The classifier.dev CLI. Sort text into your own labels from the shell — up to a thousand lines per request, a calibrated confidence on every answer, no API key.

npm i -g classifier-dev        # installs `classify`
npx classifier-dev --help      # or run it without installing

Use

classify spam,"not spam" "Win a free iPhone now"
spam

classify bug,feature,praise < feedback.txt
bug       0.99    the checkout button does nothing
praise    0.97    love the new dark mode
feature   0.61    would be nice to export as CSV

One line per input, in input order: label, confidence, text, tab-separated (--id adds the id between confidence and text). --json gives NDJSON with everything the API returns; --quiet gives labels only; --count gives a histogram.

Built for agents

The confidence is calibrated (on a six-way emotion set, answers at ≥ 0.9 were right 82% of the time; below 0.5, 29%), so the useful move is to trust the sure ones and look at the rest yourself:

classify relevant,"not relevant" -i "relevant means about GPU pricing" --review 0.7 < snippets.txt

prints only the inputs the model was unsure about. Or let the API do it: --smart re-asks those of a reasoning model.

Input can be plain lines, a JSON array, or NDJSON; --field picks the text field and --id carries an id through:

cat issues.jsonl | classify bug,question,feature --field title --id number --json

10,000 lines are batched 1,000 per request, four at a time, and a rate limit pauses and resumes rather than failing. Errors go to stderr with exit code 1.

Options

-m, --multi                every label that applies, plus a score per label
-k, --max <n>              at most n labels (implies --multi)
-s, --smart                re-ask uncertain answers of a reasoning model
-i, --instructions <text>  extra criteria
-r, --review <t>           print only inputs with confidence below t
-c, --count                label histogram instead of rows
-j, --json                 NDJSON output
-q, --quiet                labels only
    --field <name>         text field for JSON / NDJSON input (default: text)
    --id <name>            id field to carry through
    --endpoint <url>       API base (env CLASSIFY_ENDPOINT)
    --api-key <key>        bearer token for higher limits (env CLASSIFY_API_KEY)

classify --help has examples. Environment: CLASSIFY_TIMEOUT (seconds per request, default 180), CLASSIFY_NO_PROGRESS, and CLASSIFY_NO_UPDATE_CHECK=1 to skip the once-a-day version check.

What it refuses to do quietly

An answer from the API that is short, empty, or in the wrong shape stops the run with exit 1 rather than printing fewer rows. Every retry — rate limit, upstream error, network — is announced on stderr, and a timed-out request is retried once, not five times. With --smart, answers the reasoning model could not re-ask are counted on stderr, so a degraded smart tier never looks like a normal one.

Versioning

Semver. classify --version prints it; the CLI mentions a newer release on stderr once a day. Changes are in CHANGELOG.md; releases are cut with npm run release (see release.js) and published from the cli-v* tag.