Firebase Database REST API

access_token

Supported by all request types. Authenticates this request to allow access to data protected by Firebase Realtime Database Security Rules. See the REST authentication documentation for details.

curl 'https://[PROJECT_ID].firebaseio/users/jack/name.json?access_token=CREDENTIAL'

shallow

This is an advanced feature, designed to help you work with large datasets without needing to download everything. Set this to true to limit the depth of the data returned at a location. If the data at the location is a JSON primitive (string, number or boolean), its value will simply be returned. If the data snapshot at the location is a JSON object, the values for each key will be truncated to true.

Arguments	REST Methods	Description
shallow	GET	Limit the depth of the response.

curl 'https://[PROJECT_ID].firebaseio/.json?shallow=true'

Note that shallow cannot be mixed with any other query parameters.

print

Formats the data returned in the response from the server.

Arguments	REST Methods	Description
pretty	GET, PUT, POST, PATCH, DELETE	View the data in a human-readable format.
silent	GET, PUT, POST, PATCH	Used to suppress the output from the server when writing data. The resulting response will be empty and indicated by a 204 No Content HTTP status code.

curl 'https://[PROJECT_ID].firebaseio.com/users/jack/name.json?print=pretty'

curl -X PUT -d '{ "first": "Jack", "last": "Sparrow" }' \
  'https://[PROJECT_ID].firebaseio.com/users/jack/name.json?print=silent'

callback

Supported by GET only. To make REST calls from a web browser across domains, you can use JSONP to wrap the response in a JavaScript callback function. Add callback= to have the REST API wrap the returned data in the callback function you specify.

<script>
  function gotData(data) {
    console.log(data);
  }
</script>
<script src="https://[PROJECT_ID].firebaseio.com/.json?callback=gotData"></script>

format

If set to export, the server will encode priorities in the response.

Arguments	REST Methods	Description
export	GET	Include priority information in the response.

curl 'https://[PROJECT_ID].firebaseio.com/.json?format=export'

download

Supported by GET only. If you would like to trigger a file download of your data from a web browser, add download=. This causes the REST service to add the appropriate headers so that browsers know to save the data to a file.

curl 'https://[PROJECT_ID].firebaseio/.json?download=myfilename.txt'

timeout

Use this to limit how long the read takes on the server side. If a read request doesn't finish within the allotted time, it terminates with an HTTP 400 error. This is particularly useful when you expect a small data transfer and don't want to wait too long to fetch a potentially huge subtree. Actual read time might vary based on data size and caching.

Specify timeouts using the following format: 3ms, 3s, or 3min, with a number and a unit. If not specified, the maximum timeout of 15min will be applied. If the timeout is not positive, or exceeds the maximum, the request will be rejected with an HTTP 400 error.

writeSizeLimit

To limit the size of a write, you can specify the writeSizeLimit query parameter as tiny (target=1s), small (target=10s), medium (target=30s), large (target=60s). Realtime Database estimates the size of each write request and aborts requests that will take longer than the target time.

If you specify unlimited, exceptionally large writes (with up to 256MB payload) are allowed, potentially blocking subsequent requests while the database processes the current operation. Writes cannot be canceled once they reach the server.

curl -X DELETE 'https://docs-examples.firebaseio.com/rest/delete-data.json?writeSizeLimit=medium'

You will see the following error message if the write is too big:

Error: WRITE_TOO_BIG: Data to write exceeds the maximum size that can be modified with a single request.

Additionally, you can set the defaultWriteSizeLimit for the whole database instance using the Firebase CLI. This limit applies to all requests, including those from SDKs. New databases are created with defaultWriteSizeLimitset to large. You can't set defaultWriteSizeLimit to tiny using the Firebase CLI.

firebase database:settings:set defaultWriteSizeLimit large

orderBy

See the section in the guide on ordered data for more information.

limitToFirst, limitToLast, startAt, endAt, equalTo

See the section in the guide on filtering data for more information.

event: event name
data: JSON encoded data payload

put

The JSON-encoded data is an object with two keys: path and data. The path key points to a location relative to the request URL. The client should replace all of the data at that location in its cache with data.

patch

The JSON-encoded data is an object with two keys: path and data. The path key points to a location relative to the request URL. For each key in data, the client should replace the corresponding key in its cache with the data for that key in the message.

keep-alive

The data for this event is null. No action is required.

cancel

Some unexpected errors can send a `cancel` event and terminate the connection. The cause is described in the data provided for this event. Some potential causes are as follows: 1. The Firebase Realtime Database Security Rules no longer allow a read at the requested location. The `data` description for this cause is "Permission denied." 2. A write triggered an event streamer that sent a large JSON tree that exceeds our limit, 512MB. The `data` for this cause is "The specified payload is too large, please request a location with less data."

auth_revoked

The data for this event is a string indicating that a the credential has expired. This event is sent when the supplied auth parameter is no longer valid.

// Set your entire cache to {"a": 1, "b": 2}
event: put
data: {"path": "/", "data": {"a": 1, "b": 2}}

// Put the new data in your cache under the key 'c', so that the complete cache now looks like:
// {"a": 1, "b": 2, "c": {"foo": true, "bar": false}}
event: put
data: {"path": "/c", "data": {"foo": true, "bar": false}}

// For each key in the data, update (or add) the corresponding key in your cache at path /c,
// for a final cache of: {"a": 1, "b": 2, "c": {"foo": 3, "bar": false, "baz": 4}}
event: patch
data: {"path": "/c", "data": {"foo": 3, "baz": 4}}