hollerback: Signal for your AI agents
A couple days ago I posted about goose-signal-gateway, a rough proof-of-concept that let you text your local Goose instance from Signal. It worked. The core loop was implemented, I was using it, and I wanted to share it while the code was still honest about what it was.
Since then I’ve done a proper pass on it. The project is now called hollerback, it’s on PyPI, and it’s meaningfully more capable than what I described two days ago. Here’s what changed and why.
Why “hollerback”
The original name reflected the implementation: a gateway between Signal and Goose. As I kept building it became clear the thing wasn’t really a Goose-specific gateway. It was a Signal number that any AI agent could use. Goose is still the primary target but a rename felt right.
Two use cases, one phone
The clearest way I’ve found to describe hollerback is a dedicated Signal number to share with your agents. There are two primary use cases today.
Use case 1: Goose is live and waiting. Someone messages the number, Goose picks up and replies: unattended, session-aware, in real time. This is the use case from the April 18 post.
Use case 2: An authorized agent can use the number to send messages. Any MCP client (Claude CLI, Goose Desktop, Cursor, Claude Desktop) connects to hollerback’s MCP endpoint via a standard HTTP Bearer token and gets tools to send Signal messages, list paired contacts, and read inbound traffic. If you’re in a Claude session and want to send someone a Signal message, you can. If you want Goose to notify you on Signal when a long task finishes, it can.
They share one process, one contact list, one phone number. You can run either use case alone or both together.
What’s working today
- Signal to Goose: inbound messages create or resume goosed sessions, Goose replies stream back to Signal
- Typing indicators while Goose is processing; read receipts on delivery
- Pairing flow for unknown senders: an unknown number gets a code; you approve it via CLI before the bot responds
- MCP server on port 7322 with four tools:
get_signal_identity,list_signal_contacts,send_signal_message,get_messages - Per-agent Bearer auth: multiple agents can share one Signal number, each with its own key
- Graceful operation without Goose Desktop: messages buffer when goosed is unreachable, auto-replies resume on reconnect
- systemd user service,
hollerback.service - Running on Fedora, smoke-tested in production
Install
uv tool install hollerback
hollerback setup
hollerback start --detach
Or from source at github.com/theronconrey/hollerback. Full setup instructions in the README.
The project is really early. I’m settling in where I can help, and I’m looking forward to engaging with the Goose team!