# HTTP Header Diff Monitor (`junipr/http-header-diff-monitor`) Actor

Compare previous/current HTTP headers and show exact added/removed/changed security/cache/CORS headers.

- **URL**: https://apify.com/junipr/http-header-diff-monitor.md
- **Developed by:** [junipr](https://apify.com/junipr) (community)
- **Categories:** Automation
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $6.50 / 1,000 snapshot compareds

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## HTTP Header Diff Monitor

Compare supplied HTTP header snapshots and emit added, removed, or changed header rows with security-aware severity.

### Inputs

- `inputItems`
- `maxChanges`
- `includeUnchanged`
- `includeReport`
- `maxChargeUsd`

```json
{
  "inputItems": [
    {
      "url": "https://www.iana.org",
      "oldHeaders": {
        "server": "cloudflare",
        "x-frame-options": "DENY",
        "cache-control": "public, max-age=3600",
        "content-security-policy": "upgrade-insecure-requests; default-src 'self' https://*.iana.org; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://www.google.com https://cse.google.com https://clients1.google.com; style-src 'self' 'unsafe-inline' https://www.google.com; child-src 'self' https://www.youtube.com https://clients1.google.com https://cse.google.com https://www.google.com/; img-src 'self' https://data.iana.org https://www.iana.org https://www.google.com https://www.googleapis.com https://clients1.google.com https://*.gstatic.com"
      },
      "newHeaders": {
        "server": "cloudflare",
        "x-frame-options": "DENY",
        "cache-control": "public, max-age=3600",
        "content-security-policy": "upgrade-insecure-requests; default-src 'self' https://*.iana.org; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://www.google.com https://cse.google.com https://clients1.google.com; style-src 'self' 'unsafe-inline' https://www.google.com; child-src 'self' https://www.youtube.com https://clients1.google.com https://cse.google.com https://www.google.com/; img-src 'self' https://data.iana.org https://www.iana.org https://www.google.com https://www.googleapis.com https://clients1.google.com https://*.gstatic.com",
        "strict-transport-security": "max-age=48211200; preload"
      }
    }
  ],
  "maxChanges": 2,
  "includeUnchanged": false,
  "includeReport": true,
  "maxChargeUsd": 1
}
```

The bundled exact input compares public HTTP and HTTPS response-header observations for IANA captured at 2026-07-12T05:03:20Z; it demonstrates the HSTS header added on the HTTPS response.

### Dataset

The actor emits structured, actor-specific evidence rows. Empty source input, or a comparison with no selected changes, produces no dataset rows.

### Billing

This actor uses pay-per-event billing with platform usage included in the configured event prices. Configured events are:

- `actor-start`
- `snapshot-compared`
- `change-detected`
- `digest-generated`
- `executive-report-generated`

Every dataset row and report artifact is charge-gated. A zero-dollar cap stops before work with no paid output.

### Use Cases

- Detect HSTS header removal
- Detect CSP header addition
- Compare Cache-Control values
- Detect a Server header change
- Export a security header diff

### Limitations

The actor compares supplied snapshots and does not fetch URLs or schedule monitoring. Header names are normalized case-insensitively; semantic equivalence inside complex header values is not inferred.

# Actor input Schema

## `inputItems` (type: `array`):

URLs with previous and current response headers.

## `maxChanges` (type: `integer`):

Hard cap for paid header-change rows.

## `includeUnchanged` (type: `boolean`):

Emit unchanged headers as paid comparison rows.

## `includeReport` (type: `boolean`):

Create charged Markdown and JSON report artifacts.

## `maxChargeUsd` (type: `number`):

Stop before an event would exceed this run budget.

## Actor input object example

```json
{
  "inputItems": [
    {
      "url": "https://www.iana.org",
      "oldHeaders": {
        "server": "cloudflare",
        "x-frame-options": "DENY",
        "cache-control": "public, max-age=3600",
        "content-security-policy": "upgrade-insecure-requests; default-src 'self' https://*.iana.org; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://www.google.com https://cse.google.com https://clients1.google.com; style-src 'self' 'unsafe-inline' https://www.google.com; child-src 'self' https://www.youtube.com https://clients1.google.com https://cse.google.com https://www.google.com/; img-src 'self' https://data.iana.org https://www.iana.org https://www.google.com https://www.googleapis.com https://clients1.google.com https://*.gstatic.com"
      },
      "newHeaders": {
        "server": "cloudflare",
        "x-frame-options": "DENY",
        "cache-control": "public, max-age=3600",
        "content-security-policy": "upgrade-insecure-requests; default-src 'self' https://*.iana.org; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://www.google.com https://cse.google.com https://clients1.google.com; style-src 'self' 'unsafe-inline' https://www.google.com; child-src 'self' https://www.youtube.com https://clients1.google.com https://cse.google.com https://www.google.com/; img-src 'self' https://data.iana.org https://www.iana.org https://www.google.com https://www.googleapis.com https://clients1.google.com https://*.gstatic.com",
        "strict-transport-security": "max-age=48211200; preload"
      }
    }
  ],
  "maxChanges": 2,
  "includeUnchanged": false,
  "includeReport": true,
  "maxChargeUsd": 1
}
```

# Actor output Schema

## `dataset` (type: `string`):

Structured rows emitted by the actor.

## `report` (type: `string`):

Run summary report stored in the default key-value store.

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {};

// Run the Actor and wait for it to finish
const run = await client.actor("junipr/http-header-diff-monitor").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {}

# Run the Actor and wait for it to finish
run = client.actor("junipr/http-header-diff-monitor").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"])
for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{}' |
apify call junipr/http-header-diff-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=junipr/http-header-diff-monitor",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/acts/00ZwE6XXhIqmJ1r26/builds/hFlhqwQsl3LxQ0j8Q/openapi.json