Document Add File API Error

Last updated: June 19, 2026

Do you get an error when trying to upload image files using the API?

S3 File Upload URL error:
SignatureDoesNotMatch
The request signature we calculated does not match the signature you provided. Check your key and signing method.>

Here are some troubleshooting steps, along with a video for your convenience!

1. Make sure the `filename` parameter in your POST to `documents/modify` and `documents/add` matches the filename that you upload. e.g. If I am uploading an image titled "tree.jpg", then I'll need to set the `filename` parameter of the `documents/add` method to "tree.jpg" exactly.

2. The URL expires after a short time, so you must PUT the file to thes3.amazonaws.com URL right after you get a result from the `documents/add` method. While testing, I usually call the PUT method to amazon within 30 seconds after the POST method to L2L.

3. Make sure you are including all required fields in the `documents/add` method.

Here is a video uploading a file using Postman:https
://www.loom.com/share/8b9e0456659443ca83cbdd4c32fa2a81