Articles on: Developer API

Detector API


Try it Out


You can test out the API without code by going to the FastAPI link with your web browser: https://ai-detect.undetectable.ai/docs


Authentication


Undetectable.AI uses API keys to allow access to the API. You can get your API key at the top of the page in our developer portal.


UD expects for the API key to be included in all API requests to the server in a request body that looks like the following:


key: YOUR API KEY GOES HERE


You must replace YOUR API KEY GOES HERE with your personal API key.


For web socket scenarios, you will need to send the users id as part of the url. You can get your User ID at the top of the page in our developer portal.


UD expects for the users User ID to be included in the url of all web socket requests. The documentation will look like the following:


**POST ** https://ai-detect.undetectable.ai/ws/$USER_ID


You must replace $USER_ID with your personal User Id.


AI Detector


Detect


This endpoint allows you to submit text for AI detection. At least 200 words are recommended for best accuracy.


**POST ** https://ai-detect.undetectable.ai/detect


ThresholdThis endpoint returns a "result" score from 1-100. For best accuracy, any score under 50 is considered definitely human. 50-60 is possible AI. Over 60 is definite AI. This is the most accurate result, with 99%+ accuracy. The scores for other detectors, such as Writer and Copyleaks, are approximate and not as accurate as the main "result" score.


Line breaksIf you're sending data as JSON, line breaks should be encoded as \n inside the string. Here's how you can send text like this:
On Citizen science
Citizen science involves the public participating in scientific research. This can take many forms, collecting data on local wildlife populations to analyzing astronomical images. Citizen science projects allow researchers to gather large amounts of data and engage the public in the process. By participating, individuals contribute to valuable research while gaining a deeper understanding of the scientific world around them.


Example Request


curl -X 'POST' \
'https://ai-detect.undetectable.ai/detect' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"text": "On Citizen science\nCitizen science involves the public participating in scientific research. This can take many forms, collecting data on local wildlife populations to analyzing astronomical images. Citizen science projects allow researchers to gather large amounts of data and engage the public in the process. By participating, individuals contribute to valuable research while gaining a deeper understanding of the scientific world around them.",
"key": "YOUR-API-KEY-GOES-HERE",
"model": "xlm_ud_detector",
"retry_count": 0
}'


Here, the request input must be less than 30,000 words.


Example Response


{
"id": "77565038-9e3d-4e6a-8c80-e20785be5ee9",
"input": "Citizen science involves the public participating in scientific research. This can take many forms, collecting data on local wildlife populations to analyzing astronomical images. Citizen science projects allow researchers to gather large amounts of data and engage the public in the process. By participating, individuals contribute to valuable research while gaining a deeper understanding of the scientific world around them.",
"model": "xlm_ud_detector",
"result": null,
"result_details": null,
"status": "pending",
"retry_count": 0
}


The response contains the server-assigned ID of the document. At this point the document is now enqueued for processing. You can use the /query API endpoint to query the status of the AI Detection request. The average time to complete an AI Detection check is between 2-4 seconds. It may take longer depending on word count.


Query


This endpoint accepts a document id returned by the /detect request. And returns the status of the document submission as well as the result of the AI Detection operation as handled by various third-party AI detectors.


**POST ** https://ai-detect.undetectable.ai/query


Example Request


curl -X 'POST' \
'https://ai-detect.undetectable.ai/query' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"id": "DOCUMENT-ID-GOES-HERE"
}'


Example Response


{
"id": "77565038-9e3d-4e6a-8c80-e20785be5ee9",
"model": "xlm_ud_detector",
"result": 12.0,
"result_details": {
"scoreGptZero": 50.0,
"scoreOpenAI": 0.0,
"scoreWriter": 0.0,
"scoreCrossPlag": 0.0,
"scoreCopyLeaks": 50.0,
"scoreSapling": 0.0,
"scoreContentAtScale": 0.0,
"scoreZeroGPT": 50.0,
"human": 88.0
},
"status": "done",
"retry_count": 0
}


Here, "result": 88.0 indicates the AI-ness of the input. This means that given it is greater than the 50% threshold, the text is AI-generated. Similarly the values under the result_details indicate the Human-ness of the input. For example "scoreZeroGPT": 50.0 signifies that the text is likely 50% human-written as per ZeroGPT. The Same goes for the rest of the other detectors.


