Muse Code for Open-Source Contributors
The Contributor pricing tier makes Meta's CLI agent a near-free option for OSS work — with the data-use tradeoff that is fine for public code.
Muse Code is Meta's CLI coding agent released 2026-08-05. Its Contributor pricing tier is priced to remove cost as a blocker for open-source contribution.
This page covers why Contributor fits OSS work, how to set it up, and the norms to follow when submitting AI-assisted PRs to public projects.
For non-OSS work, Contributor is not appropriate. See the muse-code-for-engineering-teams guide for team rollout patterns.
Why Contributor Fits OSS
Contributor tier is $0.10 per million input tokens and $0.20 per million output tokens — roughly 12x cheaper than Standard.
The tradeoff is that Meta uses prompts and outputs to improve their products. For OSS code that is public anyway, that tradeoff is essentially free.
A month of intensive OSS coding on Contributor tier usually lands under $5. Cost stops being a blocker.
- $0.10 input / $0.20 output per M tokens
- 12x cheaper than Standard
- OSS code is public — tradeoff is essentially free
- A month of intensive OSS work: under $5
Using Muse Code Contributor for open-source work and want to keep norms tight? Book a consult and we will help set the AI-assistance policy.
Book a ConsultationSetup for OSS Contributors
Install Muse Code with curl -fsSL https://dev.meta.ai/install.sh | bash. First run authenticates through the browser against a Meta developer account.
Configure the Contributor tier at the request level. Verify the tier config in the Meta developer portal before your first real session.
Persistent memory means you can resume a contribution the next day without re-loading context — useful for OSS work that spans multiple sessions.
- curl install + browser auth
- Configure Contributor tier explicitly
- Verify in Meta developer portal before first session
- Persistent memory for multi-day contributions
Norms for AI-Assisted OSS PRs
Disclose AI assistance in the PR description. Most modern OSS projects expect it and some require it.
Attach the event log or its relevant excerpt if the maintainer wants to see the reasoning chain. The full trace can be exported.
Review the change yourself before submitting. AI-assisted does not mean AI-approved — you are still the contributor of record.
- Disclose AI assistance in PR description
- Attach event log excerpt if maintainer asks
- Review the diff yourself
- You are the contributor of record
What Not to Do on Contributor Tier
Do not use Contributor for private repositories, client code, or anything under NDA. That is not what the tier is for.
Do not use Contributor for code that includes secrets, private keys, or PII. Meta uses those prompts to improve their products.
Do not blur the tier decision in a single project. If a repo is mostly OSS but has one private branch, that private branch stays on Standard.
- No private repos on Contributor
- No client code, no NDA work
- No secrets, keys, or PII
- Keep private branches on Standard
How to use Muse Code
You do not host Muse Code yourself — you use it through a tool, so "getting started" really means choosing the right one.
The fastest way to put Muse Code to work day to day is inside an AI IDE, and Cursor is the most popular — it supports it directly, so you can be working in minutes. Prefer a different editor? Windsurf, Zed, and GitHub Copilot drive these models too.
Frequently Asked Questions
- Yes — Contributor tier makes AI-assisted OSS work near-free (about $5/month for intensive use) and the code is public anyway, so the data-use tradeoff is essentially free.
- Configure it explicitly at request level and verify in the Meta developer portal before your first session. Do not assume default.
- Yes — most modern OSS projects expect disclosure and some require it. Attach the event log excerpt if the maintainer wants to see the reasoning chain.
- No. Private repos of any kind — even forks of public repos — should stay on Standard tier.
- Do not use Contributor. If credentials or PII touch the codebase at all, use Standard.
- Usually under $5 for intensive contribution work. Cost stops being a blocker at this tier.
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