Comparison

Helicon vs OpenCode

Q: Do I need API keys for Helicon?

No. Authentication is your own `muse login`, held by the CLI. Helicon never stores credentials.

OpenCode is an open-source agent harness that you point at providers, usually with its own API billing. Helicon is not a harness at all: it is a desktop and web interface for Meta's Muse Code CLI, so the agent, the models and the subscription are the ones you already have, with no second route to pay for.

Last updated 17 October 2026 · Markdown version

At a glance

	Helicon	OpenCode	Checked
What it is	GUI client for the Muse Code CLI	Open source AI coding agent	17 October 2026
Agent	Muse Code	Its own loop over chosen providers	17 October 2026
Billing	Existing Muse Code subscription	Usually your own API keys	17 October 2026
Interface	Desktop app and web UI	Terminal, desktop app or IDE extension	17 October 2026
Session list across repos	Yes	Lists all sessions	17 October 2026
License	MIT	Open source	17 October 2026
Approvals	Muse Code's own, surfaced one to one	Harness defined	17 October 2026

Helicon compared with OpenCode. The Checked column links the docs or changelog page behind each sourced row.

What each one is

OpenCode is a good answer to a different question: how do I get an open agent loop that I control end to end, across whichever providers I like. That control comes with provider configuration and, for most people, pay as you go API billing.

Helicon does not try to own the loop. Muse Code owns the loop. Helicon is the window: sessions grouped by working directory, resume, inline diffs, an approval queue, and what each thread would have cost at published rates.

Where they actually differ

Subscription reuse is the point

A recurring complaint from people who buy a coding subscription is finding that a favourite harness routes through its own API metering instead. Helicon uses your muse login and nothing else, so the plan you bought is the plan that pays.

Whose loop it is

OpenCode runs in a terminal, a desktop app or an IDE extension, and in each one the loop is its own. Helicon is a window onto Muse Code's loop, with persistent history, cross project triage and a cost surface.

Protocol native

Helicon speaks the Muse Code Session Protocol through Meta's MIT SDK rather than scraping a TUI, so sessions started from the terminal are discovered and resumable.

Choose OpenCode if

You want to choose and mix providers yourself.
You are happy in a terminal and want maximum control over the agent loop.
You need an agent where no vendor CLI is involved.

Choose Helicon if

Your subscription is Muse Code and you want it to be the thing that pays.
You want a GUI with history, diffs, approvals and cost.
You want sessions started in the muse TUI to be visible and resumable.

Can you use both?

They are not exclusive, but they are not complementary either: one is a harness, the other is a client for a different harness. Pick by whether your Muse Code plan should be doing the work.

Helicon is one Muse Code GUI of several, and that page lists the rest. Helicon is free and MIT licensed, and you can try Helicon in your browser on sample data before you install anything.