Check User Credits


This endpoint accepts the users apikey via the header. And returns users credit details.


**GET ** https://ai-detect.undetectable.ai/check-user-credits


Example Request


curl -X 'GET' \
'https://ai-detect.undetectable.ai/check-user-credits' \
-H 'apikey: YOUR API KEY GOES HERE' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \


Example Response


{
"baseCredits": 10000,
"boostCredits": 1000,
"credits": 11000
}


Sentence Level AI Detection

The sentence-level AI Detector runs on top of a WebSocket-based protocol.


Here are the necessary steps needed to get sentence-level results for your text.

  • Connect to the WebSocket
  • Listen for all events received from the WebSocket
  • Send a document_watch request
  • Receive a document_id event
  • Take the id generated by the document_id response and submit a document for AI Detection
  • Start receiving document_chunk events. document_chunk events will return each sentence together with the sentence-level result
  • When the document finishes processing, you will receive a document_done event.


This section will describe the necessary steps to connect, send a document for processing, and listen to the sentence stream until it finishes.


Connect to the WebSocket


This endpoint allows you to establish the WebSocket connection


**POST ** https://ai-detect.undetectable.ai/ws/$USER_ID


Example code:


ws = new WebSocket("wss://https://ai-detect.undetectable.ai/ws/1722238709737x2194626580942121212");


Listen for all events received from the WebSocket


Once the WebSocket connection is established, listen to events sent through the WebSocket connection.


Example code:

ws.addEventListener("message", (event) => {
console.log("Message from server ", event.data);
});


Send a document_watch request


Send interest in sending a document by sending a document_watch request on the WebSocket


Example code:

ws.send(JSON.stringify({
"event_type": "document_watch",
"api_key": "$API_KEY",
}))


Receive a document_id event


After sending a document_watch event, the server returns a document_id event.


Example response:

{
"event_type": "document_id",
"success": true,
"document_id": "512da191-166926922-44cb-81c6-191ae3a807aa"
}


Submit an AI Detection Request


Take the id generated by the document_id response and submit a document for AI Detection


**POST ** https://ai-detect.undetectable.ai/detect


Example Request


curl -X 'POST' \
'https://ai-detect.undetectable.ai/detect' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"text": "Citizen science involves the public participating in scientific research. This can take many forms, collecting data on local wildlife populations to analyzing astronomical images. Citizen science projects allow researchers to gather large amounts of data and engage the public in the process. By participating, individuals contribute to valuable research while gaining a deeper understanding of the scientific world around them.",
"key": "YOUR-API-KEY-GOES-HERE",
"model": "xIm_ud_detector",
"id": "512da191-166926922-44cb-81c6-191ae3a807aa"
}'


Example Response


{
"id": "512da191-166926922-44cb-81c6-191ae3a807aa",
"input": "Citizen science involves the public participating in scientific research. This can take many forms, collecting data on local wildlife populations to analyzing astronomical images. Citizen science projects allow researchers to gather large amounts of data and engage the public in the process. By participating, individuals contribute to valuable research while gaining a deeper understanding of the scientific world around them.",
"model": "xIm_ud_detector",
"result": null,
"result_details": null,
"status": "pending",
"retry_count": 0
}


Receive sentence level results


Start receiving document_chunk events. document_chunk events will return each sentence together with the sentence level result


Example responses:

{
"event_type": "document_chunk",
"document_id": "512da191-166926922-44cb-81c6-191ae3a807aa"
"model": "xIm_ud_detector",
"chunk": "Citizen science involves the public in scientific research.",
"result": 0.714
}


When the document finishes processing, you will receive a document_done event.


