JavaScript driver for Fauna v4 (deprecated)
[!WARNING]
Fauna is decommissioning FQL v4 on June 30, 2025.
This driver is not compatible with FQL v10, the latest version. Fauna accounts
created after August 21, 2024 must use FQL v10. Ensure you migrate existing
projects to the official v10 driver by the v4 EOL date:
https://github.com/fauna/fauna-js.
For more information, see the v4 end of life (EOL)
announcement and
related FAQ.
The official JavaScript driver for Fauna v4.
View reference JSDocs here.
See the FaunaDB Documentation and
Tutorials for
guides and a complete database API
reference.
Supported Runtimes
This Driver supports and is tested on:
Using the Client
Installation
Node.js
npm install --save faunadb
or
yarn add faunadb
Browsers
Via CDN:
<script src="//cdn.jsdelivr.net/npm/faunadb@latest/dist/faunadb.js"></script>
The minified version of the driver can also be used via CDN:
<script src="//cdn.jsdelivr.net/npm/faunadb@latest/dist/faunadb-min.js"></script>
Use
The tutorials in
the FaunaDB documentation contain other driver-specific examples.
Connecting from the browser
To get up and running quickly, below is a full example for connecting from the browser. Replace <your_key_here> with a database secret. You can get that by visiting your FaunaDB Dashboard, creating a new database, clicking on "Security" in the sidebar on the left, and then clicking "New Key". To learn more about keys, see FaunaDB Key System.
<html>
<head>
</head>
<body>
<h1>Test</h1>
</body>
<script src="https://cdn.jsdelivr.net/npm/faunadb@latest/dist/faunadb.js"></script>
<script type="text/javascript">
var faunadb = window.faunadb
var q = faunadb.query
var client = new faunadb.Client({
secret: 'your_key_here',
domain: 'db.fauna.com',
scheme: 'https',
})
client.query(
q.ToDate('2018-06-06')
)
.then(function (res) { console.log('Result:', res) })
.catch(function (err) { console.log('Error:', err) })
</script>
</html>
Requiring the Driver
var faunadb = require('faunadb'),
q = faunadb.query
This is the recommended require stanza. The faunadb.query
module contains all
of the functions to create FaunaDB Query expressions.
Instantiating a Client and Issuing Queries
var client = new faunadb.Client({ secret: 'YOUR_FAUNADB_SECRET' })
Once the client has been instantiated, it can be used to issue queries. For
example, to create an document in an existing collection named test
with the data:
{ testField: 'testValue' }
:
var createP = client.query(
q.Create(q.Collection('test'), { data: { testField: 'testValue' } })
)
All methods on faunadb.Client
return ES6 Promises.
So, if we wanted to handle the Promise to access the Ref
of the newly created
document:
createP.then(function(response) {
console.log(response.ref)
})
response
is a JSON object containing the FaunaDB response. See the JSDocs for
faunadb.Client
.
The metrics
option is used during instantiation to create a client that also
returns usage information about the queries issued to FaunaDB.
let client = new faunadb.Client({
secret: 'YOUR_FAUNADB_SECRET',
metrics: true
})
Querying and Returning the metrics of your queries
The response
object is shaped differently for clients when calling queryWithMetrics
;
it includes the value of the response along with a metrics field giving data on ops,
time, and transaction retires consumed by your query:
{
value: { ... },
metrics: {
x-compute-ops: XX,
x-byte-read-ops: XX,
x-byte-write-ops: XX,
x-query-time: XX,
x-txn-retries: XX
}
}
Metrics returned in the response will be of number
data type.
This driver contains helpers to provide a simpler API for consuming paged
responses from FaunaDB. See the Paginate function
reference
for a description of paged responses.
Using the helper to page over sets lets the driver handle cursoring and
pagination state. For example, client.paginate
:
var helper = client.paginate(q.Match(q.Index('test_index'), 'example-term'))
The return value, helper
, is an instance of PageHelper
. The each
method will execute a
callback function on each consumed page.
helper.each(function(page) {
console.log(page)
})
Note that each
returns a Promise<void>
that is fulfilled on the completion
of pagination.
