Check how
a text reads
A check reads a text with our AI detector and reports how likely it is to be AI-written, which paragraphs carry that, and the writing signals behind it. Checks run in the background, like runs. Each one is charged a small fixed price, held when it starts.
On this page
Starts a check and returns 202 Accepted. The API key needs the detect scope (see Authentication); without it the response is 403 insufficient_scope. Limited to 10 requests per minute per key.
curl https://humanizeword.com/api/v1/detections \
-H "Authorization: Bearer $HUMANIZEWORD_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"text": "Your text, in plain text or Markdown."
}'| Field | Description |
|---|---|
text | Required. Plain text or Markdown. Longer than restrictions.max_chars_per_run from GET /v1/me returns 400 text_too_long; text with no prose returns 400 no_prose. |
{
"id": "detection_01J9ABCDEF",
"status": "queued",
"words": 68,
"created_at": "2026-10-13T09:30:00+00:00",
"price_usd": "0.010000",
"charged_usd": null,
"result": null,
"error": null,
"progress": null,
"poll_url": "/api/v1/detections/detection_01J9ABCDEF"
}price_usd is held from your balance until the check finishes. If the available balance cannot cover it, the response is 402 insufficient_balance and nothing is queued. words counts prose only: Markdown structure and code are not charged.
Check statuses
| Status | Meaning |
|---|---|
queued | Waiting for the detector. |
running | Being read. progress shows the current stage. |
succeeded | result holds the report. charged_usd is the price, or 0.000000 when the text was too short to read. |
failed | error says why. Nothing is charged; the hold is released. |
Returns the check. Poll poll_url about once a second until status is succeeded or failed; most checks take a few seconds, a long text up to a minute. A check is kept for one hour after it was created and then returns 404, as does a check made by another account. The text you sent is never stored.
{
"id": "detection_01J9ABCDEF",
"status": "succeeded",
"words": 68,
"price_usd": "0.010000",
"charged_usd": "0.010000",
"result": {
"version": 1,
"score": 0.98,
"verdict": "ai",
"words": 68,
"sentences": 4,
"mean_sentence_words": 17.0,
"paragraphs": [
{"start": 0, "end": 286, "words": 35, "score": 0.98, "verdict": "ai"},
{"start": 288, "end": 556, "words": 33, "score": 0.98, "verdict": "ai"}
],
"signals": [
{
"key": "function_words",
"label": "Function-word density",
"value": 0.25,
"unit": "share",
"human": 0.5369,
"ai": 0.4625,
"lean": "ai",
"human_percentile": 1.0,
"reliability": 0.692,
"evidence": [{"start": 0, "end": 162}, {"start": 407, "end": 556}]
}
],
"models": 3,
"elapsed_ms": 4220
},
"error": null,
"progress": null,
"poll_url": "/api/v1/detections/detection_01J9ABCDEF"
}The report
Every start and end is a character offset into the exact text you sent, so you can highlight paragraphs and evidence in your own copy. Keep that copy: the report holds no text.
| Field | Description |
|---|---|
score | How likely the whole text is to be AI-written, from 0 to 1. |
verdict | human below 0.35, ai at 0.65 or above, mixed between. insufficient when the text has fewer than 40 words, which is not charged. |
paragraphs | Each paragraph's span, word count, score and verdict. A paragraph under 20 words has score and verdict null. |
signals | Writing signals that separate human from AI text on our measured corpus: this text's value, the typical human and AI values, which way it leans, how reliable the signal is (0–1), and evidence spans. |
models | How many classifiers read the text. |
Every detector, ours included, can be wrong about a given text, and other detectors will score the same text differently. Use the score as one signal, not as a verdict about who wrote something.
Returns what a check of this text would hold and charge now, without starting one. No API key is needed.
{
"text": "Remote work has fundamentally transformed the modern workplace."
}{
"prose_word_count": 8,
"price_usd": "0.010000"
}Pricing
A check is paid from the same balance as runs. Its price depends only on length, so it is known before you start: currently $0.01 per check up to about 5,000 words, then $0.002 per 1,000 words. POST /v1/detections/estimate always returns the current price. You are charged only when a reading lands: a check that fails, or a text too short to read, is not charged.
Limits
| Limit | Details |
|---|---|
| Rate | 10 checks per minute per key. A 429 includes a Retry-After header. |
| Length | Up to restrictions.max_chars_per_run characters (35,000 by default). At least 40 words for a verdict. |
| Retention | A check and its report are kept for one hour. The text is never stored. |