Cosyra vs Crush: An Agentic Terminal on a Phone

Short answer. Cosyra vs Crush is two different shapes, not a head-to-head. Crush is Charm's terminal AI coding agent: a single Go binary, source-available under FSL-1.1-MIT, free to run, that talks to 20+ model providers. But it has no mobile app, so on a phone it only runs inside a terminal — Termux on Android, and nothing native on iOS. Cosyra is a hosted Ubuntu 24.04 container you reach from native iOS and Android apps, with Claude Code, Codex CLI, OpenCode, and Gemini CLI pre-installed, and Crush installs on top in one command. If you own a machine that stays on, run Crush. If the device in your hand is a phone, we think Cosyra is the better fit.

We wrote this after running both: Crush on a Linux laptop the way Charm intends, then the same kind of agent loop from a cloud container on a phone while standing on a train platform. Both are good. Only one of them runs when there is no laptop in front of you.

This post was written by the Cosyra team. We compared Cosyra against Crush based on hands-on testing of both — Crush on Linux, Cosyra on iPhone and Android — plus first-hand reads of the Crush GitHub repository via the GitHub API, its README, charm.land, and our internal Crush factsheet. Crush facts and version numbers were re-verified first-hand on 2026-06-30 (v0.81.0, 25,907 stars).

How do Cosyra and Crush compare feature by feature?

The core difference in Cosyra vs Crush is what you get for your money. Crush is free software you run on a machine you supply; Cosyra is the machine itself, hosted and reached from a phone. Crush is source-available and local; Cosyra is a closed-source hosted container. The table below lines them up on thirteen attributes as of 2026-06-30.

What actually happens when you try to run Crush on a phone?

On Android, it half-works and then fights you. Crush's README lists Android among supported systems, which is true in the narrow sense that the Go binary runs in a Linux userland. But the packaged install is rough. We followed the Termux path a developer took in GitHub issue #793: install Node, grab the Termux .deb, run dpkg -i, and watch it fail with a Read-only file system error because the package writes to the Android system root instead of Termux's sandboxed $PREFIX. The reconstruction below quotes that exact error.

The workaround is real: install Crush with npm install -g @charmland/crush after Node, or pull the prebuilt android-arm64 archive Charm now ships, and it runs. But you inherit every Termux trade-off — Android killing background sessions when you switch apps, ephemeral default storage, manual provisioning of Node and Git before Crush even starts. On iOS the story is shorter: there is no terminal that runs arbitrary Linux binaries, so there is no native Crush at all.

So the honest test is not "Crush on a phone vs Cosyra on a phone." The test is: you want the thing Crush gives you at a desk — a terminal agent that reads your code and edits files — while you are away from your machine. We did exactly that on an iPhone from a train platform. We opened the Cosyra iOS app, dropped into a full-screen Ubuntu shell, ran npm install -g @charmland/crush, exported a provider key, typed crush, described a change, and approved the diff. No home server to keep awake, no Termux read-only error, no $PREFIX archaeology. That is the part a cloud container reproduces.

Where does Crush beat Cosyra?

Crush is free, local, source-available, provider-flexible, and carries the best terminal UX in the business. We ship a product that competes for the same agentic-coding job, and Crush is still the better answer for several real situations. Here are five, each grounded in a first-hand source.

• It's free software. The Crush binary costs nothing; you pay only your model provider through BYOK. Cosyra's compute past the free hour and trial is a $29.99/month subscription for the hosted machine. If you already have a machine that stays on, Crush's price is hard to beat.
• Source-available and inspectable. Crush is FSL-1.1-MIT: you can read the Go source, build it yourself, and each release converts to MIT after two years. Cosyra's orchestration is closed-source SaaS on Azure. If reading the code matters to you, that is a point for Crush, not us.
• Twenty-plus providers with mid-session switching. Crush talks to Anthropic, OpenAI, Gemini, Groq, Bedrock, VertexAI, and custom OpenAI-compatible endpoints, and lets you swap models mid-conversation while keeping context. Our container is BYOK too, but you pick a CLI per agent rather than switching models inside one agent surface.
• LSP-grade code understanding and MCP. Crush reads your code through the Language Server Protocol for real structural context and connects to MCP servers over stdio, HTTP, and SSE. That is a genuinely strong agent core, and it runs the same whether you launch it on a laptop or inside our container.
• Charm's terminal polish. Crush comes from the Bubble Tea team, and it shows. The Hacker News thread on Crush is full of developers praising the interface. Local-first, offline-capable for the editing parts, and no vendor machine dependency: it is just a binary you control.

Where does Cosyra beat Crush?

Cosyra beats Crush on the one axis Crush does not contest: it runs on a phone with no home server. Add pre-installed agent CLIs, a persistent workspace that follows you across devices, and not having to supply or maintain a machine. These are different-shape strengths, so we are precise about each.

