Write data by sending PUT, POST, PATCH, or DELETE requests. The request body is JSON.
Set (PUT)
Replace the data at a path completely. Any existing data at that path is overwritten.
curl -X PUT \
'https://chess-app.larkdb.net/my-game/players/alice.json?auth=YOUR_TOKEN' \
-d '{"name": "Alice", "score": 250, "online": true}'
{
"name": "Alice",
"score": 250,
"online": true
}
PUT to a path that doesn’t exist creates it. PUT to a path that does exist replaces it entirely — missing fields are deleted, not preserved.
Push (POST)
Add a new child with an auto-generated key. This is the REST equivalent of push() in the SDKs.
curl -X POST \
'https://chess-app.larkdb.net/my-game/messages.json?auth=YOUR_TOKEN' \
-d '{"text": "Hello!", "sender": "alice", "timestamp": {".sv": "timestamp"}}'
{
"name": "-Kabc123def"
}
name field contains the generated key. Push IDs are chronologically sortable — later posts sort after earlier ones.
Use POST for append-only data like chat messages, event logs, or queue items where each entry needs a unique key.
Update (PATCH)
Merge data into an existing path. Only the specified keys are modified — everything else is preserved.
curl -X PATCH \
'https://chess-app.larkdb.net/my-game/players/alice.json?auth=YOUR_TOKEN' \
-d '{"score": 300, "lastSeen": {".sv": "timestamp"}}'
score and lastSeen without touching name or online.
Multi-path updates
Update multiple locations atomically by using paths as keys in your PATCH body at a higher level:
curl -X PATCH \
'https://chess-app.larkdb.net/my-game/.json?auth=YOUR_TOKEN' \
-d '{
"players/alice/score": 300,
"players/bob/score": 275,
"leaderboard/first": "alice",
"leaderboard/second": "bob"
}'
Remove (DELETE)
Delete data at a path.
curl -X DELETE \
'https://chess-app.larkdb.net/my-game/players/alice.json?auth=YOUR_TOKEN'
null on success. Deleting a non-existent path succeeds silently.
Server values
Use {".sv": "timestamp"} to write the server’s current timestamp:
curl -X PUT \
'https://chess-app.larkdb.net/my-game/players/alice/lastSeen.json?auth=YOUR_TOKEN' \
-d '{".sv": "timestamp"}'
{".sv": "timestamp"} with the actual Unix timestamp in milliseconds.
Silent writes
If you don’t need the response body (saving bandwidth), add print=silent:
curl -X PUT \
'https://chess-app.larkdb.net/my-game/players/alice/score.json?auth=YOUR_TOKEN&print=silent' \
-d '500'
204 No Content instead of echoing the written data.
Error responses
When a write fails, you get an error object:
{
"error": "permission_denied",
"message": "You do not have permission to write to this path"
}
| Status code | Meaning |
|---|
200 | Write succeeded |
204 | Write succeeded (with print=silent) |
400 | Invalid JSON or bad request |
403 | Security rules denied the write |
401 | Authentication required |
