> ## Documentation Index
> Fetch the complete documentation index at: https://docs.devhelm.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Your First HTTP Monitor

> Create your first DevHelm HTTP monitor to check a web endpoint in under 5 minutes

By the end of this guide, you'll have an HTTP monitor checking your endpoint every 60 seconds from multiple regions, with results visible in the Dashboard.

<Accordion title="Prerequisites">
  * DevHelm CLI installed (`npm install -g devhelm`) or an API token for REST calls
  * An API token set as `DEVHELM_API_TOKEN` — see [Authentication](/authentication)
  * A publicly accessible URL to monitor
</Accordion>

## Create the monitor

<Steps>
  <Step title="Pick your surface">
    Choose whichever method fits your workflow:

    <CodeGroup>
      ```bash CLI theme={null}
      devhelm monitors create \
        --name "My API Health" \
        --type HTTP \
        --url https://api.example.com/health \
        --frequency 60 \
        --regions us-east,eu-west
      ```

      ```yaml devhelm.yml theme={null}
      version: "1"
      monitors:
        - name: My API Health
          type: HTTP
          config:
            url: https://api.example.com/health
            method: GET
          frequencySeconds: 60
          regions:
            - us-east
            - eu-west
      ```

      ```bash API theme={null}
      curl -X POST https://api.devhelm.io/api/v1/monitors \
        -H "Authorization: Bearer $DEVHELM_API_TOKEN" \
        -H "Content-Type: application/json" \
        -d '{
          "name": "My API Health",
          "type": "HTTP",
          "config": {
            "url": "https://api.example.com/health",
            "method": "GET"
          },
          "frequencySeconds": 60,
          "regions": ["us-east", "eu-west"]
        }'
      ```
    </CodeGroup>

    If using YAML, deploy it:

    ```bash theme={null}
    devhelm deploy -f devhelm.yml
    ```
  </Step>

  <Step title="Verify it's running">
    Check that the monitor was created and is collecting results:

    ```bash theme={null}
    devhelm monitors list
    devhelm monitors get <monitor-id>
    ```

    You should see the monitor with status `ACTIVE` and check results appearing within 60 seconds.
  </Step>

  <Step title="View results">
    Open the Dashboard to see check results, response times, and status codes plotted over time. Or fetch results via the CLI:

    ```bash theme={null}
    devhelm monitors checks <monitor-id> --limit 5
    ```
  </Step>
</Steps>

## Add assertions

By default, an HTTP monitor passes if it gets any response. Add assertions to define specific pass/fail criteria:

<CodeGroup>
  ```bash CLI theme={null}
  devhelm monitors create \
    --name "My API Health" \
    --type HTTP \
    --url https://api.example.com/health \
    --frequency 60 \
    --regions us-east,eu-west \
    --assertion 'status_code=200' \
    --assertion '{"severity":"fail","config":{"type":"response_time","thresholdMs":2000}}'
  ```

  ```bash API theme={null}
  curl -X POST https://api.devhelm.io/api/v1/monitors/<monitor-id>/assertions \
    -H "Authorization: Bearer $DEVHELM_API_TOKEN" \
    -H "Content-Type: application/json" \
    -d '{
      "severity": "fail",
      "config": {
        "type": "status_code",
        "expected": "200",
        "operator": "equals"
      }
    }'
  ```

  ```yaml devhelm.yml theme={null}
  monitors:
    - name: My API Health
      type: HTTP
      config:
        url: https://api.example.com/health
        method: GET
      frequencySeconds: 60
      regions:
        - us-east
        - eu-west
      assertions:
        - config:
            type: status_code
            expected: "200"
            operator: equals
          severity: fail
        - config:
            type: response_time
            thresholdMs: 2000
          severity: fail
  ```
</CodeGroup>

In the CLI, the repeatable `--assertion` flag is set at create time and accepts a shorthand DSL (`status_code=200`, `response_time<2000`, `ssl_expiry>=14`) or a JSON object when you need full control over severity and config. To add assertions to an existing monitor, use the assertions API (`POST /api/v1/monitors/{monitorId}/assertions`) as in the API tab.

Common assertions for HTTP monitors:

| Type            | What it checks                               |
| --------------- | -------------------------------------------- |
| `status_code`   | Response status equals or matches a pattern  |
| `response_time` | Response completes within a threshold        |
| `body_contains` | Response body includes a string              |
| `json_path`     | A JSON path evaluates to an expected value   |
| `header_value`  | A response header matches an expected value  |
| `ssl_expiry`    | TLS certificate is valid for at least N days |

For the full list, see [HTTP assertions](/monitoring/http/assertions).

## What happens next

Once your monitor is running:

* **Passing checks** appear as green dots in the Dashboard timeline
* **Failing checks** (assertion failures, timeouts, connection errors) appear as red dots
* **Incidents** are created automatically based on the monitor's [incident policy](/incidents/policies) — by default, 2 consecutive failures trigger a `DOWN` incident
* **Alerts** fire through your [notification policies](/alerting/notification-policies) when an incident is confirmed

## Next steps

<CardGroup cols={2}>
  <Card title="HTTP monitor reference" icon="globe" href="/monitoring/http/overview">
    All HTTP configuration options and assertion types.
  </Card>

  <Card title="First alert" icon="bell" href="/guides/first-alert">
    Get notified when this monitor fails.
  </Card>

  <Card title="Multi-region monitoring" icon="earth-americas" href="/guides/multi-region-monitoring">
    Reduce false positives with cross-region confirmation.
  </Card>

  <Card title="Monitoring as Code" icon="file-code" href="/guides/monitoring-as-code">
    Manage monitors in YAML and deploy from CI.
  </Card>
</CardGroup>