Composer

What Composer is

Composer is a web-based, real-time Markdown editor for people and AI agents to work together on documents. Teammates and agents can collaborate in shared documents, with agents connecting over MCP; changes sync across teammates, devices, and sessions. Documents use plain Markdown and can be exported as Markdown. The listed publishing workflow is none. The free plan includes unlimited public documents and collaborators, plus up to 7 private documents, 3 collaborators per private document, and a 10 MB upload limit. Pro removes the free-plan limits on private documents and collaborators and includes early access to new features. Pro costs $7.99 a month billed monthly, or $5.99 a month billed annually at $71.88 a year. Users can cancel anytime, with the plan active through the paid period. Checkout is handled by Stripe.

Who it suits

Composer suits people and teams who want to edit Markdown documents together with collaborators or AI agents. Its free plan may fit users working within the stated private-document and upload limits.

Limits

The free plan allows up to seven private documents, three collaborators per private document and 10 MB uploads. Pro removes the private-document and collaborator limits; it includes early access to new features.

Getting started

1. Open Composer at https://usecomposer.md/.
2. Choose the Free plan or a Pro plan.
3. Create public documents for unlimited collaborators, or use private documents within the Free plan limits.
4. Invite collaborators to a private document, up to three on the Free plan.
5. Connect an AI agent over MCP to let it join a document as a collaborator.
6. Export Markdown when you need to use the document in another editor.

Verdict

Composer combines shared Markdown editing with agent collaboration over MCP. The free plan has specific private-document and upload limits; Pro removes private-document and collaborator limits for the listed prices.