Locked

Overview

423 Locked means the resource being accessed is locked (a WebDAV lock), so the request cannot proceed. WebDAV provides an explicit LOCK mechanism so collaborators do not overwrite each other's edits to the same file.

When one user has locked a file and another tries to write to it (PUT/DELETE/MOVE) without a valid lock token, the server returns 423. It mainly appears in document-collaboration setups (Microsoft Office, Nextcloud, ownCloud).

When it happens

• Trying to modify, delete, or move a WebDAV file locked by another user
• Attempting to write to a locked resource without a valid lock token
• A collaborative editing tool holds the file locked while it is being edited

Request / Response example

PUT /docs/report.docx HTTP/1.1
Host: dav.example.com
Content-Type: application/octet-stream

<file body>

HTTP/1.1 423 Locked
Content-Type: application/xml

<?xml version="1.0"?>
<D:error xmlns:D="DAV:"><D:lock-token-submitted/></D:error>

In code

app.put('/docs/:name', (req, res) => {
  const lock = locks.get(req.params.name);
  if (lock && lock.token !== req.headers['if']) {
    return res.status(423).type('xml')
      .send('<D:error xmlns:D="DAV:"><D:lock-token-submitted/></D:error>');
  }
  // write the file...
});

# Supply the lock token in the If header to edit a locked WebDAV resource
curl -X PUT https://dav.example.com/docs/report.docx \
  -H 'If: (<urn:uuid:lock-token-here>)' \
  --data-binary @report.docx

Notes

• 423 is a WebDAV extension code rarely seen in ordinary web APIs, where resource-state conflicts are usually expressed as 409 Conflict.
• The related 424 Failed Dependency is used when a separate action that depended on the locked resource also fails.

Related status codes

Related headers

Specification