Overview
Originality.ai combines AI content detection with plagiarism checking in a single API. It uses a credit-based pricing model where each scan costs credits proportional to word count.
- API base URL:
https://api.originality.ai/api/v1 - Auth:
X-OAI-API-KEYheader - Docs: https://docs.originality.ai
Instructions
Authentication
Set ORIGINALITY_API_KEY in your environment. Pass it in the X-OAI-API-KEY header for all requests.
AI Detection — POST /api/v1/scan/ai
Send { "content": "<text>", "aiModelVersion": "1", "storeScan": false }. Returns:
score.ai(0-1) — probability of AI authorshipscore.original(0-1) — probability of human authorship (equals1 - ai)credits_used— credits consumed by this scan
score.ai | Meaning |
|---|---|
| 0.80 - 1.0 | Very likely AI-generated |
| 0.50 - 0.79 | Mixed / uncertain |
| 0.20 - 0.49 | Probably human-written |
| 0.00 - 0.19 | Very likely human |
Plagiarism Detection — POST /api/v1/scan/plag
Send { "content": "<text>", "storeScan": false }. Returns:
score.percentUnique(0-100) — percentage of unique contentscore.percentDuplicated(0-100) — percentage matched elsewhere on the webmatches[]— array of{ url, matchedWords, percentage }for each source found
Combined Scan
Run both AI detection and plagiarism checks in parallel for comprehensive content verification. Flag content if AI score >= 0.5 or plagiarism >= 20%.
Credit Management
Check your balance via GET /api/v1/account/credits/balance. Credits are consumed per word, and AI + plagiarism scans cost credits separately. Use storeScan: false to avoid storing content in the dashboard.
Examples
Example 1: Checking marketing copy for originality
A content team lead verifies a freelancer's submitted blog post about cloud migration:
AI Detection:
POST https://api.originality.ai/api/v1/scan/ai
Headers: { "X-OAI-API-KEY": "oai-key-abc123...", "Content-Type": "application/json" }
Body: { "content": "Cloud migration is a transformative journey that organizations must carefully plan. It is essential to consider the various deployment models available, including public, private, and hybrid cloud solutions. Furthermore, a comprehensive migration strategy should address data security, compliance requirements, and cost optimization.", "aiModelVersion": "1", "storeScan": false }
Response:
{ "success": true, "score": { "ai": 0.92, "original": 0.08 }, "credits_used": 1 }
Plagiarism Check:
POST https://api.originality.ai/api/v1/scan/plag
Body: { "content": "...(same text)...", "storeScan": false }
Response:
{ "success": true, "score": { "percentUnique": 73, "percentDuplicated": 27 }, "matches": [{ "url": "https://example-cloud-blog.com/migration-guide", "matchedWords": 42, "percentage": 22 }], "credits_used": 1 }
Result: Flagged — AI score 92%, plagiarism 27% duplicated.
Total credits used: 2.
Example 2: Verifying an original product review
An e-commerce site checks a customer-submitted product review:
AI Detection:
POST https://api.originality.ai/api/v1/scan/ai
Body: { "content": "I bought this blender last March after my old Vitamix finally died (RIP, 8 years of smoothies). The Ninja BN701 is louder than I expected — my cat literally bolts out of the kitchen — but it crushes frozen mango like nothing. The lid seal is a bit finicky, learned the hard way when I repainted my ceiling with acai. For $89 though, no complaints.", "aiModelVersion": "1", "storeScan": false }
Response:
{ "success": true, "score": { "ai": 0.04, "original": 0.96 }, "credits_used": 1 }
Plagiarism Check:
Response:
{ "success": true, "score": { "percentUnique": 100, "percentDuplicated": 0 }, "matches": [], "credits_used": 1 }
Result: Passes both checks — AI score 4%, 100% unique content.
Guidelines
- Minimum 50 words required for AI detection
- Best accuracy for English; other languages are supported but less reliable
- Plagiarism check only works for publicly indexed web content
- Heavily paraphrased AI text may evade detection
- Does not detect AI in images, code, or structured data
- Budget credits for bulk runs: estimate ~1 credit per 100 words per scan type
- Handle HTTP 402 (insufficient credits) and 429 (rate limited) gracefully
- Always pair automated detection with human review for final decisions