simplelocalize-download 0.1.0

Resilient Rust-powered port of the SimpleLocalize CLI download command, with a Python library and Typer CLI.

simplelocalize-download

A resilient, Rust-powered port of the SimpleLocalize CLI download command, shipped as a Python package with a Typer CLI.

Scope by design: the download command, JSON only (single-language-json). The core is written in Rust (tokio + reqwest) for concurrent, retrying, atomic downloads and exposed to Python via PyO3 / maturin. No JVM required.

Why

The Java CLI downloads files sequentially with no retries — a single transient hiccup aborts the run. This port moves resilience into the tool: bounded concurrency, exponential backoff with jitter, and atomic writes, so a flaky API doesn't fail your pipeline. It also drops the JVM: a uvx simplelocalize-download one-liner replaces downloading a JAR, verifying its checksum, and running java -jar.

Install

uvx simplelocalize-download --help      # run without installing
pipx install simplelocalize-download    # or install as a tool
pip install simplelocalize-download     # or into an environment

CLI usage

simplelocalize-download download \
  --api-key "$SIMPLELOCALIZE_API_KEY" \
  --download-path './json/{lang}/{ns}.json' \
  --download-options WRITE_NESTED \
  --download-sort LEXICOGRAPHICAL

The API key is read from --api-key or the SIMPLELOCALIZE_API_KEY environment variable.

Options

Option	Alias (Java CLI)	Notes
--api-key	--apiKey	Or SIMPLELOCALIZE_API_KEY. Required.
--download-path	--downloadPath	Required. Template with {lang}, {ns}, {customer}, {translationKey}, {remotePath}.
--download-format	--downloadFormat	Default single-language-json; anything else is rejected.
--download-options	--downloadOptions	Comma-separated, e.g. WRITE_NESTED.
--download-sort	--downloadSort	e.g. LEXICOGRAPHICAL.
--language-key	--downloadLanguageKey	Comma-separated language filter.
--namespace	--downloadNamespace	Namespace filter.
--tags	--downloadTags	Comma-separated tag filter.
--customer-id	--downloadCustomerId	Customer ID filter.
--base-url	--baseUrl	Default https://api.simplelocalize.io.
--concurrency	—	Max concurrent file downloads (default 8).
--timeout	—	Per-request timeout in seconds.
-v / -q	—	Verbose (debug) / quiet (warnings only) logging.
--no-progress	—	Disable the progress bar.

The Java CLI's camelCase flag spellings are accepted as aliases, so existing invocations port by swapping only the binary name.

Exit codes

Code	Meaning
0	Success.
2	Usage / validation error (missing API key, unsupported format).
3	Authentication failed (HTTP 401/403).
4	API or network error (pre-flight).
5	Some files failed to download (partial failure).

Library usage

import simplelocalize_download as sld

def on_event(event: dict) -> None:
    if event["type"] == "file_done":
        print("downloaded", event["path"])

try:
    report = sld.download(
        api_key="...",
        download_path="./json/{lang}/{ns}.json",
        download_options=["WRITE_NESTED"],
        download_sort="LEXICOGRAPHICAL",
        concurrency=8,
        on_event=on_event,
    )
    print(f"{len(report.downloaded)} files")
except sld.AuthError as err:
    print("bad credentials", err.status)
except sld.DownloadFailedError as err:
    for failed in err.report.failed:
        print("failed:", failed.url, failed.error)

Exceptions: SimpleLocalizeError (base) → AuthError (has .status), ApiError (has .status), NetworkError, and DownloadFailedError (has .report).

Resilience

• Concurrency: files download in parallel with a bounded limit (--concurrency, default 8).
• Retries: connect errors, timeouts, HTTP 429 and 5xx are retried with exponential backoff and full jitter, honoring Retry-After. Other 4xx fail fast.
• Atomic writes: each file streams to a temp file in the destination directory and is renamed into place, so a crash never leaves a half-written translation file.
• Partial-failure reporting: a failed file doesn't abort the batch; every file is attempted and failures are collected. The CLI exits non-zero (code 5) so CI still catches problems.

What's not supported

This port intentionally covers only the download command for JSON. Not supported:

• Other commands: upload, publish, auto-translate, pull, purge, extract, init.
• Non-JSON formats (YAML, Android, iOS, Java properties, …) — every format other than single-language-json.
• simplelocalize.yml config files (pass everything via flags / environment).

For those, use the upstream SimpleLocalize CLI.

Development

uv sync
uv run maturin develop
uv run pytest

See CONTRIBUTING.md.