# Langfuse prompt version changed notifications on your phone

> Get a push notification when a Langfuse prompt version is created, relabeled (for example promoted to production) or deleted.

- Company: Langfuse (https://www.justpush.io/recipes/langfuse)
- Event: `prompt-version` (Prompt version)
- Tags: AI, Monitoring
- Install: https://studio.justpush.io/recipes/langfuse/prompt-version
- Web page: https://www.justpush.io/recipes/langfuse/prompt-version

## Setup

1. Click Install in Studio and sign in. The recipe is added to your account and you get a personal webhook URL.
2. Follow the setup notes below: Prompt version changed lives under Prompts > Automations or Project > Alerts.
3. Choose the Webhook action and paste your webhook URL (shown in Studio after install) as the URL.
4. Save the automation or alert.
5. In Langfuse, go to **Prompts → Automations → Create Automation**, pick the prompt events (and optionally which prompts), choose the **Webhook** action and paste the URL above.
6. Moving a label (for example `production`) from one version to another sends **two** `updated` events: one for the version that gains it and one for the version that loses it, so expect two pushes.
7. "View prompt" links go to `cloud.langfuse.com`; change `LANGFUSE_URL` at the top of the code for the US region or a self-hosted Langfuse.
8. Langfuse signs each request with `x-langfuse-signature` (HMAC-SHA256), but JustPush doesn't check it yet, so keep your endpoint URL private.

## Code

Studio calls `handleRequest(request)` with the incoming webhook (`{ method, headers, body, query, raw }`) and sends the message object it returns. Returning `null` sends nothing.

```js
// Langfuse → prompt version created, updated or deleted
// Fires when a Langfuse prompt automation with a Webhook action sees a prompt change.
// Docs: https://langfuse.com/docs/prompt-management/features/webhooks-slack-integrations

// Where "View prompt" links go. Change this for the US region
// (https://us.cloud.langfuse.com) or a self-hosted Langfuse.
const LANGFUSE_URL = "https://cloud.langfuse.com"

const ACTIONS = {
    created: "📝 New prompt version",
    updated: "🏷️ Prompt version updated",
    deleted: "🗑️ Prompt version deleted",
}

// Look a key up in one of the tables above, ignoring inherited names like "toString".
function pick(table, key, fallback) {
    return Object.prototype.hasOwnProperty.call(table, key) ? table[key] : fallback
}

// Only link to real http(s) URLs.
function link(url, cta) {
    return typeof url === "string" && /^https?:\/\//.test(url) ? [{ cta, url }] : []
}

function handleRequest(request) {
    const body = request.body || {}
    const prompt = body.prompt

    // Guard: only prompt-version events, so alerts on this integration stay quiet.
    if (body.type !== "prompt-version" || !prompt?.name) {
        console.log(`Ignoring Langfuse "${body.type ?? "unknown"}" webhook`)
        return null
    }

    const title = pick(ACTIONS, body.action, "📝 Prompt changed")
    const labels = Array.isArray(prompt.labels) ? prompt.labels.filter((label) => typeof label === "string") : []
    const live = labels.includes("production")
    const details = [
        labels.length ? `labels: ${labels.join(", ")}` : null,
        typeof prompt.commitMessage === "string" && prompt.commitMessage.trim() ? `“${prompt.commitMessage.trim()}”` : null,
    ].filter(Boolean)
    const url = prompt.projectId
        ? `${LANGFUSE_URL}/project/${encodeURIComponent(prompt.projectId)}/prompts/${encodeURIComponent(prompt.name)}`
        : null

    return {
        title,
        message: `${prompt.name}${prompt.version != null ? ` v${prompt.version}` : ""}` + (details.length ? ` · ${details.join(" · ")}` : ""),
        topic: "Langfuse",
        // A change touching the production label is worth noticing; everything else is routine.
        priority: live || body.action === "deleted" ? 0 : -1,
        buttons: body.action === "deleted" ? [] : link(url, "View prompt"),
    }
}
```

## Langfuse prompt-version webhook payload (sample)

```json
{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "type": "prompt-version",
  "action": "created",
  "prompt": {
    "id": "prompt_abc123",
    "name": "movie-critic",
    "tags": [
      "entertainment"
    ],
    "type": "text",
    "config": {
      "temperature": 0.7
    },
    "labels": [
      "production",
      "latest"
    ],
    "prompt": "As a {{criticLevel}} movie critic, rate {{movie}} out of 10.",
    "version": 3,
    "createdAt": "2026-09-29T10:30:00Z",
    "projectId": "xyz789",
    "updatedAt": "2026-09-29T10:30:00Z",
    "commitMessage": "Improved critic persona"
  },
  "timestamp": "2026-09-29T10:30:00Z",
  "apiVersion": "v1"
}
```

## FAQ

### Does this work on iPhone and Android?

Yes. Install the JustPush app from the App Store or Google Play and sign in. Every phone signed in to your account gets the notification.

### Do I need to write code?

No. Install the recipe in Studio, paste your webhook URL into Langfuse and you are done. The code is there if you want to change the text, the sound or the buttons.

### Can I change what the notification says?

Yes. After install the recipe's code is yours. Edit it in Studio and test it against the sample payload before you save.

### What does it cost?

JustPush is free for 30 days. After that it's $19.99 a year, or $39.99 once. There is no extra charge for recipes.