Agents and MCP
Agents connect to Passa’s MCP server at https://mcp.example.com/mcp over HTTP, and sign in with OAuth 2.1. There are no API keys.
Signing in
- The agent finds Passa’s sign-in server from the MCP server’s metadata, and registers itself.
- Your browser opens the sign-in page. You enter your email and open the magic link Passa sends.
- The consent page names the app and where it will send you back. If you allow it, the agent gets a short-lived token for the MCP server only, and a refresh token that changes each time it’s used.
Connected apps are listed at auth. on your deployment’s domain, where you can revoke any of them. Only publishers — people the deployment’s admins have added — can connect.
Tools
| Tool | What it does |
|---|---|
publish |
Publishes files as a new site, private unless rules say otherwise |
update |
Changes a site: new or changed files, removals, small text edits, or a whole folder with sync |
begin_upload, finish_upload |
Uploads larger files, or files read from disk, straight to storage |
get_site |
A site’s details, versions and files |
get_files |
The contents of a site’s files |
find_sites |
Lists your sites, optionally matching a title or name |
set_access |
Replaces a site’s access rules |
set_name |
Gives a site a name, which becomes its address |
rollback |
Makes an earlier version current again |
delete |
Deletes a site |
theme_guide |
The theme guide, for writing themes and widgets |
Each tool’s description tells the agent what it needs to know: limits, how Markdown renders, and when to check with you.
Checks that don’t depend on the agent
The server enforces these, whatever the agent does:
- Making anything public needs
confirm_public, which the agent should only send after you agree. - Uploads are scanned for malware before they’re used.
- File types, sizes and paths are checked, and a site’s limits apply (by default 1,000 files, 25 MB per file and 100 MB per site).
- Every change is recorded with who made it.
Limits and history
A Markdown file and the page made from it count as one file. Every change makes a new version. Versions are kept for 30 days, then the last version of each month for 24 months, and the current version is always kept. A deleted site stops being served at once and is removed for good after seven days. A deployment can change these defaults.