> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mythos.new/llms.txt
> Use this file to discover all available pages before exploring further.

# Chat attachments

> Attach images and files to a Mythos prompt via the + menu — photos the agent uses as visual references, and files committed to your project before the build.

You can attach images and files to a chat message before you send it. The **+** menu next to the
composer has two choices that mean two different things: **Upload photo** gives the agent a visual
reference it can *see*, and **Upload file** adds a file *into your project* that the agent can read and
work from. Attached items show as chips on your message; send the prompt and they go in with it.

The mental model: a photo is "look at this," a file is "use this." The menu item you pick — not the
file type — decides which.

<Note>**Cost:** sending a message with attachments runs a normal generation, so it costs the usual
**3 credits** (build) or **2 credits** (edit) — the same as any prompt. Attaching costs nothing on its
own. See [Credits & usage](/introduction/credits-and-usage).</Note>

## Why use it

* **Show, don't describe.** A screenshot of a layout you like communicates a design faster than a
  paragraph trying to describe it.
* **Build from your own data.** Hand the agent a CSV, a logo, or a document and ask it to use that in
  the project.
* **Fewer back-and-forth edits.** Giving the agent the real reference up front beats correcting it
  afterward.

## Upload photo vs upload file

The two menu items are not interchangeable — pick by intent.

| You pick         | What it's for                                         | What happens                                                      |
| ---------------- | ----------------------------------------------------- | ----------------------------------------------------------------- |
| **Upload photo** | A visual reference — a design, a screenshot, a mockup | The agent *sees* the image and uses it as a reference.            |
| **Upload file**  | A project file — data, a document, a logo to embed    | The file is committed into your project so the agent can read it. |

<Tip>To add an image as an actual asset in your project (a logo to embed) rather than as a reference
to look at, attach it via **Upload file**, not Upload photo.</Tip>

## How to attach

<Steps>
  <Step title="Open the + menu">
    Click **+** next to the chat composer to open the attach menu.
  </Step>

  <Step title="Choose Upload photo or Upload file">
    Pick **Upload photo** for a visual reference, or **Upload file** for a project file. Select the
    file from your device.
  </Step>

  <Step title="Review the chips">
    Each attachment appears as a chip on your message. Add more, or remove one before sending.
  </Step>

  <Step title="Send your prompt">
    Send as usual. Photos go to the agent as references; files are committed into the project before
    the agent starts working.
  </Step>
</Steps>

## Examples

Attach a screenshot as a reference (**Upload photo**), then prompt:

```
Match this layout — same hero structure and spacing, but use our brand colors.
```

Attach a data file (**Upload file**), then prompt:

```
Use this CSV as the seed data for the products page.
```

## Limitations & good to know

* **Up to 10 images per message.** That's the per-message cap for photos.
* **Files attached in chat are committed before the build runs**, so a build that fails, times out, or
  a plan you reject can't lose them.
* **Files are not published with your site.** A file you attach in chat is readable by the agent but is
  not served on your live site, so a screenshot with private details can't leak to a published URL. (To
  make something part of the public site, ask the agent to use it, or add it via the Files tab Upload.)
* **An attachment-only message still runs a full generation** and costs credits. To just store a file
  without building, use the Upload button in the [Files tab](/features/files-and-artifacts).
* **Text files in non-UTF-8 encodings are treated as binary.** A file in an encoding like Windows-1251
  may not be read as readable text.

## FAQ

<AccordionGroup>
  <Accordion title="What's the difference between Upload photo and Upload file?">Upload photo gives the agent an image to look at as a reference. Upload file adds a file into your project that the agent can read and use. Pick by what you want it to do, not by the file type.</Accordion>
  <Accordion title="How many images can I attach?">Up to 10 per message.</Accordion>
  <Accordion title="Does attaching a file cost credits?">Attaching is free. Sending the message runs a normal build or edit, which costs the usual credits.</Accordion>
  <Accordion title="Is my attached file public?">No. Files attached in chat are readable by the agent but are not served on your published site unless you ask the agent to use them in the site.</Accordion>
  <Accordion title="I just want to store a file, not build. How?">Use the Upload button in the Files tab — that stores a file without spending credits. Chat attachments always run a generation.</Accordion>
</AccordionGroup>

## Related

* [Files and artifacts](/features/files-and-artifacts) — where uploaded and generated files live.
* [Skills](/features/skills) — reusable instructions that apply across projects.
* [Credits & usage](/introduction/credits-and-usage) — what sending a prompt costs.