Attachments
Image and file attachments are handled per agent, since not every provider CLI exposes the same native attachment API.
You can attach images and files to a message, but what actually happens to them depends on which agent you're sending to — AgentDock doesn't paper over that with a single fake-universal attachment format.
Native support where it exists
Codex and Antigravity both support receiving images directly through their own transports, so an attached image reaches those agents as a genuine image input. See Agent capabilities for exactly which agents support this.
Workspace-copy fallback
Where an agent (or attachment type) has no native support, AgentDock falls back to copying the file into the active workspace and referencing its path in the message instead of silently dropping it. File names are handled collision-safely, so attaching a second file with the same name doesn't overwrite the first.
Note
Claude Code has no native image-attachment API in AgentDock's current integration — attachments to a Claude Code session go through the workspace-copy fallback.