Second Brain Bridge

Name: Second Brain Bridge
Author: IsaiahDupree

by IsaiahDupreeversion 1.3.0i★ –iRuns in the cloud

Registry nameio.github.IsaiahDupree/second-brain-bridge

Install

Overview

Description from the maker (original English)

Search and reason over your Obsidian-style Markdown vault, right from ChatGPT.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiVery new★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs in the cloud
Transport: Streamable HTTP
Category: Docs, sheets & office work

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
The registry lists no key to fill in.

You need

Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://secondbrainbridge.vercel.app/mcp

Run this in your terminal

claude mcp add --transport http second-brain-bridge https://secondbrainbridge.vercel.app/mcp

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "second-brain-bridge": {
      "url": "https://secondbrainbridge.vercel.app/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "second-brain-bridge": {
      "type": "http",
      "url": "https://secondbrainbridge.vercel.app/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://secondbrainbridge.vercel.app/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 8, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account IsaiahDupree, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Docs, sheets & office worki

More stars than 0% of the other 3590 servers in this category
Published to the registry more recently than 21% of the other 3590 servers in this category
Basic checks equal to or better than 100% of the other 3590 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Second Brain Bridge safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.3.0) reached the registry 3 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Agent-Native Calendar, Excel MCP Server, MCP Server for Excel

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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Runs in the cloud

Install

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by haris-musaWidely used↓ 49.6K/wk★ 4.3KUpdated 8 days ago

Runs on your computer

Install

MCP Server for Excel

Excel automation for AI - Sheets, Power Query, DAX, VBA, Tables, Ranges and more. Windows only.

by sbroenneGrowing↓ 4.3K/wk★ 847Updated 5 days ago

Runs on your computer

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

🧠 SecondBrainBridge

Your Obsidian vault, searchable and reasoned over — inside ChatGPT, from your own Mac.

SecondBrainBridge is a Model Context Protocol (MCP) connector that lets ChatGPT search and reason over your Obsidian-style Markdown vault — a folder of notes on your Mac. Reads execute locally and requested results pass through the authenticated relay — every action runs on your own Mac through a tiny local agent. The cloud piece is only a stateless relay that shuttles requests between ChatGPT and your Mac.

  ChatGPT  ──OAuth──►  SecondBrainBridge relay  ──job queue──►  second-brain-agent  ──►  Obsidian vault

(connector) (Vercel, stateless) (your Mac, polls & executes) (Markdown notes on your Mac)

Your Mac is the only place your notes are ever read or written. The relay stores only short-lived job payloads and your account record; it never sees note content unless a job is in flight, and jobs expire in seconds.

For users — 3 steps

1. Create your account at [secondbrainbridge.vercel.app](https://secondbrainbridge.vercel.app) and generate a pairing code.

2. Install the Mac agent (needs Node 18+):

npx second-brain-agent pair <YOUR-CODE>   # link this Mac to your account

npx second-brain-agent install # keep it running on every restart

Point it at your vault folder — set SECONDBRAIN_VAULT=/path/to/your/vault, or save the path in ~/.secondbrainbridge-agent.json. The first time the agent reads a vault kept in a protected location (Documents, Desktop, or iCloud Drive), macOS asks once for Files-and-Folders access — click OK.

3. Connect ChatGPT: Settings → Plugins → turn on Developer mode (Security & login) → Create a custom plugin → paste the MCP Server URL `https://secondbrainbridge.vercel.app/mcp` → Authentication OAuth → sign in & Allow.

That's it. In a new chat: *"Search my notes for the Q3 planning doc"* or *"What did I decide about Project Atlas?"*

Your Mac must be awake with the agent running. npx second-brain-agent install makes it start automatically at login and restart if it ever crashes.

Managing the agent

npx second-brain-agent status      # is it paired & reachable?

npx second-brain-agent logs # recent activity npx second-brain-agent uninstall # stop auto-start

What ChatGPT can do

Tool	Action	Plan
`search_knowledge`	Search your vault by keyword; returns ranked passages	Free
`ask`	Ask a question and get an answer grounded in your own notes	Free
`get_note`	Read one full note by title or id	Free
`list_sources`	List the folders/sources in your vault	Free
`backlinks`	Show the notes that link to a note (the `[[wikilinks]]` graph)	Pro
`create_note`	Create a new Markdown note in your vault	Pro
`get_plan`	Show your current plan and an upgrade link	Free

Retrieval is v1 ranked keyword + title match, so answers stay grounded in the passages that actually appear in your notes. (Semantic/cloud ranking is a Pro/cloud enhancement.)

Plans

SecondBrainBridge is free to start. Upgrade to Pro when you want the full graph and write access.

	Free	Pro — $8/mo
Search, ask, and read your notes	✓	✓
List folders/sources	✓	✓
Searches per day	20 / day	Unlimited
Backlinks / `[[wikilinks]]` graph	—	✓
Create notes from chat	—	✓
Cloud aggregation across Macs	—	coming soon

Billing is handled by [Stripe](https://stripe.com). Upgrade at [secondbrainbridge.vercel.app/upgrade](https://secondbrainbridge.vercel.app/upgrade), and run get_plan in any chat to see your current plan plus an upgrade link. The relay enforces the Free daily cap and gates the Pro tools by your Stripe subscription (test mode for now).

Self-hosting

You can run your own relay so nothing depends on the hosted instance.

