Composer
Composer is a real-time Markdown editor for people and AI agents to work on shared documents.
What Composer is
Composer is a real-time Markdown editor for people and AI agents to work on shared documents. Agents connect over MCP and can join as collaborators, with the standard allowing them to read from and write to Composer documents. Changes sync across teammates, devices, and sessions. Documents use plain Markdown, so they remain readable in other editors, and the web app supports Markdown export. The listed publishing workflow is none. The free plan allows 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 private-document and collaborator limits and includes early access to new features. Pro Monthly is $7.99 a month, billed monthly at $7.99 per user. Pro Annual is $5.99 a month, billed annually at $71.88 a year. Users can cancel anytime and keep the plan active through the paid period. Checkout is handled by Stripe.
Good
- Real-time collaboration supports people and agents.
- MCP agents can read and write shared documents.
- Changes sync across teammates, devices, and sessions.
- Plain Markdown stays readable in other editors.
Watch out
- Free plan limits private documents to seven.
- Free private documents allow three collaborators each.
- Free plan upload limit is 10 MB.
- No publishing workflow is listed.
Who it suits
Composer suits teams that want to edit Markdown documents together with people and AI agents. The free plan may fit users with modest private-document and upload needs, while Pro removes the listed private-document and collaborator limits.
Verdict
Composer centers on shared Markdown editing, including agent participation through MCP. Consider its private-document and upload limits, and choose the listed Pro billing term if those limits are restrictive.
Plans and prices
From Composer's own pricing page, checked 28 Sep 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Up to 7 private documents, 3 collaborators per private document, and a 10 MB upload limit. · 7 private documents · 3 collaborators per private document · 10 MB upload limit |
| Pro | $7.99 a month | Unlimited private documents · Unlimited private-document collaborators · Early access to new features · billed monthly |
| Pro Annual | $5.99 a month | Removes free-plan limits on private documents and collaborators. · billed annually at $71.88 per year |
| Pro Monthly | $7.99 a month | Removes free-plan limits on private documents and collaborators. · billed monthly at $7.99 per user |
The facts
Each one read from Composer's own pages, with the date it was checked.
What it does
- Agent Collaboration
- Agents join documents as true collaborators.checked 28 Sep 2026
- Agent Connection
- AI agents connect to Composer over MCP.checked 28 Sep 2026
- Cancellation Policy
- Users can cancel anytime, with the plan active through the paid period.checked 28 Sep 2026
- Change Sync
- Changes sync across teammates, devices, and sessions.checked 28 Sep 2026
- Cloud sync
- Yeschecked 20 Sep 2026
- Early Feature Access
- Pro includes early access to new features.checked 28 Sep 2026
- Editor Type
- Composer is a real-time, multiplayer Markdown editor for people and agents.checked 28 Sep 2026
- Export formats
- Markdownchecked 20 Sep 2026
- Markdown Compatibility
- Composer uses plain Markdown, keeping documents readable in other editors.checked 28 Sep 2026
- MCP Standard
- MCP lets agents read from and write to shared Composer documents.checked 28 Sep 2026
- Private Documents
- The free plan allows up to 7 private documents.checked 28 Sep 2026
- Pro Private Limits
- Pro makes private documents and collaborators unlimited.checked 28 Sep 2026
- Public Documents
- Free users get unlimited public documents and collaborators.checked 28 Sep 2026
- Publishing workflow
- nonechecked 20 Sep 2026
- Real-time collaboration
- Yeschecked 20 Sep 2026
- Upload Limit
- The free plan has a 10 MB upload limit.checked 28 Sep 2026
Money
- Billing Provider
- Checkout is handled by Stripe.checked 28 Sep 2026
- Free Collaborators
- Each free private document supports up to 3 collaborators.checked 28 Sep 2026
- Free plan
- Yeschecked 20 Sep 2026
- Free Plan
- Composer offers a free plan to get started.checked 28 Sep 2026
Where it runs
- Supported platforms
- webchecked 20 Sep 2026
