yojimbo VS Cap'n Proto

Compare yojimbo vs Cap'n Proto and see what are their differences.

yojimbo

A network library for client/server games written in C++ (by mas-bandwidth)

Cap'n Proto

Cap'n Proto serialization/RPC system - core tools and C++ library (by capnproto)
Stream - Scalable APIs for Chat, Feeds, Moderation, & Video.
Stream helps developers build engaging apps that scale to millions with performant and flexible Chat, Feeds, Moderation, and Video APIs and SDKs powered by a global edge network and enterprise-grade infrastructure.
getstream.io
featured
InfluxDB – Built for High-Performance Time Series Workloads
InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.
www.influxdata.com
featured
yojimbo Cap'n Proto
5 74
2,586 12,278
0.4% 0.7%
6.8 9.1
19 days ago 6 days ago
C C++
BSD 3-clause "New" or "Revised" License GNU General Public License v3.0 or later
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.

yojimbo

Posts with mentions or reviews of yojimbo. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-10-06.

Cap'n Proto

Posts with mentions or reviews of Cap'n Proto. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2025-06-27.
  • Rust in the Linux kernel: part 2
    4 projects | news.ycombinator.com | 27 Jun 2025
    My interest in Rust comes from getting frustrated with C's type system. Rust has such a nice type system and I really enjoy the ownership semantics around concurrency. I think that C++ written "correctly" looks a lot like Rust and libkj [1] encourages this, but it is not enforced by the language.

    [1] https://github.com/capnproto/capnproto/blob/v2/kjdoc/tour.md

  • Writing your own C++ standard library part 2
    5 projects | news.ycombinator.com | 1 Jun 2025
    Have you seen libkj [1]? I've used it and really enjoy working with it. It has a rust-like owned pointer and the whole library uses these smart pointers.

    It has proper container classes based on B-trees and its also got an async runtime.

    [1] https://github.com/capnproto/capnproto/blob/v2/kjdoc/index.m...

  • The first year of free-threaded Python – Labs
    3 projects | news.ycombinator.com | 16 May 2025
  • Ask HN: Which Opens Source Software have the sexiest code?
    1 project | news.ycombinator.com | 5 Apr 2025
  • Begrudgingly Choosing CBOR over MessagePack
    2 projects | news.ycombinator.com | 2 Mar 2025
    Just curious if you considered Cap'n Proto as another option, or if it wasn't in the running?

    [1] https://capnproto.org/

  • Cap'n Proto: High-Performance Serialization and RPC for Modern C++
    1 project | news.ycombinator.com | 11 Aug 2024
  • The Simdjson Library
    4 projects | news.ycombinator.com | 3 Jun 2024
  • Demystifying the Protobuf Wire Format
    4 projects | news.ycombinator.com | 17 May 2024
    To be fair, if that's what you need ProtoBuf isn't the only option. Cap'n Proto[1], JSON Schema[2], or any other well supported message-definition language could probably achieve that as well, each with their own positives and negatives.

    [1]: https://capnproto.org/

    [2]: https://json-schema.org/

  • Mysterious Moving Pointers
    1 project | news.ycombinator.com | 14 Apr 2024
    Yeah I pretty much only use my own alternate container implementations (from KJ[0]), which avoid these footguns, but the result is everyone complains our project is written in Kenton-Language rather than C++ and there's no Stack Overflow for it and we can't hire engineers who know how to write it... oops.

    [0] https://github.com/capnproto/capnproto/blob/v2/kjdoc/tour.md

  • Show HN: Comprehensive inter-process communication (IPC) toolkit in modern C++
    2 projects | news.ycombinator.com | 9 Apr 2024
    - may massively reduce the latency involved.

    Those sharing Cap'n Proto-encoded data may have particular interest. Cap'n Proto (https://capnproto.org) is fantastic at its core task - in-place serialization with zero-copy - and we wanted to make the IPC (inter-process communication) involving capnp-serialized messages be zero-copy, end-to-end.

    That said, we paid equal attention to other varieties of payload; it's not limited to capnp-encoded messages. For example there is painless (<-- I hope!) zero-copy transmission of arbitrary combinations of STL-compliant native C++ data structures.

    To help determine whether Flow-IPC is relevant to you we wrote an intro blog post. It works through an example, summarizes the available features, and has some performance results. https://www.linode.com/blog/open-source/flow-ipc-introductio...

    Of course there's nothing wrong with going straight to the GitHub link and getting into the README and docs.

    Currently Flow-IPC is for Linux. (macOS/ARM64 and Windows support could follow soon, depending on demand/contributions.)

What are some alternatives?

When comparing yojimbo and Cap'n Proto you can also consider the following projects:

ENet-CSharp - Reliable UDP networking library

gRPC - C++ based gRPC (C++, Python, Ruby, Objective-C, PHP, C#)

bitproto - The bit level data interchange format for serializing data structures (long term maintenance).

ZeroMQ - ZeroMQ core engine in C++, implements ZMTP/3.1

netcode.io - Secure client/server connections over UDP

FlatBuffers - FlatBuffers: Memory Efficient Serialization Library

Stream - Scalable APIs for Chat, Feeds, Moderation, & Video.
Stream helps developers build engaging apps that scale to millions with performant and flexible Chat, Feeds, Moderation, and Video APIs and SDKs powered by a global edge network and enterprise-grade infrastructure.
getstream.io
featured
InfluxDB – Built for High-Performance Time Series Workloads
InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.
www.influxdata.com
featured