Quick start (cloud)

Updated Aug 26, 2026View as Markdown

Put an agent in Slack, hosted on substructure.ai. You write one config file and run five commands. You do not run a server.

To run the engine on your own machine, with no account and no deployment, start with the local quick start.

Install the CLI

curl -fsSL https://subs.dev/cli.sh | bash
subs login

The script verifies the release checksum and installs to ~/.local/bin. Set SUBS_INSTALL_DIR to install elsewhere and SUBS_VERSION to pin a release. To install from npm instead: npm install -g @substructure.ai/cli.

subs login authenticates in your browser and stores a token under ~/.config/subs.

Write the config file

Create subs.toml in your project root.

subs.toml
name = "oncall-bot"

[llm.openrouter]
type = "openrouter"

[agent.oncall]
llm = "openrouter"
model = "anthropic/claude-sonnet-4-5"
system = "You are the on-call assistant."

[agent.oncall.slack]
name = "On-call"

[remote]
url = "https://api.substructure.ai"

[llm.openrouter] sets which provider to call. [agent.oncall] sets who calls it. [agent.oncall.slack] gives that agent a Slack app. [remote] makes the file describe a deployment, so every command on this page acts on the cloud. The file holds no keys.

Create the project

subs apply

Apply creates the project and writes its ID back into the file. Run it again after every change to the file.

Upload your LLM key

subs auth llm.openrouter

The command reads the key from stdin. Model calls run on your key.

Set up the Slack app

subs auth agent.oncall.slack

The command prints an app manifest. Go to api.slack.com/apps, choose Create New App, then From a manifest, and paste it in. Create the app and install it to your workspace.

Slack then shows you two values. Paste them back when the command asks.

  • The Bot User OAuth Token, under OAuth & Permissions.
  • The Signing Secret, under Basic Information.

Talk to the agent

Invite the bot to a channel and mention it, and it answers in the thread. Send it a DM and it answers every message.

The thread is the session. Later mentions continue the conversation.

Check what is left to do

subs doctor

Doctor lists every setup step that nobody has finished, and the command that finishes it.

Next steps

Add one thing at a time.