Attachments & image previews

Happier lets you attach local files directly to a message in both:

• a new session composer before the first message, and
• an existing session composer inside an active transcript.

This is different from Link file:

• Attachments send local files from your device into the session
• Link file references files that already exist in the current workspace

Use attachments when you want to send things like:

• screenshots
• exported logs
• design assets
• PDFs or docs from outside the repo
• generated output files that are not already in the workspace

How to add attachments

Happier supports several attachment flows depending on platform:

• All platforms: pick files with the attachment/file-picker flow
• Web: drag and drop files into the composer
• Web: paste clipboard files/images into the composer when the browser exposes them as files

You can attach both images and non-image files in the same message.

What you see before sending

Before you send the message, Happier keeps attachments as drafts in the composer.

In the new-session flow, those draft attachments are kept while you move around the same in-app flow, such as opening picker screens and returning to the composer.

They are still treated as temporary unsent draft state, not durable stored content. A full page reload or app restart can still clear unsent attachments.

Non-image files

Non-image files appear as attachment chips with the filename.

Images

Image attachments appear as inline thumbnails instead of plain filename chips.

This makes it easier to confirm:

• you picked the correct image
• the image order looks right
• you are not about to send the wrong screenshot

Remove before send

You can remove an attachment before sending it.

Upload progress

When you send a message with attachments, Happier uploads each file first and shows per-file progress in the composer:

• image tiles show an upload overlay with a percentage
• non-image chips show percentage progress inline

This is especially useful when you send multiple files together, because you can see which file is still uploading and which one already finished.

Previewing images before sending

Click an image thumbnail in the composer to open a larger preview.

The preview modal is designed for quick confirmation before send:

• the image takes the full modal body
• the filename stays in the header
• if multiple images are attached, you can move between them from the same modal

On web, the previous/next controls appear when you hover the image.

On touch/native surfaces, the navigation controls stay directly available because there is no hover state.

What happens when you send attachments

Happier keeps the attachment flow provider-agnostic.

When you send a message with attachments:

1. Happier uploads each file first
2. Happier stores the files in the configured attachment upload location
3. the sent message includes an attachments block with stable file paths
4. the message tells the agent to read those paths from disk before answering

This means attachments behave like real files in the session environment, not like provider-specific “inline binary parts”.

That has a few practical benefits:

• the same message history remains understandable across providers
• the agent can read the exact file path it was given
• image attachments and non-image attachments follow the same core workflow

How images behave after sending

Sent user messages keep their attachments in the transcript.

Inline transcript images

If an attachment is an image, Happier shows it inline in the message instead of only listing the filename.

This makes transcripts easier to scan when you shared:

• screenshots
• mockups
• diagrams
• exported charts

Shared image preview modal

Clicking an inline image in the transcript opens the same preview modal used by the composer.

That gives you a consistent image-viewing flow before and after send.

Non-image attachments

Non-image files still appear in the message attachments row and can be opened from there.

Very large or unavailable previews

Happier does not try to force every image into an inline preview.

If an image is too large for the in-app preview budget, or the preview cannot be loaded cleanly:

• the attachment still remains attached to the message
• Happier falls back to a placeholder/open-file path instead of pretending the preview succeeded

This protects transcript performance while preserving access to the underlying file.

Attachment storage location

You can control where Happier stores uploaded message attachments.

Open:

• Settings
• Attachments

Workspace directory (default)

Default behavior stores attachments inside the current workspace.

By default, Happier uses this workspace-relative directory:

.happier/uploads

This path is relative to the workspace root, which keeps attachments alongside the rest of the session’s project context.

OS temp

You can also store attachments in the operating system temporary directory instead of the workspace.

This is useful when:

• you do not want attachment files written into the repo/worktree
• the attachment is only temporary session input
• you want the upload flow without adding extra workspace files

Source-control ignore behavior

When workspace storage is enabled, Happier can also help keep attachment files out of normal source-control workflows.

Attachment settings let you choose the ignore strategy for workspace uploads.

This matters when you want the convenience of workspace-backed attachments without accidentally treating them as project files you intend to commit.

Limits and important things to know

Size limit

Attachment uploads still follow the normal maximum attachment size setting.

If a file is over that limit, Happier skips it and tells you why.

No separate image-count cap

Happier does not add a special “only a few images” composer rule on top of the normal attachment settings.

The main practical limit is still your configured file-size policy.

Images are still files

Image attachments get a better UI, but they still follow the same core attachment model as other files.

That means:

• the image is uploaded as a file
• the message stores a file-path reference
• the agent reads that file from the session environment

Attachments vs Link file

Use Attachments when the file starts on your device and needs to be brought into the session.

Use Link file when the file already exists in the workspace and you only want to reference it in your prompt.

Examples:

• Attachment: “Here is the screenshot I just took on my desktop”
• Link file: “Look at src/auth/login.ts and explain this bug”

Provider-specific note

Regular session messages support attachments through Happier’s shared attachment flow.

For routed Claude teammate messages, check the Claude provider page for the current attachment limitations on that flow.

See:

• Claude
• Subagents