# Paraphrases

Rewrite academic text with control over tone, length, and how far the wording may drift.

## Endpoints

| Method | Path | Scope | Credits | Description |
|---|---|---|---|---|
| POST | `/v1/paraphrases` | `paraphrases:write` | 1 per 500 words | Rewrite text |

## Parameters

| Parameter | Type | Required | Description |
|---|---|---|---|
| `text` | string | yes | Input text, up to 5,000 words |
| `tone` | enum | no | `academic` (default), `fluent`, `formal`, `plain`, `concise`, `persuasive` |
| `length` | enum | no | `shorten`, `preserve` (default), `expand` |
| `variation` | enum | no | `low`, `medium` (default), `high` — how far wording may drift |
| `language` | string | no | Output language; omit to preserve input language |
| `variants` | integer | no | How many alternatives to return, default 1 |

> [!info] Fewer tones than the web app
> The consumer product exposes 20+ tones including `sarcastic` and `passive-aggressive`. The API ships
> the six with an academic use case. If you need one of the others, tell us why at
> `api-feedback@scispace.com`.

Cost is 1 credit per 500 words of input, per variant.

## Response

```json
{
  "object": "paraphrase",
  "id": "para_19jx1ybv5x",
  "tone": "academic",
  "length": "preserve",
  "variation": "medium",
  "language": "en",
  "variants": [
    {
      "text": "Climate change is causing measurable reductions in species richness across terrestrial ecosystems.",
      "sentences": [
        {
          "index": 0,
          "text": "Climate change is causing measurable reductions in species richness across terrestrial ecosystems.",
          "source_index": 0
        }
      ]
    }
  ]
}
```

`sentences[].source_index` maps each rewritten sentence to the input sentence it came from, so callers
can diff or re-splice. Citations in the input are preserved verbatim.

## Errors

| Status | `code` | When |
|---|---|---|
| 400 | `text_too_long` | over the input cap |
| 422 | `language_unsupported` | see chats language notes |

## Related

ai-detections · credit