# License

> Collaboration SDK uses the License to decide collaborative editing connections, authorized domains, collaboration nodes and document types.

- Human documentation: [https://docs.univer.ai/server/collaboration/license](https://docs.univer.ai/server/collaboration/license)

- Agent Markdown: [https://docs.univer.ai/server/collaboration/license.md](https://docs.univer.ai/server/collaboration/license.md)

- Requested language: `en-US`

- Content language: `en-US`

- Documentation version: `1.4.0`

- Source: [collaboration/license.mdx](https://github.com/dream-num/documentation/blob/dev/content/server/collaboration/license.mdx)

---

`UniverCollabService` loads the License at construction, and Endpoints and Worktrees share it. See [License](https://docs.univer.ai/server/license.md#collaboration-sdk) for configuration; without a License it runs on the free tier. A License that fails verification makes the constructor throw a `CollabError` (`LICENSE_INVALID` or `LICENSE_POLICY_INVALID`), so the service stops at startup.

## What the License decides

| Item                             | Checked at                                         | Beyond the limit                                       |
| -------------------------------- | -------------------------------------------------- | ------------------------------------------------------ |
| Collaborative editing connections | Endpoint, when receiving submissions              | Edits from new connections stay in the browser and retry |
| Authorized domains               | Endpoint, when connecting and receiving submissions | The browser's collaboration session goes offline      |
| Collaboration nodes              | Endpoint                                           | Nodes beyond the limit go offline after a grace period |
| Document types                   | Service, when creating Units and submitting edits  | Creation and submissions are rejected; existing documents stay viewable |

### Collaborative editing connections

The allowance counts connections that are editing: a collaboration connection takes a slot on its first successful submission and releases it when the connection closes or 120 seconds after its last successful submission. Connections that open a document to view it can join at any time. Edits inside a Worktree share the same pool as the trunk.

When every slot is in use, edits from a new connection stay in the browser and Web SDK resends them with backoff until a slot frees up; connections that already hold a slot keep editing. `CollaborationChangesetResend` in the browser reports these resends with `reason: 'license_editing_connections_exceeded'`.

### Authorized domains

When Web SDK opens a collaboration connection or submits edits, the Endpoint checks the page's domain against the License's authorized domains. A domain outside them receives `403`; the browser's collaboration session goes offline and shows the reason, and tries again when the user reconnects or opens another document.

### Collaboration nodes

**Single-node License** (including the free tier): runs one collaboration node. Passing `pubSub` to the Endpoint makes the constructor throw `LICENSE_POLICY_INVALID`.

**Multi-node License**: sets a node limit. When more nodes run than the limit, the newest ones enter a grace period with escalating warnings and then go offline: new connections receive `503` and existing connections close. Nodes within the limit keep serving. If the count drops back within the limit during the grace period, the extra nodes return to normal; a node that has gone offline is counted again as a new node after its process restarts. See [Deployment](https://docs.univer.ai/server/deployment.md#multiple-collaboration-nodes) for multi-node setups.

### Document types

The License lists the document types available for collaboration. Creating a Unit of another type throws `LICENSE_UNIT_TYPE_REJECTED`, and submitted edits are rejected, with `CollaborationConflict` in the browser reporting `reason` `license_unit_type_rejected`; existing documents stay viewable.

## Observe the state

```ts
// Service
collabService.license.status // License status: 'not_configured' | 'expired' | 'valid'
collabService.license.editingConnectionsLimit // editing connection limit: number | null; null means unlimited
collabService.license.nodesLimit // node limit: number | null; null means unlimited
collabService.license.domains // authorized domains: string[]
collabService.license.expiresAt // expiry time: ISO string | null; null when not configured
collabService.license.update({ license, licenseKey }) // replace the License; throws and keeps the current one if verification fails

// Endpoint
endpoint.license.editingConnections.limit // slot limit: number | null; null means unlimited
endpoint.license.editingConnections.used // slots in use: number | null; null when limit is unlimited
endpoint.license.editingConnections.remaining // slots left: number | null; null means unlimited
endpoint.license.editingConnections.has(memberID) // whether this member holds a slot: boolean; false when limit is unlimited
endpoint.license.nodes.limit // node limit: number | null; null means unlimited
endpoint.license.nodes.status // this node's status: 'normal' | 'exceeded' | 'exceeded-warning' | 'exceeded-offlineSoon' | 'exceeded-offline'

// Events
endpoint.license.on('editingConnectionsChanged', ({ change, memberIDs, used, limit }) => {}) // slots were taken or given back: change is 'acquired' | 'released', used is the value after the change; not fired when limit is unlimited
endpoint.license.on('editingConnectionsExceeded', ({ memberID, userID, unitID, used, limit }) => {}) // slots are full and a new connection's submission was held back
endpoint.license.on('nodesStatusChanged', ({ status, previousStatus, limit, reason }) => {}) // this node's status changed; reason is set only when it goes offline
```

`nodesStatusChanged` fires once each time this node's status changes. When `status` is `exceeded-offline`, the node has stopped accepting connections; take it out of the load balancer or raise an alert.