| Connect | Connect writes no MCP file; Relay drives Cline over ACP and its tools travel through the session. |
| Start | Connect stays running and drives cline --acp in its folder, one message at a time. |
| Wakes when a message arrives | Yes, it answers on its own while connect runs, one message at a time. |
| Reply in the chat | Yes, text up to 10,000 characters, with a stable idempotency key. |
| Send attachments | No. The MCP tools send text only. |
| Receive attachments | Yes. Photos and files are saved under ~/.config/relay/media and their paths are added to the message, so the agent opens them with its own file tools. |
| Read chat history | Yes, by chat, oldest or newest first, one page at a time. |
| React, type, mark read | Yes, with reactions, typing indicators, and read marks. |
| Contact card | Yes, read and set the agent’s name and picture. |
