---
title: Pair and Connect Libraries
description: Establish device trust and attach remote library state
sidebarTitle: Library Sync Setup
---

Pair devices first, then choose which library relationship to establish. Pairing
creates device trust. Library setup creates scoped shared state.

## 1. Check networking

Run on both devices:

~~~bash
sd-cli network status
~~~

Each daemon should report a node ID and active networking.

## 2. Pair the devices

On the device that will show the code:

~~~bash
sd-cli network pair generate
~~~

On the joining device:

~~~bash
sd-cli network pair join "<PAIRING_CODE>"
~~~

The joiner prints "Paired with <name>" and both daemons record trust; there is
no confirmation prompt. The code expires after five minutes.

If the two devices are not on one local network, take the initiator's node ID
from `sd-cli --format json network pair generate` (field `node_id`) and pass it
to the joiner:

~~~bash
sd-cli network pair join "<PAIRING_CODE>" --node-id <NODE_ID>
~~~

Check the result on either side:

~~~bash
sd-cli network devices
sd-cli network status
~~~

Pairing only records network trust. `sd-cli devices list` reads the current
library's device table and does not show the new peer yet.

## 3. Inspect libraries

List local libraries:

~~~bash
sd-cli library list
~~~

Discover libraries exposed by the paired device:

~~~bash
sd-cli library sync-setup discover <REMOTE_DEVICE_ID>
~~~

Discovery follows the remote device's current grants. An undisclosed library is
not evidence that it does not exist.

## 4. Join the remote library

On the device that should become a member, join the library the other device
already holds:

~~~bash
sd-cli library sync-setup setup \
  --local-library <ANY_LOCAL_LIBRARY_ID> \
  --remote-device <REMOTE_DEVICE_ID> \
  --remote-library <REMOTE_LIBRARY_ID> \
  --action join-remote \
  --name "<LIBRARY_NAME>"
~~~

`--local-library` names any library already open on this device; the command
needs one to address the daemon and does not change it. The join:

1. creates a new local library with the remote library's UUID (the folder name
   is de-duplicated, for example `My Library 1.sdlibrary`);
2. registers this device in the remote device's copy of the library and
   receives the remote device's record in return, so both device tables are
   complete when the command returns;
3. marks the new library as waiting for its first backfill, so sync pulls the
   existing member's state into it. The existing member keeps its data and
   never adopts the empty joiner's snapshot.

The other direction, `--action share-local`, runs on the device that holds the
library and creates the copy on the peer. `--interactive` walks through the same
choices.

Then select the joined library on this device:

~~~bash
sd-cli library switch --library-id <REMOTE_LIBRARY_ID>
~~~

Use stable library and device UUIDs. Do not parse display names as identity.

## 5. Confirm state

~~~bash
sd-cli devices list
sd-cli library info
sd-cli network devices --connected
sd-cli sources list
sd-cli job list
~~~

`devices list` on both devices now shows both members. `library info` reports
fleet totals: file, content, source, and capacity figures are the sum of every
library member's own numbers, and the device count is the number of members.
A joined device that has registered no sources of its own therefore reports the
same totals as the device that holds the data.

Library sync can complete before every remote source is online. Source
availability and source-generation replication have their own state; a peer's
source replicas start arriving when the devices connect, independent of the
join.

## What setup does not do

Connecting libraries does not:

- copy every source generation into the library database;
- download all file bytes;
- expose ungranted local paths;
- turn a remote browse into a backup;
- make two devices share unrestricted mutation rights.

Remote source serving, source-store subscription, caching, and file sync are
separate choices.

## Troubleshooting

### The peer is not discovered

Use the QR payload or node ID for internet pairing. Check that both daemons have
networking enabled and that the code has not expired.

### Pairing works but discovery returns no libraries

Review the remote device's library grant. Pairing proves identity but does not
grant every library.

### `devices list` shows one device after pairing

Pairing does not add the peer to a library. Run the join in step 4; the peer
appears in `devices list` on both sides when it returns.

### Metadata appears but files do not open

The source store may be cached while its origin is offline, or the grant may
allow metadata but not bytes. Inspect source availability and subtree scope.

### A job remains after reconnect

Query the job on the device executing it. Durable jobs remain owned by that
daemon and can outlive the client connection.

See [Device Pairing](/core/pairing), [Library Sync](/core/library-sync), and
[File Sync](/core/file-sync).