Attach files to a message

You can attach files to a message so Captain can use what they say, for example an old resume to copy your work history from. Attachments work in the dashboard panel and in the Captain app.

Attach a file

1. In the message box, select Attach files and choose the files. You can also paste a file or drop it onto the message box.
2. Type what Captain should do with them. A file without a message is also accepted.
3. Send the message.

To take a file off before sending, select the remove button next to its name.

What you can attach

Type	Formats
Images	PNG, JPEG, WebP
PDF	.pdf
Word	.docx
Plain text	.txt, .md

• Up to 3 files per message.
• Each file up to 5 MB.

Captain checks the type from the file’s content, not from its name. A file renamed to .pdf that is not a PDF is refused.

What Captain does with them

PDF and Word documents. Captain reads the text out of the document and gives that text to the AI model with your message. From a PDF it reads the first 30 pages. Very long text is cut off at a fixed length. A PDF with no readable text, such as a scan made only of pictures, is refused.

Images. Captain re-saves the image before sending it to the model. This scales large images down to at most 2,000 pixels on the longest side and removes hidden details such as the location and camera. The model sees the image for that one message only.

Plain text. Captain passes the text on as it is, with the same length cap as documents.

Captain reads attachments; it cannot place them in your profile. To change a photo or a file in the profile, use the dashboard.

What is kept

The files themselves are never stored. They are read for the message and then discarded.

Captain keeps a record of each attachment: its name, type and size. For documents and text files it also keeps the text it read, so later messages in the same conversation can still use it. For images it keeps no content at all.

Clear conversation deletes this, including text read from your files.

With your own model

Image attachments are offered only when Reads images is turned on for your model. See Set it up.

If a file is refused

When a file is refused, the message is not run and nothing is changed. Remove the file or fix it, and send again.

Message	What to do
“… is larger than 5 MB.”	Attach a smaller file.
“Attach at most 3 files.”	Send the rest in a second message.
“… is not a file type Captain accepts here.”	Use one of the formats above.
“… has no text Captain can read.”	The document has no text layer. Paste the text into your message instead.
“… could not be read.”	The file may be damaged or protected. Try saving it again.
“Captain can’t read images right now. Describe what you need instead.”	The model in use does not read images. Type the details.

For what is sent to the AI model, see What is sent to the model.