---
updatedAt: 2026-09-30T10:53:38.000Z
agentTools:
  projectIndex: https://docs.hud.io/llms.txt
---

# Quick Start

Set up your first agentic workflow — a PR blast-radius check on GitHub Actions — in about 10 minutes.

This guide walks you through one complete workflow end to end: the **Blast Radius** recipe running on **GitHub Actions**. When you open a pull request, an agent maps the changed code to its real production usage and posts a 0–100 risk score as a PR comment.

It's the fastest way to see an agentic workflow in action. Once it's working, swap in any other recipe or runner from the rest of this section.

> 📘 What you'll need
>
> * A GitHub repository whose service(s) are instrumented with Hud ([Node.js](https://docs.hud.io/docs/nodejs-installation-guide), [Python](https://docs.hud.io/docs/hud-python-installation), [Java](https://docs.hud.io/docs/java-installation)) and reporting production data.
> * A **Hud MCP key** — [app.hud.io → Settings → API keys](https://www.app.hud.io/settings/api-keys?environment=production).
> * An **Anthropic API key** — [console.anthropic.com](https://console.anthropic.com). (Using AWS Bedrock instead? See [model authentication in the FAQ](https://docs.hud.io/docs/agentic-workflows-faq).)

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***

## Step 1 — Copy the workflow files

From the [`github-actions-claude` template](https://github.com/code-hud/hud-agentic-workflows-recipes/tree/main/full-examples/blast-radius-github-actions), copy these three files into your repo, **keeping the same paths**:

```
.github/workflows/pr-blast-radius.yml      # the workflow + PR trigger
.github/actions/blast-radius/action.yml    # installs Claude CLI, configures Hud MCP, runs the prompt
.github/actions/blast-radius/blast-radius-prompt.txt   # the recipe prompt
```

The `action.yml` writes a `.mcp.json` that wires up the Hud MCP server, then runs the prompt against the PR diff.

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***

## Step 2 — Add your secrets

In GitHub: **Settings → Secrets and variables → Actions → New repository secret**. Add both:

| Secret              | Where it comes from                                                                                 |
| ------------------- | --------------------------------------------------------------------------------------------------- |
| `HUD_MCP_KEY`       | [app.hud.io → Settings → API keys](https://www.app.hud.io/settings/api-keys?environment=production) |
| `ANTHROPIC_API_KEY` | [console.anthropic.com](https://console.anthropic.com)                                              |

> 🚧 Fork safety
>
> This workflow uses the `pull_request_target` trigger so it can post comments and read secrets. That trigger runs in the context of your base branch **with access to secrets**, including on PRs from forks. Only enable it on repos where you trust contributors, or add an author/label guard. See [running on pull requests safely](https://docs.hud.io/docs/agentic-workflows-faq).

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***

## Step 3 — Test it manually

Before wiring it to PRs, confirm it runs:

1. Go to **Actions → PR Blast Radius → Run workflow**.
2. Watch the logs. The agent will connect to Hud, resolve the changed functions, and produce a report.

If you see a blast-radius score in the run output, the plumbing works.

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***

## Step 4 — Open a pull request

Open (or update) a PR that touches instrumented code. Within a minute or two, the workflow runs and the agent posts a comment like this:

<Image align="center" caption="Blast Radius score posted as a PR comment" src="https://files.readme.io/REPLACE-WITH-blast-radius.png" />

The comment includes:

* **A 0–100 Blast Radius Score** and a risk level (Low / Medium / High / Critical).
* **Affected endpoints and functions**, ranked by production traffic.
* **A score breakdown** explaining the rating.

If the PR doesn't touch any Hud-tracked functions, the agent exits early and says so — no noise.

<br />

***

## What just happened

```
PR opened
   │
   ▼
GitHub Actions runs the composite action
   │   • installs the Claude Code CLI
   │   • writes .mcp.json with your HUD_MCP_KEY
   ▼
Agent runs the blast-radius prompt
   │   • extracts changed function names from the diff
   │   • queries Hud for their production metrics
   │   • scores impact and ranks affected endpoints
   ▼
Agent posts the report as a PR comment
```

<br />

***

## Next steps

* **Tune it.** The prompt accepts a config block (lookback window, scoring weights, row limits). See the [Recipe Catalog](https://docs.hud.io/docs/agentic-workflows-recipes).
* **Pick a different runner.** Prefer Cursor, gh-aw, or a scheduled Claude routine? See [Choosing a Runner](https://docs.hud.io/docs/agentic-workflows-runners).
* **Add more recipes.** Schedule a [Weekly Report](https://docs.hud.io/docs/agentic-workflows-recipes) or gate deploys with a [Rollback Check](https://docs.hud.io/docs/agentic-workflows-recipes).
* **Check the FAQ.** Cost, security, and scoping are covered in [FAQ & Best Practices](https://docs.hud.io/docs/agentic-workflows-faq).

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