Prereqs: a Vercel account and a Supabase project (free tiers are fine).

Storage — in your Supabase project's SQL editor, run supabase/schema.sql. It creates a tiny Redis-shaped KV + queue surface (nb_* functions) with RLS on.
Deploy the server/ directory to Vercel.
Set env vars (see server/.env.example):

SUPABASE_URL, SUPABASE_SERVICE_ROLE_KEY — your project + service-role key
JWT_SECRET — openssl rand -hex 32
STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET — for the Pro tier (optional; Free-only if omitted)

Verify: curl https://YOUR-APP.vercel.app/api/health → redisConfigured, redisOk, jwtSecretSet all true.
Point the agent at it: npx second-brain-agent pair --server https://YOUR-APP.vercel.app.

How it works

Auth — OAuth 2.1 with PKCE and Dynamic Client Registration (RFC 7591). ChatGPT registers itself, the user signs in on the SecondBrainBridge consent page, and ChatGPT gets a scoped MCP access token. JWTs are HMAC-signed; three kinds (session, agent, mcp) with distinct privileges. Optional email verification via Resend (RESEND_API_KEY); off unless configured, and enforcement is opt-in (REQUIRE_EMAIL_VERIFICATION).
Relay — MCP tool call → job pushed to jobs: (TTL ≤ the caller's wait window, so an abandoned job can't run late) → the Mac agent (holding a hanging long-poll) is handed the job within ~200ms, executes it, pushes the result → the MCP handler returns it. The long-poll means jobs are delivered on arrival rather than on a fixed interval, so relay overhead is ~300ms instead of ~1s. The agent is considered "online" only while it's actively connected. The relay also enforces the Free daily search cap and unlocks the Pro tools based on the account's Stripe subscription.
Agent — a dependency-free Node CLI. It indexes the Markdown files in your vault folder and answers retrieval queries locally (ranked keyword + title match); create_note writes a new Markdown file into the vault. Reads and writes happen straight against the filesystem — the first touch of a protected folder triggers the one-time macOS Files-and-Folders prompt. A macOS LaunchAgent keeps it alive across logins and crashes.

Repository layout

server/    Vercel functions: OAuth + MCP endpoint + relay + Stripe billing   (deploy this)

agent/ second-brain-agent — the npm-published Mac CLI that indexes your vault (users npx this) kit/ Browser automations: register the dev-mode connector AND fill the OpenAI directory submission (see kit/README.md) supabase/ schema.sql for self-hosting the storage test/ end-to-end OAuth + MCP integration test

Development

# server

cd server && cp .env.example .env.local # fill in, then: vercel dev

end-to-end test against a live deployment (reads ../.env.local)

node test/e2e-oauth.mjs

agent unit tests

node --test agent/test-agent-unit.mjs

Security & privacy

Notes are read/written only on your Mac. The relay temporarily stores requested content in short-lived job/result queues — job payloads live in Redis-shaped storage with a short TTL and are deleted on delivery.
The agent token (and your vault path) is stored at ~/.secondbrainbridge-agent.json (mode 600); the vault path can also come from SECONDBRAIN_VAULT.
No secrets are committed; see .gitignore and the .env.example files.
The write tool (create_note) is marked destructive so ChatGPT asks before adding a note.

License

Production storage and owner verification

Relay 1.4 uses isolated service-role-only tables/functions on the configured shared Supabase project. Production refuses missing storage configuration, bounds RPC requests to ten seconds, and returns HTTP 503 when storage or signing configuration is unavailable. Apply the checked-in isolated-storage migration before deploying this version; it does not replace another bridge's account tables or functions.

node --env-file=.env.local test/live-storage.mjs verifies the actual persistent store, FIFO, expiry and counters using temporary integration keys. BRIDGE_SESSION_FILE=/private/owner-session.json BRIDGE_READ_TOOL=READ_TOOL node test/live-relay.mjs verifies the actual owner session, PKCE OAuth, hosted MCP and paired-Mac read; choose this bridge's inventory tool. No reviewer data counts as a live acceptance. Credentials and sessions belong outside Git.

Private vault index (source agent 1.1)

Requires Node 22.13+. Set the exact vault in the agent config, then run node agent/cli.mjs index-install. This builds a private SQLite snapshot under ~/Library/Application Support/SecondBrainBridge/ and incrementally checks changes every 15 minutes. It indexes Markdown/text files, excludes dot directories and symlinks, and reports the complete count without a silent 5,000-file cap. Search/list responses include the snapshot time and 15-minute freshness boundary. Fetch reads current file text; creating a note refuses overwrites and invalidates the snapshot. No embedding/model service is started.

node agent/cli.mjs index-status reports counts and freshness. node test/live-index.mjs checks actual ID coverage, private permissions, live text comparisons and read/search results. uninstall removes the refresh job while retaining the private index. No npm publication is claimed for this source upgrade.

Second Brain Bridge

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Docs, sheets & office worki

Common questions

Alternatives

Agent-Native Calendar

Excel MCP Server

MCP Server for Excel

README from the maker

🧠 SecondBrainBridge

For users — 3 steps

Managing the agent

What ChatGPT can do

Plans

Self-hosting

How it works

Repository layout

Development

end-to-end test against a live deployment (reads ../.env.local)

agent unit tests

Security & privacy

License

Production storage and owner verification

Private vault index (source agent 1.1)