The pagination can be transformed server-side via the FaunaDB query language
via the map
and filter
functions.
For example, to retrieve the matched documents:
helper
.map(function(ref) {
return q.Get(ref)
})
.each(function(page) {
console.log(page)
})
See the JSDocs for
more information on the pagination helper.
Timeouts
The client can be configured to handle timeouts in two different ways:
- Add a
timeout
field to the options
block when instantiating the client - By setting a
queryTimeout
on the client (or passing the value to the client's .query()
method directly)
The first option (i.e. timeout
) represents a HTTP timeout on the client side. Defined in seconds, the client will wait the specified period before timing out if it has yet to receive a response.
const client = new faunadb.Client({
secret: 'YOUR_FAUNADB_SECRET',
timeout: 100,
})
On the other hand, using the client's queryTimeout
dictates how long FaunaDB will process the request on the server before timing out if it hasn't finished running the operation. This can be done in two different ways:
const client = new faunadb.Client({
queryTimeout: 2000,
secret: 'YOUR_FAUNADB_SECRET',
})
var data = client.query(q.Paginate(q.Collections()), {
queryTimeout: 100,
})
Note: When passing a queryTimeout
value to client.query()
as part of the options
object, it will take precendence over any value set on the client when instantiating it.
Per-query options
Some options can be provided on a per-query basis:
secret
var createP = client.query(
q.Create(q.Collection('test'), { data: { testField: 'testValue' } }),
{ secret: 'YOUR_FAUNADB_SECRET' }
)
var helper = client.paginate(
q.Match(q.Index('test_index'), 'example-term'),
null,
{
secret: 'YOUR_FAUNADB_SECRET',
}
)
queryTimeout
var data = client.query(q.Paginate(q.Collections()), {
queryTimeout: 100,
})
traceparent
A W3C-compliant identifier for enabling distributed tracing across different
vendors. If not provided, one is automatically generated server-side and attached to the query. Customer's should
inspect the returned traceresponse to determine if a new traceparent has been created, and use that instead. See
Trace Context spec for more details.
var data = client.query(q.Paginate(q.Collections()), {
traceparent: "00-c91308c112be8448dd34dc6191567fa0-b7ad6b7169203331-01",
})
tags
Allows for associating user-provided tags with a query.
var data = client.query(q.Paginate(q.Collections()), {
tags: { key1: "value1", key2: "value2" },
})
Both tags and their associated values, must be strings. The only allowable characters are alphanumeric values as well
as an underscope (_). Max length for keys is 40 characters. Max length for values is 60 characters.
Custom Fetch
To use a custom fetch()
you just have to specify it in the configuration and make it compatible with the standard Web API Specification of the Fetch API.
const customFetch = require('./customFetch')
const client = new faunadb.Client({
secret: 'YOUR_FAUNADB_SECRET',
fetch: customFetch,
})
HTTP/2 Session Idle Time (Node.js only)
When running on the Node.js platform, the Fauna client uses HTTP/2 multiplexing
to reuse the same session for many simultaneous requests. After all open requests
have been resolved, the client will keep the session open for a period of time
(500ms by default) to be reused for any new requests.
The http2SessionIdleTime
parameter may be used to control how long the HTTP/2
session remains open while the query connection is idle. To save on the overhead of
closing and re-opening the session, set http2SessionIdleTime
to a longer time.
The default value is 500ms and the maximum value is 5000ms.
Note that http2SessionIdleTime
has no effect on a stream connection: a stream
is a long-lived connection that is intended to be held open indefinitely.
