Transfer files between machines through the web, through a CLI, or both.

Usage

Goto https://e2ecp.com and enter a room. Have another peer enter the same room to transfer files between the two.

Command-line Interface

Optionally, you can also transfer files via the command-line between machines (through website or direct CLI-to-CLI).

Either download the latest release or install with:

curl https://e2ecp.com | bash

Or build from source with make server.

Then you can also send and receive files from the command-line between other command-line users or users on the web interface.

Sending a file:

e2ecp send <file>

Receiving a file:

e2ecp receive

Run your own relay server

You can run your own relay server if you want to self-host.

e2ecp serve --port 8080

About

This project is created and maintained by Zack. If you find it useful, please consider sponsoring me on GitHub Sponsors.

It works by using a simple peer-to-peer connection through a knowledge-free websocket-based relay server. All data transferred is encrypted using end-to-end encryption with ECDH P-256 key exchange and AES-GCM authenticated encryption, meaning the relay server does not have access to the data being transferred.

Reliability Features

e2ecp implements several features to ensure reliable file transfers:

• Chunk Acknowledgments: Each data chunk is acknowledged by the receiver
• Automatic Retransmission: Lost chunks are automatically retried (up to 3 attempts)
• Chunk Ordering: Out-of-order chunks are buffered and reordered correctly
• Timeout Detection: Transfers that stall for 30+ seconds are automatically aborted
• Hash Verification: File integrity is verified using SHA-256 checksums
• Thread-Safe: Concurrent operations are protected with mutexes

These features ensure that transfers complete successfully even over unreliable network connections.

Testing

e2ecp includes comprehensive test suites to ensure reliability:

Unit and Integration Tests

Run Go tests for the core functionality:

go test -v ./...

End-to-End Tests

Playwright tests verify web-to-web and web-to-CLI file transfers:

cd tests
./run-tests.sh

See tests/README.md for detailed testing documentation.

License

MIT — see LICENSE.