Cptn.io - Open-Source Integration and Data Platform

TL;DR

TL;DR: Cptn.io is an open-source, self-hostable integration and ETL platform. Build pipelines visually, schedule batch jobs, deploy via Docker, and extend with community-contributed apps — all under MIT license.

Source and Accuracy Notes

This section is MANDATORY. All links must be verified from actual source, not guessed.

• Project page: cptn.io — verified 2026-06-23
• Source repository: github.com/cptn-io/el-cptn — verified 2026-06-23
• License: MIT — verified via README
• Documentation: docs.cptn.io — verified 2026-06-23
• HN launch thread: news.ycombinator.com/item?id=35864661 — 139 points
• GitHub stars: 493 (as of 2026-06-23, verified via GitHub API)
• Copyright: DevRaven Inc.

What Is Cptn.io?

Cptn.io (pronounced “captain.io”) is an open-source integration and data platform for building, deploying, and managing ETL pipelines and data integrations. It is designed to run self-hosted on your own infrastructure via Docker.

The platform targets developers and teams who want the pipeline-building capability of a commercial iPaaS without the vendor lock-in. It competes with tools like n8n, Apache NiFi, and Airflow for self-hosted use cases.

From the README:

“cptn.io is an open-source self-hostable platform that helps develop and deploy integrations and data pipelines quickly and easily.”

Key capabilities:

• Visual pipeline builder — design integrations via a web UI without writing boilerplate
• Scheduled batch processing — trigger pipelines on cron-like schedules
• Ready-to-use apps — community-contributed connectors for common transformations and destinations, auto-downloaded at runtime
• SSO support — single sign-on under MIT license
• Self-hosted only — no cloud SaaS offering; runs on your own Docker infrastructure

Setup Workflow

Prerequisites

• Docker and Docker Compose installed
• A server with a domain or static IP (optional for custom domain + SSL)

Step 1: Clone the repository

git clone -b stable https://github.com/cptn-io/el-cptn.git
cd el-cptn

Step 2: Configure environment

Copy the example env file and set your secrets:

cp .env.example .env
# Edit .env — set complex random passwords and secrets

Default credentials are provided for first-run only:

Username: [email protected]
Password: bar

Create a new user and disable the default credentials after first login.

Step 3: Start with Docker Compose

docker compose up

The required images are downloaded automatically. The platform starts within a few minutes.

Step 4: Access the web UI

Open http://localhost/ (or your server IP if remote). The web UI handles pipeline design, monitoring, and configuration.

Optional: Custom domain with auto-SSL

On a server with a public IP, set APP_URL to your domain in .env, run docker compose restart, and Caddy automatically provisions an SSL certificate.

Architecture

The stack (verified from README):

| Component | Technology | |---|---| | Backend | Spring Boot | | Processor | Node.js | | Web UI | React | | Reverse proxy | Caddy | | Database | PostgreSQL | | Cache | Redis |

Practical Evaluation Checklist

• Self-hosted via Docker — no cloud tier or vendor dependency
• MIT license — freely usable in commercial projects
• Visual pipeline builder — no code required for standard integrations
• Scheduled batch jobs — cron-like trigger support
• Community apps — auto-downloaded connectors, modifiable as plain scripts
• SSO available under MIT license
• No native Windows installer — Docker/Linux only
• No managed cloud offering — fully self-hosted
• Processor runs Node.js — pipeline scripts use JavaScript

Comparison with n8n

| | Cptn.io | n8n | |---|---|---| | License | MIT | Multiple (Fair-code) | | Cloud SaaS | No | Yes (extra cost) | | Community apps | Yes (auto-download) | Yes | | Self-hosted | Yes (Docker) | Yes (Docker) | | Batch scheduling | Yes | Via workflows | | License cost | Free | Free tier / paid plans |

Security Notes

• Default credentials must be changed on first use
• All pipeline data stays on your own infrastructure
• Secrets managed via environment variables (not hardcoded)
• SSO available as an open-source feature

FAQ

Q: Is there a hosted or cloud version of Cptn.io? A: No. Cptn.io is self-hosted only. There is no commercial SaaS or cloud offering — you deploy it on your own infrastructure.

Q: How does it differ from n8n? A: Both are visual workflow builders, but Cptn.io uses a batch-processing model with scheduled pipelines, while n8n focuses on event-driven workflows. Cptn.io is MIT-licensed with no commercial license restrictions.

Q: What programming language are pipeline scripts written in? A: The processor runs Node.js. Community apps are plain JavaScript scripts that you can modify to fit your requirements.

Q: Can I extend Cptn.io with custom connectors? A: Yes. The platform supports community-contributed “apps” that can be modified or created from scratch. See the apps contribution guide.

Q: Does it support Windows? A: The recommended deployment is Docker on Linux. Windows users can run it via Docker Desktop or WSL2.

Conclusion

Cptn.io fills a specific gap in the self-hosted integration space: a visual pipeline builder with batch scheduling, community apps, and a permissive MIT license — with no commercial upsell or vendor lock-in.

For teams already running n8n or Airflow, Cptn.io is worth evaluating as a lighter-weight alternative with a different execution model. For teams evaluating commercial iPaaS tools, it offers a zero-cost path to self-hosting the same core functionality.

Deploy it with docker compose up at cptn.io.