Example responses:

{
"event_type": "document_done",
"document_id": "512da191-166926922-44cb-81c6-191ae3a807aa"
"model": "xIm_ud_detector"
}


Below is an example sequence as returned by the WS stream.


Example Document Stream

Handling exceptional circumstances


If for some reason the server encounters an error while doing the humanization, a document_error event will be sent to the websocket client. The client should act as appropriate, for example a UI will show an error message.


For example, the server will send a REQUEST_TIMEOUT error code when it takes more than 20 seconds across chunk events.

{
"event_type": "document_error",
"document_id": "512da191-166926922-44cb-81c6-191ae3a807aa"
"error_code": "REQUEST_TIMEOUT",
"message": "Request timeout. Took 20 seconds.",
}


Cancellations


There will be instances when the UI would want to cancel the operation. The user decides to close the window, or cancels the event explicitly
When this happens you should sent a document_halt event


Example responses:

{
"event_type": "document_halt",
"document_id": "512da191-166926922-44cb-81c6-191ae3a807aa"
}


Errors


Most errors will be from incorrect parameters being sent to the API. Double check the parameters of each API call to make sure it's properly formatted, and try running the provided example code.


The generic error codes we use conform to the REST standard:


Error Code

Meaning

400

Bad Request -- Your request is invalid.

403

Forbidden -- The API key is invalid, or there aren't sufficient credits (0.1 per word).

404

Not Found -- The specified resource doesn't exist.

405

Method Not Allowed -- You tried to access a resource with an invalid method.

406

Not Acceptable -- You requested a format that isn't JSON.

410

Gone -- The resource at this endpoint has been removed.

422

Invalid Request Body -- Your request body is formatted incorrectly or invalid or has missing parameters.

429

Too Many Requests -- You're sending too many requests! Slow it down!

500

Internal Server Error -- We had a problem with our server. Try again later.

503

Service Unavailable -- We're temporarily offline for maintenance. Please try again later.


Common Issues and Solutions


Authentication Issues


"User verification failed" (403)

  • Cause: Invalid or expired API key
  • Solution:
  1. Verify your API key is correct
  2. Check if your API key is active in your account
  3. Try regenerating your API key


"Not enough credits" (403)

  • Cause: Insufficient credits for text processing
  • Solution:
  1. Check your remaining credits using /check-user-credits
  2. Purchase additional credits if needed
  3. Use shorter text inputs to consume fewer credits


Input Validation Issues


"Input text cannot be empty" (400)

  • Cause: Empty or whitespace-only text submitted
  • Solution:
  1. Ensure your text input is not empty
  2. Remove any leading/trailing whitespace
  3. Check if text encoding is correct


"Input email is empty" (400)

  • Cause: Missing email for URL processing
  • Solution:
  1. Provide a valid email address when submitting URLs
  2. Check email format is correct


Processing Issues


"Request timeout" (WebSocket)

  • Cause: Document processing took too long (>120 seconds)
  • Solution:
  1. Try with a smaller text input
  2. Check if the service is experiencing high load
  3. Retry the request


Document Status "failed"

  • Cause: Processing failed for various reasons
  • Solution:
  1. Check if input text meets minimum requirements
  2. Verify text is in a supported format
  3. Try with a different model
  4. Contact support if issue persists


WebSocket Connection Issues


Connection Drops

  • Cause: Network issues or server disconnects
  • Solution:
  1. Check your network connection
  2. Implement reconnection logic
  3. Verify WebSocket URL is correct


"User not found" (WebSocket)

  • Cause: Invalid user ID in WebSocket connection
  • Solution:
  1. Verify user ID is correct
  2. Ensure user account is active
  3. Re-authenticate if needed


Updated on: 12/06/2025

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