            lunchflow_dir,
            create_lunchflow_file_reader(),
        )
        .expect("Failed to create local directory source")),
    ];

    let sinks: Vec<Box<dyn Sink>> = vec![Box::new(create_lunchmoney_sink(
        LunchMoneySinkConfig::builder()
            .api_key("lunchmoney_api_key")
            .account_name("My Account")
            .build(),
    ))];

    run(setups, sources, vec![], sinks).expect("Pipeline run failed");
}

Quick start usage: Lunch Flow -> Treeline

use finance_as_code_budget::{
    LocalDirectorySource, Setup, Sink, Source,
    lunchflow::{
        LunchFlowDownloaderConfig, create_lunchflow_downloader, create_lunchflow_file_reader,
    },
    treeline::{SinkTreelineOptions, create_treeline_sink},
    run,
};

fn main() {
    let lunchflow_dir = "path/to/lunchflow/dir";

    let setups: Vec<Box<dyn Setup>> = vec![
        Box::new(create_lunchflow_downloader(
            LunchFlowDownloaderConfig::builder()
                .account_id(123_i64)
                .api_key("lunchflow_api_key")
                .local_directory(lunchflow_dir)
                .build(),
        )
        .expect("Failed to create Lunch Flow downloader")),
    ];

    let sources: Vec<Box<dyn Source>> = vec![
        Box::new(LocalDirectorySource::new(
            lunchflow_dir,
            create_lunchflow_file_reader(),
        )
        .expect("Failed to create local directory source")),
    ];

    let sinks: Vec<Box<dyn Sink>> = vec![Box::new(create_treeline_sink(
        SinkTreelineOptions::builder()
            .account_name("My Treeline Account")
            .build(),
    ))];

    run(setups, sources, vec![], sinks).expect("Pipeline run failed");
}

The Treeline sink performs a full replacement for the selected account (existing transactions and balances for that account are removed before import).

How LocalDirectorySource works

LocalDirectorySource is the file-based source in the pipeline. You point it to a folder and provide a matching file reader, and it imports supported transaction files from that folder.

• Use create_mbank_file_reader() for mBank CSV exports.
• Use create_lunchflow_file_reader() for Lunch Flow JSON files.
• In Lunch Flow flows, run the downloader as a setup first so it saves files locally, then use LocalDirectorySource to import them.