MCP

One remote MCP server for every AI app, and the same server locally through the CLI. Sign-in is OAuth: the app registers itself, the person approves once.

The server

Server URL

https://mcp.sixteenbridges.com/mcp


Transport	Streamable HTTP, stateless: one JSON response per request, no sessions.
Protocol	2025-11-25
Sign-in	OAuth 2.1 with PKCE and dynamic client registration (below).
Tools	list, read, search, save, update, delete (to the trash), list the trash, restore, share, list shares.

Connect an app

Terminal agents add it with one command; their first use opens the browser to sign in.

Claude Code

Terminal

claude mcp add --transport http sixteen-bridges https://mcp.sixteenbridges.com/mcp

In Claude Code, run /mcp, pick sixteen-bridges and sign in. Allow it on sixteenbridges.com.

Codex

Terminal

codex mcp add sixteen-bridges --url https://mcp.sixteenbridges.com/mcp
codex mcp login sixteen-bridges

The login opens your browser: Allow it on sixteenbridges.com.

Gemini CLI

Terminal

gemini mcp add --transport http sixteen-bridges https://mcp.sixteenbridges.com/mcp

In Gemini CLI, run /mcp auth sixteen-bridges. Allow it on sixteenbridges.com.

Chat apps add it in their settings. Each app decides which of its plans can add a custom connector.

Claude (claude.ai, Desktop)

Open Settings → Connectors and choose Add custom connector.
Name it Sixteen Bridges and paste the URL: https://mcp.sixteenbridges.com/mcp
Choose Connect, then Allow on sixteenbridges.com.

Free plans can add one custom connector.

ChatGPT

Turn on Developer mode: Settings → Apps (or Connectors) → Advanced settings.
Create an app or connector named Sixteen Bridges with the URL https://mcp.sixteenbridges.com/mcp and OAuth sign-in.
Allow it on sixteenbridges.com, then turn it on in the chat.

Developer mode is on paid plans, and saving or editing bubbles from ChatGPT may need a Business or Enterprise plan. Workspace admins may need to allow custom apps first.

Gemini (gemini.google.com)

On a computer, open gemini.google.com → Settings → Connected Apps. If it isn't there, open Personal Intelligence first.
Under Custom apps, choose Add a custom app.
Paste the URL https://mcp.sixteenbridges.com/mcp and choose Next. Leave Advanced features empty: it signs in by itself.
Follow the prompts (name it Sixteen Bridges if asked), then Allow on sixteenbridges.com.
In a chat, type @ and pick Sixteen Bridges.

Custom apps are only for people 18 or over in the US, on a personal Google account (not work or school), in English, with Keep Activity on. Added on the web, they then work in the Gemini app too.

Grok

Open grok.com/connectors, choose New Connector, then Custom.
Paste the URL: https://mcp.sixteenbridges.com/mcp
Allow it on sixteenbridges.com.

Custom connectors are on paid Grok plans.

Perplexity

Open Settings → Connectors and choose Custom connector, Remote.
Name it Sixteen Bridges, paste the URL https://mcp.sixteenbridges.com/mcp, and choose OAuth.
Allow it on sixteenbridges.com, then turn it on under a thread's sources.

Custom connectors are on Pro, Max and Enterprise plans, and are added on the web.

MCP, locally

Desktop apps that start local MCP servers can run the CLI as one: the same tools, on the computer's own sign-in, with no connector and no paid plan. Sign in once first:

Terminal

npx sixteenbridges login

Claude Desktop

Settings → Developer → Edit Config (claude_desktop_config.json)

{
  "mcpServers": {
    "sixteen-bridges": {
      "command": "npx",
      "args": [
        "-y",
        "sixteenbridges",
        "mcp"
      ]
    }
  }
}

First, sign this computer in once: npx sixteenbridges login
Add this to the config file, save, and restart Claude Desktop.

On Windows, if it doesn't start, use "command": "cmd" with "args": ["/c", "npx", "-y", "sixteenbridges", "mcp"].

Cursor

~/.cursor/mcp.json

{
  "mcpServers": {
    "sixteen-bridges": {
      "command": "npx",
      "args": [
        "-y",
        "sixteenbridges",
        "mcp"
      ]
    }
  }
}

First, sign this computer in once: npx sixteenbridges login
Add this to ~/.cursor/mcp.json (or Settings → MCP → Add), then reload.

VS Code

.vscode/mcp.json

{
  "servers": {
    "sixteen-bridges": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "sixteenbridges",
        "mcp"
      ]
    }
  }
}

First, sign this computer in once: npx sixteenbridges login
Add this to .vscode/mcp.json in your project (or your user MCP settings), then start the server.

Windsurf

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "sixteen-bridges": {
      "command": "npx",
      "args": [
        "-y",
        "sixteenbridges",
        "mcp"
      ]
    }
  }
}

First, sign this computer in once: npx sixteenbridges login
Add this to ~/.codeium/windsurf/mcp_config.json, then refresh its MCP servers.

How clients sign in

MCP clients do all of this by themselves; it is here for anyone building one, and to show what happens.

