Vault Bridge

Read-only access to a private Obsidian vault from ChatGPT.

Vault Bridge is a macOS application that copies a filtered snapshot of a vault to an isolated Docker project on your own Linux server. OpenAI Secure MCP Tunnel connects that private MCP server to ChatGPT without a public port or inbound access to the Mac.

Install with Codex · Releases · Architecture · Security

The current Apple Silicon preview is integrity-checked but not Developer ID signed or notarized. Do not bypass a macOS security warning for an untrusted download. The supported preview path is the Codex installation runbook.

What it does

• selects any local Obsidian vault;
• connects to an existing Linux server over SSH;
• installs an isolated, resource-bounded Docker Compose project;
• publishes complete vault snapshots on startup, every five minutes, after resume, or on demand;
• exposes only search and fetch to ChatGPT;
• shows connection state, synchronization state, and an aggregate activity log in one desktop application.
• provides one redacted doctor --json check for the vault, SSH/runtime, OpenAI tunnel, and last synchronization result.

The application does not write to the vault. It does not expose iCloud, a local filesystem, the Docker socket, a shell, or a public server port.

Install

For an agent-guided installation, open docs/install-with-codex.md, copy the prompt, and paste it into Codex. The runbook keeps account login, credentials, and the first SSH fingerprint approval with the owner.

Requirements:

• Apple Silicon Mac;
• Linux server reachable over SSH;
• Docker Engine with Docker Compose on the server;
• access to OpenAI Secure MCP Tunnels and the corresponding ChatGPT connection surface.

Release downloads include a DMG, ZIP, and SHA-256 manifest. Read the release notes before installing; preview binaries are not yet notarized.

Architecture

flowchart LR
    phone["Obsidian on phone"] <-->|"iCloud or Obsidian Sync"| vault["Vault on Mac"]
    vault -->|"local read-only scan"| app["Vault Bridge"]
    app -->|"SSH snapshot upload"| runtime["Docker project on your server"]
    runtime -->|"outbound HTTPS"| tunnel["OpenAI Secure MCP Tunnel"]
    tunnel <--> chat["ChatGPT"]

The vault on the Mac remains canonical. The server copy is replaceable and activates as one complete generation after validation. Phone-to-Mac freshness remains the responsibility of iCloud or Obsidian Sync.

ChatGPT tools

The MCP surface is deliberately small:

• search({ query }) returns bounded matches with opaque IDs;
• fetch({ id }) returns one document from the active snapshot.

There is no model-facing browse-all, write, delete, sync-control, raw-path, SQL, or shell tool. Vault content is treated as untrusted source data.

Secure MCP Tunnel supports private connections and developer-mode testing. It does not publish Vault Bridge to the public ChatGPT app catalog.

Security model

• Hidden directories, .obsidian, .git, node_modules, and symlinks are excluded by default.
• SSH host identity is approved once and pinned.
• The server process is non-root and resource-bounded, with no host ports, host mounts, privileged mode, or Docker socket.
• The OpenAI runtime key is accepted through the native UI or stdin and stored with macOS encrypted storage. It is not accepted in setup JSON or process arguments.
• Activity records counts, bytes, duration, trigger, generation, and a bounded component/error code when an operation fails. It does not record note contents, titles, queries, credentials, addresses, or local paths.
• The local journal retains at most 200 events. Container logs rotate at 8 MiB × 3 files, and temporary deployment secrets are removed after every setup attempt.
• The VPS administrator and Docker daemon can inspect the replica. Use a server you trust.

See the threat model and deployment contract. Report vulnerabilities through SECURITY.md, without vault evidence in a public issue.

Status

Surface	Current preview
macOS	Apple Silicon; not notarized
Vault data	Markdown, Canvas, and Bases text
MCP	Read-only search and fetch
Sync	Startup, five-minute schedule, resume, manual
Runtime	Docker Compose; Linux amd64 and arm64
Installation	Codex runbook or source build

The public roadmap is tracked in GitHub Issues.

Development

Requires Node.js 24+ and pnpm 10.

pnpm install --frozen-lockfile
pnpm check
pnpm dev

Use only synthetic fixtures during development. The repository is a TypeScript monorepo:

• apps/desktop — macOS application and deployment owner;
• apps/agent — vault scanner and snapshot publisher;
• apps/server — SQLite/FTS5 store and MCP server;
• deploy/secure-tunnel — isolated Docker Compose deployment;
• packages/* — shared contracts and libraries;
• apps/edge, deploy/runtime — advanced public HTTPS/OAuth mode.

See CONTRIBUTING.md. Licensed under Apache-2.0.