Facts-Checking Webz.io’s on-demand fact checking uses AI to automatically identify factual claims in online text, such as news articles, blog posts, or forum posts. Each claim is then cross-verified by searching the web for other sources that support or refute it. The output clearly indicates whether the claim is Verified, False, or Unverified (when no references are found).

Want to see it in action? Try it out in our Demo or Playground environments.

Endpoint

This is the dedicated endpoint for the Fact-Check feature: https://api.webz.io/fact-check

API Calls

It can be used with HTTP GET and POST requests.

The table below outlines the required fields for each call, depending on the HTTP request type:

Param	Description	HTTP request	Comment
uuid	the post's uuid	GET
post_text	the text to analyze	POST	expected to include both 'title' + 'text' fields
post_link	the link to the post	POST
date	post's published date	POST
token	user's token	GET, POST

Expected structure:

https://api.webz.io/fact-check?token=[USER_TOKEN]&uuid=[POST_UUID]

https://api.webz.io/fact-check?token=[USER_TOKEN]&post_text=[POST_TITLE+POST_TEXT]&post_link=[POST_LINK]&date=[POST_PUBLISHED_DATE]

Limitations:

Fact-checking requires an input length of no less than 100 and no more than 10,000 characters.

Output Reference

The following table shows the fields returned by the API:

Field Name	Description	Comment
bias	shows the detected political bias of the site
claim	claim extracted from the original post text
verified	indicates whether the extracted claim has been verified	possible values: true, false, unverified
references	list of sources cited to claim verification
text	reference text supporting the claim verification
link	reference link supporting the claim verification

Response example:

{
  "bias": "left",
  "claims": [
    {
      "claim": "Iran's Supreme Leader Ayatollah Ali Khamenei has l...",
      "verified": "true",
      "references": [
        {
          "text": "Iran leader Khamenei sees his inner circle hollowed out ...",
          "link": "https://www.reuters.com/world/middle-east/i..."
        }
      ]
    },
    {
      "claim": "The loss of these advisers has created significant..",
      "verified": "true",
      "references": [
        {
          "text": "Iran leader Khamenei sees his inner circle hollowed ou...",
          "link": "https://www.cnn.com/world/middle-east/iran-lead..."
        }
      ]
    }
  ]
}

Error Handling

The table below lists the possible error codes our API response might return for improper request:

Error Code	Description
204	No content available - no relevant facts were found
400	Invalid request - a valid UUID is required
400	Invalid request - text length must be between 100 and 3000 characters
400	Invalid request - post_text, post_link, post_date only supported with POST requests
401	Unauthorized - token missing or incorrect
402	Not enough API calls available

API Credits

Fact-Check is offered as a premium feature. While a regular NBDR request counts as 1 API call, every Fact-Check request counts as 5 API calls toward the user’s total usage.