If you’re reading this, someone sent you a link because they want to set up a shared folder with you. This takes about 5 minutes.

Quick Start (Claude Code)

If you use Claude Code, paste this into your terminal:

Can you help me set up a shared Syncthing folder? Here's the guide: https://hedwards.dev/shared-knowledge-sync/

Claude will walk you through it. Skip to What You’re Setting Up if you want context first.

Quick Start (Manual)

  1. Install Syncthing (if you haven’t already)

    • macOS: brew install syncthing && brew services start syncthing
    • Linux: sudo apt install syncthing && systemctl --user enable --now syncthing
    • Windows: winget install Syncthing.Syncthing

  2. Open the web UI at http://localhost:8384

  3. Create a folder in your Obsidian vault called Shared - [Friend's Name]/

  4. Get your Device ID: Actions → Show ID. Send it to your friend.

  5. Add your friend’s device: Add Remote Device → paste their ID → Save

  6. Add the shared folder: Add Folder → set Folder ID to something you both agree on (e.g., shared-harrison-alice) → select the folder you created → Sharing tab → check your friend’s device → Save

Your friend does the same on their end. Once both sides are configured, sync starts automatically.

What You’re Setting Up

Syncthing keeps folders in sync between computers - like Dropbox, but peer-to-peer with no cloud server in the middle. Free, open source, runs locally.

When you save a file, it appears on your friend’s computer within seconds (as long as you’re both online). If one of you is offline, changes queue up and sync when you reconnect.

What goes in the shared folder:

  • Prompts that worked well
  • CLAUDE.md snippets worth reusing
  • Workflow discoveries
  • Async questions for each other

What stays out:

  • Anything you wouldn’t share with this person
  • Personal vault content (the rest of your vault isn’t affected)

Syncing an Entire Vault

The guide above covers a shared subfolder inside your vault - good for swapping prompts and tips while keeping your vaults separate. But if you want to work from the same vault (e.g., a family or team knowledge base), Syncthing handles that too.

Setup is the same - just point Syncthing at the vault root instead of a subfolder. The one difference is you’ll want a .stignore file in the vault root to avoid stepping on each other’s Obsidian settings:

// .stignore - place in the vault root
// Each person's Obsidian config stays independent

.obsidian/workspace.json
.obsidian/workspace-mobile.json
.trash/

workspace.json tracks which panes/files are open - without ignoring it, opening a note on one machine rearranges the other person’s layout. .trash/ is Obsidian’s soft-delete folder; syncing it causes deleted files to reappear.

If you also want independent plugin configs, hotkeys, or themes, add:

.obsidian/plugins/
.obsidian/hotkeys.json
.obsidian/appearance.json

Otherwise leave those out and you’ll share a consistent setup - useful when one person is managing the vault config for both.

Conflicts are more likely with a shared vault than a shared subfolder, since you might both edit the same note. See Conflicts below - Syncthing creates .sync-conflict files rather than overwriting, so nothing is lost.

For Claude Code

This section helps Claude Code guide you through setup. You can skip it.

Installation Commands

macOS (Homebrew - recommended):

brew install syncthing
brew services start syncthing

macOS (standalone): Download from syncthing.net/downloads, move to Applications, open. Grant folder access when prompted. If macOS blocks it: System Settings → Privacy & Security → Open Anyway.

Linux (apt-based):

sudo apt install syncthing
systemctl --user enable syncthing
systemctl --user start syncthing

Windows:

winget install Syncthing.Syncthing

After installation, the web UI is at http://localhost:8384

Verifying Installation

Check if Syncthing is running:

# Linux
systemctl --user status syncthing

# macOS (Homebrew)
brew services list | grep syncthing

# Any platform - if this returns JSON, it's running
curl -s http://localhost:8384/rest/system/status | head -c 100

Getting the Device ID

In the web UI: Actions (top right) → Show ID

Or via CLI/API:

# Subcommand (simplest, no running instance needed)
syncthing device-id

# Or via REST API (requires running instance)
curl -s http://localhost:8384/rest/system/status | jq -r '.myID'

The Device ID is a long string like XXXXXXX-XXXXXXX-XXXXXXX-XXXXXXX-XXXXXXX-XXXXXXX-XXXXXXX-XXXXXXX. This is what you exchange with your friend.

Folder Setup

Folder ID: Both computers must use the same Folder ID. The folder name and path can differ - only the ID matters. Agree on an ID with your friend before starting (e.g., shared-harrison-alice).

Folder location: Inside the Obsidian vault, e.g.:

  • ~/Notes/Shared - Harrison/
  • /mnt/nas/Files/05 Resources/Shared - Alice/

The exact path depends on where the user’s vault lives.

Adding a Remote Device

  1. Get your friend’s Device ID (they send it via chat/email)
  2. In Syncthing web UI: Add Remote Device
  3. Paste the Device ID
  4. Give it a name (e.g., your friend’s name)
  5. Save
  6. Your friend must also add your device on their end

Adding the Shared Folder

  1. In Syncthing web UI: Add Folder
  2. Folder ID: The agreed-upon ID (e.g., shared-harrison-alice)
  3. Folder Path: Browse to or enter the path to the folder you created
  4. Sharing tab: Check the box next to your friend’s device
  5. Save

If your friend already set up the folder on their end, Syncthing may prompt you to accept a shared folder instead - that’s fine, just confirm and set the local path.

Folder Structure Suggestions

Shared - [Friend's Name]/
├── Prompts/
│   └── [dated or descriptive names].md
├── Discoveries/
│   └── 2026-01-23 - Thing I found.md
├── CLAUDE.md Snippets/
│   └── [reusable context sections].md
└── Questions.md   # async back-and-forth

Conventions that help:

  • Prefix files with your initials if you’re both adding to the same subfolder
  • Date discoveries so the timeline is scannable
  • When adding a prompt, include context: what it’s for, when it works, caveats

Edge Cases

Conflicts

If you both edit the same file at the same time, Syncthing creates a .sync-conflict file rather than overwriting. This is rare - you’re typically adding new files, not editing the same one simultaneously.

If it happens often, switch to append-only: each person has their own files, you read each other’s rather than co-editing.

Git Integration

If you version your vault with git, add the shared folder to .gitignore:

Shared - */

This keeps your git history clean - Syncthing handles the shared folder, git handles everything else. Without this, your commits include changes your friend made (delivered via Syncthing), which confuses attribution and bloats both repos.

If you want version history for shared content, initialise a separate git repo inside the shared folder:

cd "Shared - Friend/"
git init
git add -A
git commit -m "Initial shared knowledge base"

Privacy

Everything in the shared folder is visible to your friend. Use Syncthing’s .stignore file if you need to exclude specific files from sync.

Offline Behaviour

Both computers need to be online simultaneously for sync to happen. If your friend’s laptop is off, changes queue up and sync when they reconnect. No data is lost - just delayed.