EventSubscription publicationUrl truncation | Experience Community
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EventSubscription publicationUrl truncation

  • June 17, 2026
  • 1 reply
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This is not documented on the various webhook API documentation pages, but there seems to be a limitation on the length of the PublicationUrl. It seem to be truncated at the 255 bytes boundary. This makes using some platforms webhooks receivers impossible without some kind of proxy. Examples of this would be PowerPlatform/LogicApps custom connectors that generates really long URL with long synthetic domains, path and a lot of parameters in querystring, running above 456 bytes, often more given that it also encodes the name of the flow using the trigger.

    1 reply

    Lpena
    Qualtrics Employee
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    • Lpena
    • Qualtrics Employee
    • July 9, 2026

    Hitting an unexpected character limit when you're trying to pass important webhook data is incredibly frustrating.

    While general Qualtrics query strings support up to 2,000 characters before hitting browser-based limitations, there actually is a known, stricter cap when it comes to the API's EventSubscriptions. The PublicationUrl field specifically has an undocumented limitation where it truncates right at the 255-byte boundary. This causes a massive headache if you are trying to route events directly into platforms like MS Power Automate, Logic Apps, or custom API connectors, which frequently generate long synthetic domains, paths, and query string parameters that easily exceed 400+ characters.

    Since the Qualtrics backend will cut the string off after 255 bytes, the most common community workaround is inserting a proxy layer or using a reliable 3rd-party URL shortener to mask the long endpoint before saving it to your subscription logic.

     

    This reply contains AI usage for clarity and language purposes.
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