Quickstart

You ran web-security from the Quickstart and saw what an installed capability does. Now build one of your own. Scaffold the manifest, add one tool and one agent, install it into your local runtime, and drive it from the TUI.

Prerequisites

• The Dreadnode CLI installed and authenticated — see the Quickstart if you haven’t yet
• Python 3.11+
• A model provider configured (Authentication)

Scaffold the capability

dn capability init web-recon
cd web-recon

The scaffold creates capability.yaml and a starter agents/example.md. Add --with-skills or --with-mcp to scaffold those folders too. Tools live under tools/ — create the directory yourself when you write the first one.

Write a tool

Create tools/lookup.py:

import typing as t

from dreadnode import tool


@tool
def lookup_host(
    host: t.Annotated[str, "Hostname or IP to look up"],
) -> dict[str, str]:
    """Resolve a host and return basic metadata."""
    return {"host": host, "status": "reachable", "source": "stub"}

Type hints become the tool schema the model sees. typing.Annotated supplies the parameter description.

Write an agent

Create agents/recon.md:

---
name: recon
description: Investigate a host and summarize what you found.
model: anthropic/claude-sonnet-4-5-20250929
tools:
  '*': false
  lookup_host: true
---

You are a reconnaissance agent. Use `lookup_host` to investigate any host the user mentions and summarize the result in two sentences.

The '*': false line opts the agent out of every runtime tool by default. lookup_host: true enables the one you just wrote.

Confirm the manifest

Open capability.yaml and make sure it looks like this:

schema: 1
name: web-recon
version: 0.1.0
description: Basic host reconnaissance capability.

You don’t need to list agents: or tools: — the loader auto-discovers both when the keys are omitted.

Install locally

From the parent directory:

dn capability install ./web-recon

install validates the manifest and symlinks the directory into your local store at ~/.dreadnode/capabilities/. Edits to the source are live on the next runtime reload.

Drive it from the TUI

dn

Press Ctrl+P, open the Installed tab, and enable web-recon. Start a new session with /agent recon, then send a prompt like Look up example.com. The agent calls lookup_host and returns the stubbed result.

Next steps

• Swap the stub tool body for a real implementation — Tools
• Add an MCP server for anything that isn’t pure Python — MCP servers
• Add a background worker to stream results out of the runtime — Workers
• Publish the capability so your team can install it — Publishing