<p align="center">
  <img src="assets/corenexis-logo.png" alt="Corenexis logo" width="88" height="88">
</p>

<h1 align="center">Corenexis API and MCP Server</h1>

<p align="center">
  9+ production REST APIs behind one API key, plus a remote MCP server so AI agents can use them.<br>
  PDF generation, OCR, email validation, image conversion, image CDN and QR codes.
</p>

<p align="center">
  <a href="https://api.corenexis.com">Website</a> ·
  <a href="https://api.corenexis.com/mcp">MCP guide</a> ·
  <a href="https://dash.corenexis.com/auth/signup">Get an API key</a> ·
  <a href="https://registry.modelcontextprotocol.io/v0/servers?search=com.corenexis/api">MCP Registry</a>
</p>

<p align="center">
  <img src="assets/corenexis-api-website.png" alt="Corenexis API Platform" width="760">
</p>

---

## What is the Corenexis API?

The [Corenexis API Platform](https://api.corenexis.com) is a set of production REST APIs for documents,
images and data quality. One key, one header, predictable JSON - and a free tier on every API.
The same APIs are available to AI assistants through a remote MCP server, so ChatGPT, Claude, n8n or your
own agent can generate a PDF, read a scanned receipt or validate an email in the middle of a conversation.

| | |
|---|---|
| **REST API** | `https://api.corenexis.com/<api>/v1` - header `x-api-key` |
| **MCP server** | `https://api.corenexis.com/mcp/server` - Streamable HTTP, API key |
| **Registry name** | `com.corenexis/api` on the [Official MCP Registry](https://registry.modelcontextprotocol.io) |
| **n8n** | Community node in [`Core-Nexis/n8n-nodes-corenexis-api`](https://github.com/Core-Nexis/n8n-nodes-corenexis-api) |
| **Dashboard** | https://dash.corenexis.com - keys, subscriptions, usage |

## APIs

| API | Endpoint | What it does | Docs |
|---|---|---|---|
| Markdown to PDF | `POST /markdown-to-pdf/v1` | Markdown into a print-ready PDF or page images | [docs](https://api.corenexis.com/markdown-to-pdf/docs/) |
| HTML to PDF | `POST /html-to-pdf/v1` | HTML and CSS rendered by a real browser engine into a PDF or screenshot | [docs](https://api.corenexis.com/html-to-pdf/docs/) |
| Image to Text (OCR) | `/image-ocr/v1` | Text out of photos, screenshots, scans and receipts | [docs](https://api.corenexis.com/image-ocr/docs/) |
| PDF to Text (OCR) | `/pdf-to-text/v1` | Text from PDFs, scanned pages included, as a background job | [docs](https://api.corenexis.com/pdf-to-text/docs/) |
| Email Validator | `/email-validator/v1` | Syntax, domain, mailbox and risk checks | [docs](https://api.corenexis.com/email-validator/docs/) |
| Disposable Email Detector | `/disposable-email-validator/v1` | Tell a throwaway address from a real one | [docs](https://api.corenexis.com/disposable-email-validator/docs/) |
| Image Conversion | `/image-conversion/v1` | Convert, resize and compress images | [docs](https://api.corenexis.com/image-conversion/docs/) |
| Image CDN | `/image-cdn/v3` | Host an image and get a fast delivery link | [docs](https://api.corenexis.com/image-cdn/docs/) |
| QR Code and Barcode | `/qr-barcode/v1` | QR, UPI QR, Code128, EAN-13 and UPC-A codes | [docs](https://api.corenexis.com/qr-barcode/docs/) |

Every request and response example: [`docs/apis.md`](docs/apis.md).

## Quick start

1. Sign up at https://dash.corenexis.com/auth/signup and create a key at https://dash.corenexis.com/api-keys.
2. Subscribe to the APIs you need (each has a free tier). One key works for all of them.
3. Call an API:

```bash
curl -X POST https://api.corenexis.com/email-validator/v1 \
  -H "x-api-key: your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"email": "john.doe@company.com"}'
```

## MCP server

Point any MCP client at `https://api.corenexis.com/mcp/server` with your key in `x-api-key`.

<details open>
<summary><b>Claude, Cursor, VS Code and other MCP clients</b></summary>

```json
{
  "mcpServers": {
    "corenexis": {
      "type": "http",
      "url": "https://api.corenexis.com/mcp/server",
      "headers": { "x-api-key": "your_api_key" }
    }
  }
}
```

</details>

<details>
<summary><b>Claude Code</b></summary>

```bash
claude mcp add --transport http corenexis https://api.corenexis.com/mcp/server \
  --header "x-api-key: your_api_key"
```

</details>

<details>
<summary><b>n8n</b></summary>

MCP Client node: connection **HTTP Streamable**, endpoint `https://api.corenexis.com/mcp/server`,
authentication **Header Auth** with name `x-api-key` and your key as the value.

</details>

<details>
<summary><b>curl</b></summary>

```bash
curl -X POST "https://api.corenexis.com/mcp/server" \
  -H "x-api-key: your_api_key" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
```

</details>

### Tools

| Tool | What it does | Quota |
|---|---|---|
| `corenexis_list_apis` | Every API with its tools, docs and subscribe links | free |
| `corenexis_account` | Check the key and the account | free |
| `corenexis_subscriptions` | Subscribed APIs with plan, status, renewal and usage | free |
| `corenexis_api_details` | One API's plans, features and limits | free |
| `markdown_to_pdf` | Markdown to PDF or images, returns a hosted link | 1 call |
| `html_to_pdf` | HTML and CSS to PDF or image with a browser engine | 1 call |
| `image_to_text` | OCR of a photo, screenshot or scan from a URL or base64 | 1 call |
| `pdf_to_text` | Start PDF text extraction, returns a `job_id` | 1 call |
| `pdf_to_text_status` | Collect a `pdf_to_text` result | free |
| `email_validate` | Full email check: syntax, domain, mailbox, risk | 1 call |
| `disposable_email_check` | Is the address from a disposable provider | 1 call |
| `image_convert` | Convert, resize or compress an image, returns a hosted link | 1 call |
| `image_cdn_upload` | Host an image and get a delivery link | 1 call |
| `qr_barcode_generate` | QR, UPI QR or barcode image, returns a hosted link | 1 call |

The MCP server holds no keys of its own: every tool call is the same REST call made with your key and
counts against the same quota. Full reference: [`docs/mcp.md`](docs/mcp.md).

## Screenshots

<p align="center">
  <img src="assets/corenexis-api-dashboard.png" alt="Corenexis API dashboard - API marketplace" width="760">
</p>

## Links

- Website: https://api.corenexis.com
- MCP guide: https://api.corenexis.com/mcp
- Dashboard: https://dash.corenexis.com
- MCP health: https://api.corenexis.com/mcp/health
- Support: https://helpdesk.corenexis.com or support@corenexis.com

---

Built by [Corenexis](https://corenexis.com). This repository holds documentation and examples; the API
service is hosted by Corenexis. Examples are released under the [MIT License](LICENSE).