The server says where to sign in

A request without a token gets 401, naming the resource's metadata (RFC 9728):

HTTP

POST /mcp HTTP/1.1
Host: mcp.sixteenbridges.com

HTTP/2 401
www-authenticate: Bearer resource_metadata="https://mcp.sixteenbridges.com/.well-known/oauth-protected-resource/mcp"

The metadata names the authorization server

curl https://api.sixteenbridges.com/.well-known/oauth-protected-resource
# → "authorization_servers": ["https://lhoaehepgmmqlltutgos.supabase.co/auth/v1"]

curl https://lhoaehepgmmqlltutgos.supabase.co/auth/v1/.well-known/oauth-authorization-server

Response

{
  "issuer": "https://lhoaehepgmmqlltutgos.supabase.co/auth/v1",
  "authorization_endpoint": "https://lhoaehepgmmqlltutgos.supabase.co/auth/v1/oauth/authorize",
  "token_endpoint": "https://lhoaehepgmmqlltutgos.supabase.co/auth/v1/oauth/token",
  "registration_endpoint": "https://lhoaehepgmmqlltutgos.supabase.co/auth/v1/oauth/clients/register",
  "code_challenge_methods_supported": ["S256", "plain"],
  "grant_types_supported": ["authorization_code", "refresh_token"]
}

The client registers, the person approves, the code becomes tokens
Dynamic client registration, then the authorization code flow with PKCE (S256), exactly as in the REST API's sign-in. The person sees one question on sixteenbridges.com: allow this app to use your bubbles?
Every request carries the token
Authorization: Bearer <access token>. Only tokens issued to an app this way are accepted, not a website session. When it expires, the client renews it with the refresh token.

Disconnecting an app on the account page ends its access within a minute. Its next request gets 401, and it has to ask the person again.

Tools

Results are compact text written for a model: ids, titles, sources, sizes, dates, one-line previews.

`list_bubbles`read-only

The bubbles, newest first: id, title, source, size, date and a one-line preview, plus how much of the allowance is used.

Parameters
`query`string	Words to search for in titles and contents (2–100 characters).
`limit`integer	How many, 1–50 (default 20).
`cursor`string	The next page, from the reply's More: line.

`get_bubble`read-only

One bubble: a short header, then its Markdown. Long ones come in pages of 30,000 characters; the reply ends with the offset to read next.

Parameters
`id`string · required	From list_bubbles.
`offset`integer	The character to start from (default 0).
`max_chars`integer	Characters per page, 1,000–100,000 (default 30,000).

`save_bubble`writes

Saves new context as a bubble and answers with its id.

Parameters
`title`string · required	Short and specific, up to 120 characters.
`content`string · required	Markdown.
`source`string	The app saving it: claude, chatgpt, gemini, grok, perplexity, api or other (default api).
`label`string	Where it came from, e.g. the chat's name.

`update_bubble`writes

Renames a bubble, replaces its content, or adds to its end without sending it all again.

Parameters
`id`string · required	From list_bubbles.
`title`string	A new title.
`content`string	New content, replacing all of it.
`append`string	Text to add at the end, after a blank line.

`delete_bubble`destructive

Moves a bubble to the trash: restorable for 7 days, then deleted for good.

Parameters
`id`string · required	From list_bubbles.

`list_deleted_bubbles`read-only

What is in the trash, and until when each can be restored.

`restore_bubble`writes

Brings a bubble back from the trash.

Parameters
`id`string · required	From list_deleted_bubbles.

`share_bubbles`sends to someone

Sends copies of bubbles to another Sixteen Bridges account, by email. All arrive or none do; a full account is refused.

Parameters
`email`string · required	The receiver's email, exactly as the user gave it.
`bubble_ids`string[] · required	1–20 ids, from list_bubbles.

`list_shares`read-only

What was shared and received, newest first: with whom, which bubbles (with ids), and which received ones are new.

Parameters
`direction`string	sent or received (default both).
`cursor`string	The next page, from the reply's More: line.

Resources and prompts

Resources and prompts
`bubble://{id}`resource	A bubble as Markdown, listed and readable, for apps that attach resources (@-mentions).
`use_bubble`prompt	Brings a bubble into the chat as context: give an id or words from its title.

Calling it directly

It is plain JSON-RPC over HTTP, with a token from the sign-in above:

curl

curl https://mcp.sixteenbridges.com/mcp \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "MCP-Protocol-Version: 2025-11-25" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"list_bubbles","arguments":{"limit":5}}}'

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "content": [{
      "type": "text",
      "text": "1 of 20 bubbles used, up to 512 KB each.\n1. [bub_0195f3a2-…] Lisbon trip · Claude · Trip chat · 27 B · 2026-10-27\n   # Day 1 Trams, then Sintra."
    }]
  }
}

MCP

The server

Connect an app

Claude Code

Codex

Gemini CLI

Claude (claude.ai, Desktop)

ChatGPT

Gemini (gemini.google.com)

Grok

Perplexity

MCP, locally

Claude Desktop

Cursor

VS Code

Windsurf

How clients sign in

Tools

list_bubblesread-only

get_bubbleread-only

save_bubblewrites

update_bubblewrites

delete_bubbledestructive

list_deleted_bubblesread-only

restore_bubblewrites

share_bubblessends to someone

list_sharesread-only

Resources and prompts

Calling it directly

`list_bubbles`read-only

`get_bubble`read-only

`save_bubble`writes

`update_bubble`writes

`delete_bubble`destructive

`list_deleted_bubbles`read-only

`restore_bubble`writes

`share_bubbles`sends to someone

`list_shares`read-only