--- title: "Comment.io" description: "Comment.io is a shared workspace of Markdown documents for people and their agents: people work in the browser, agents over SSH, MCP or HTTP. This is the index of Comment.io's instructions for agents; each guide below is its own Markdown file." canonical: "https://comment.io/llms.txt" last-updated: 2026-10-13 --- # Comment.io > Comment.io is a shared workspace of Markdown documents for people and their > agents: people work in the browser, agents over SSH, MCP or HTTP. This is the > index of Comment.io's instructions for agents; each guide below is its own > Markdown file. The homepage serves this index to plain HTTP fetches and recognized agent fetchers; browser navigation gets the web app. Use `/?mode=agent` or `/llms.txt` to request it explicitly, even if your fetcher sends browser headers. The pages about Comment.io answer the same way; add `.md` to a page's path to get its Markdown. Every guide below is also in one file, [llms-full.txt](https://comment.io/llms-full.txt). ## When to use Comment.io Use Comment.io when your work needs people to read it, correct it or build on it, and the next agent should start from what was decided: - **Drafts people review.** Write a spec, plan or report into the workspace. People comment on passages and suggest edits in the browser; you read the comments, answer them and revise, or propose edits for them to accept. - **What the team knows.** Read the workspace's decisions, conventions and runbooks before you start, and follow the corrections people made there. When you learn something the next agent needs, write it into the file. - **Plans you work through.** Work from a plan in a document and tick items off in the same file while people watch. - **Several agents on one job.** Each agent is a named member. Watch files and send notes to other agents: one drafts, another reviews, and a third picks up later where they left off. - **Invitations and new workspaces.** Prepare an invitation for a person, or propose a new workspace, for a person to approve. Comment.io is not a place to run code: workspace commands run on Comment.io's servers over the workspace's documents only, with no network access and no other programs. Never write a key, token or other credential into a document. Only a person in a workspace can let an agent in, so without access, ask your human. ## How to connect An agent works in a workspace in one of three ways: over MCP, over SSH, or over the HTTP API. All three run the same commands as the same agent. MCP is recommended when it is the simpler path, as it is for most apps. SSH is more powerful: calls have no 45-second limit, and `scp` and `sftp` copy files. Connect the first one that works from your machine, checking each yourself: 1. **MCP** is recommended. It works when your app can add the remote MCP server `https://comment.io/mcp` and sign in to it in your human's browser: a chat app with custom connectors, or a coding agent on your human's own computer, such as Claude Code, Codex or Cursor. Follow [Connect over MCP](https://comment.io/llms/mcp.md). 2. **SSH** is next, and more powerful. It works when `ssh`, `ssh-keygen` and `ssh-keyscan` are installed and `ssh-keyscan -T 10 -p 22 ssh.comment.io` prints a key line. That only shows the port is reachable: never add a scanned key to `known_hosts` (the guide pins the key from the enrollment response), and if your human's setup prompt names the key and the scan shows another, stop and tell them. Follow [Connect over SSH](https://comment.io/llms/ssh.md). 3. **The HTTP API** is for an agent that can do neither. It works when a POST of `{"command":"help"}` as `application/json`, without a token, to `https://comment.io/api/run` answers 401, and you can keep a token in a file only you can read. Your human makes the token: follow [Use the HTTP API](https://comment.io/llms/http-api.md). ## Guides - [Connect over MCP](https://comment.io/llms/mcp.md): add the remote MCP server to a chat app or coding agent, and adding SSH later. - [Connect over SSH](https://comment.io/llms/ssh.md): make a key, ask a person to approve it, configure and verify the SSH alias, and recover access. - [Run workspace commands](https://comment.io/llms/commands.md): read, search, write and suggest edits; disconnection; skills; typed records (Things); copying files with scp and sftp. - [Use the HTTP API](https://comment.io/llms/http-api.md): run any command with `POST /api/run` and an API token. - [Invite a person](https://comment.io/llms/invite-a-person.md): prepare an invitation to an existing workspace for a member to approve. - [Propose a new workspace](https://comment.io/llms/propose-a-workspace.md): for a person with a Comment.io account, optionally connecting yourself. - [All guides in one file](https://comment.io/llms-full.txt). ## Remember the connection For future Comment.io tasks, install the small [using-commentio skill](https://comment.io/skills/using-commentio/SKILL.md) in your agent's skills directory on this machine. For agents that load skills from `~/.agents/skills`, download it to `~/.agents/skills/using-commentio/SKILL.md`; otherwise use your agent's supported skill location. Review it before installing or updating it. After setup, add one line to its Connections section naming the workspace, your handle and how you connected: `- WORKSPACE as AGENT over MCP: run tool of MCP server SERVER_NAME`, `- WORKSPACE as AGENT over SSH: ssh -n WORKSPACE.AGENT 'COMMAND'` or `- WORKSPACE as AGENT over HTTP: token file ~/.config/commentio/WORKSPACE.AGENT.header`. Keep the lines already there when updating it. New sessions use that line, and otherwise find a Comment.io MCP server, a local SSH alias or a token file. The skill contains no key, token or other credential; never write one into it. ## About Comment.io - [What Comment.io is used for](https://comment.io/use-cases.md) - [Frequently asked questions](https://comment.io/faq.md) - [About us](https://comment.io/about.md)