A real terminal on a phone, with Crush one command away

Cosyra gives you an interactive Ubuntu 24.04 shell from the iOS and Android apps. Crush's only phone path is Termux on Android, which fights you at install time (issue #793) and dies when Android reclaims the background session. In our container, npm install -g @charmland/crush just works, because it is a standard x86_64 Ubuntu box, not an Android userland. You get Crush plus the four CLIs we pre-install, all in one shell.

Claude Code, Codex CLI, OpenCode, and Gemini CLI pre-installed

On a fresh Cosyra container, four agent CLIs are already on the PATH. You export a provider key and type claude, or add Crush on top. We pre-install the standalone CLIs because setup friction is the main thing that kills agent-driven mobile coding; nobody wants to provision Node, Git, and a toolchain one-handed on a phone keyboard before the first prompt.

A persistent workspace that follows you across devices

Cosyra containers carry 30 GB of persistent storage and hibernate after 10 minutes idle, resuming in place on next open. The same container is reachable from your iPhone, your Android tablet, and the web: clone a repo on the couch, pick it up from the waiting room, finish at your desk, all in one shell. Crush is tied to whatever machine you installed it on; there is no hosted workspace that travels with you, and a Termux session that Android killed does not come back mid-thought.

You don't have to supply or maintain the machine

Crush needs a computer you own and keep running, or a Termux session you babysit. We run the machine for you. There is nothing to leave powered on at home and SSH back into; the container is the thing you connect to. For a developer whose only always-available device is a phone, that removes the biggest hidden dependency in every "run Crush remotely" workaround.

An opinion the Crush crowd would push back on

Here is where we disagree with the prevailing terminal-agent view. Charm's choice to ship a clean binary and let you run it wherever is the right call, and we admire it. But the assumption underneath most terminal-agent culture — that you obviously have a trusty local machine to run the binary on — is the part we think is dated. Plenty of people's primary computer is a phone. We think the phone keyboard is fine for agent-driven coding, because when the agent does the typing your job shrinks to prompt, review, and approve, and that fits a phone on a train fine. Most developers who scoff at coding from a phone have never actually driven an agent from a real shell on one. Crush's fans would likely say a terminal belongs on a machine you own; we built Cosyra because we don't think you should need to own and babysit one.

Who should pick Crush instead of Cosyra?

Pick Crush if you are a desktop-primary developer who wants a free, source-available terminal agent on a machine you already run, you value provider breadth and mid-session model switching, or you want to read and self-build your tooling. We run Crush ourselves on a laptop and Cosyra from our phones; they are not mutually exclusive, and Crush installs cleanly inside Cosyra when you want both.

Try Crush first if you are one of these profiles

• Desktop-primary developer. You code from a laptop or workstation 95% of the time. Crush's free binary and Charm UX make your daily terminal better in ways a mobile container does not try to. For this shape of use, Crush is the right answer, not us.
• Cost-sensitive and machine-rich. You already have a Linux box or Mac that stays on, and you would rather pay $0 for the tool and only your model bill. Crush plus your own hardware beats paying for a hosted container you do not need.
• Source-availability and provider flexibility matter most. You want to inspect the agent, self-build it, or hop across 20+ providers mid-session. Crush's FSL-1.1-MIT source and provider breadth are things Cosyra's closed orchestration does not match.

We use Crush when we are at a desk with a machine already running. We use Cosyra when the only device we have is a phone — and then we install Crush inside it. Different tools, different places. Choose by where you are, not by which is "better."

How do you try Cosyra if you're coming from Crush?

You try Cosyra from a Crush background in about two minutes: install from the App Store or Google Play, open the app, and you land in a fresh Ubuntu 24.04 x86_64 container with Claude Code, Codex CLI, OpenCode, and Gemini CLI already on PATH. The git and shell commands you run around Crush translate one-to-one; the difference is there is no read-only $PREFIX fight and no machine to keep powered on. If you want Crush specifically, one npm command puts it there.

If you wrap long Crush sessions so they survive interruptions, the Cosyra equivalent is tmux: start a named session, detach, and reattach after your phone locks or the connection drops — the thing a killed Termux session cannot do. We walk the full Crush-on-mobile flow in our guide to running Crush on your phone, and the broader setup in How to Run Claude Code on Your Phone. For the full map of mobile coding options, the AI coding agents on mobile pillar lays out every route. If your real comparison set is other terminal agents, the same shape shows up in OpenCode on your phone, Cosyra vs Kilo Code (whose CLI is built on the same OpenCode base), and Cosyra vs Termux, and the raw Android-userland trade-offs are in running a Linux container on Android.

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