While an HTTP/2 session is alive, the client holds the Node.js event loop
open; this prevents the process from terminating. Call Client#close
to manually
close the session and allow the process to terminate. This is particularly
important if http2SessionIdleTime
is long:
const { Client, query: Q } = require('faunadb')
async function main() {
const client = new Client({
secret: 'YOUR_FAUNADB_SECRET',
http2SessionIdleTime: 1000,
})
const output = await client.query(Q.Add(1, 1))
console.log(output)
client.close()
}
main().catch(console.error)
Known issues
Using with Cloudflare Workers
Cloudflare Workers have neither XMLHttpRequest nor fetch in the global scope.
Therefore, the cross-fetch
package is unable to inject its own fetch()
function, and throws an error.
The fetch()
function is injected via a closure, so the workaround would be to pass
the fetch objects when initiating the FaunaDB client config. Cloudflare Workers also
doesn't support the use of an AbortController, which terminates requests as well as streams.
Here is a workaround:
const c = new faunadb.Client({
secret: 'your secret',
fetch: (url, params) => {
const signal = params.signal
delete params.signal
const abortPromise = new Promise(resolve => {
if (signal) {
signal.onabort = resolve
}
})
return Promise.race([abortPromise, fetch(url, params)])
},
})
Client Development
Run yarn
to install dependencies.
Code
This project includes no polyfills. Support for Internet Explorer 11 requires
a Promise
polyfill.
Testing
The driver tests need to connect to a FaunaDB so we recommend you setup one locally. The fast way is running a docker image like docker run --rm --name faunadb -p 8443:8443 fauna/faunadb
.
After have the faunadb working on local you have to setup a set of env variables before run the tests. You can set them manually or use a .env
file for this.
FAUNA_DOMAIN=localhost
FAUNA_SCHEME=http
FAUNA_PORT=8443
FAUNA_ROOT_KEY=secret
AUTH_0_URI=https://{TENANT}.auth0.com/
AUTH_0_TOKEN=auth0 token
Guide for Auth0
yarn test
: This will run tests against the current version of Node.js.
nvm is useful for managing multiple
versions of Node.js for testing.
Each test run will create a new database, and will attempt to clean it up when
done. If the tests are cancelled, the test database will not get cleaned up.
Therefore it is recommended to use a FaunaDB key scoped to an empty parent
database created for this purpose, rather than your account's root key. This
will make cleanup of test databases as easy as removing the parent database.
See the FaunaDB Multi-tenancy
Tutorial
for more information about nested databases.
Alternatively, tests can be run via a Docker container with
FAUNA_ROOT_KEY="your-cloud-secret" make docker-test
(an alternate
Alpine-based NodeJS image can be provided via RUNTIME_IMAGE
).
Documentation
yarn doc
will generate JSDoc documentation for the project.
Previewing upcoming functionality
If you want to preview unreleased features in your project, you can do so by installing this driver using one of the following methods.
1. Using a git URL
Normally, you would install the latest release of this package using npm install --save faunadb
or yarn add faunadb
. To access our latest features, you will need to define this dependency by using a git URL.
-
Open your package.json
file
-
If you have already installed this driver, you should see the following in your list of dependencies. If not, add it.
"faunadb": "^2.14.1"
- Instead of using a version from the npm registry, we'll want to point our
package.json
to the main
branch of our GitHub repo. To do that, change the ^2.4.1
to fauna/faunadb-js#main
.
"faunadb": "fauna/faunadb-js#main"
- Update your
node_modules
by running npm install
or yarn
2. Using npm pack
- Clone this repo to your local system
git clone https://github.com/fauna/faunadb-js.git
- Navigate to the cloned repo and open the
package.json
cd faunadb-js
code package.json
-
Change the version
to be semantic. For example, 3.0.0-beta
.
-
Run npm pack
. This creates a tarball at the root of your project directory which represents the image sent to the NPM registry when publishing.
-
In another project, you can now install the beta from the local image you just created by running:
npm install /path/to/tarball
License
Copyright 2023 Fauna, Inc.
Licensed under the Mozilla Public License, Version 2.0 (the "License"); you may
not use this software except in compliance with the License. You may obtain a
copy of the License at
http://mozilla.org/MPL/2.0/
Unless required by applicable law or agreed to in writing, software distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License.