Manage browser sessions, cookies, cache, proxy settings, etc.
Process: Main
The session
module can be used to create new Session
objects.
You can also access the session
of existing pages by using the session
property of WebContents
, or from the session
module.
const { BrowserWindow } = require('electron')
let win = new BrowserWindow({ width: 800, height: 600 })
win.loadURL('http://github.com')
const ses = win.webContents.session
console.log(ses.getUserAgent())
The session
module has the following methods:
partition
Stringoptions
Object (optional)cache
Boolean - Whether to enable cache.
Returns Session
- A session instance from partition
string. When there is an existing
Session
with the same partition
, it will be returned; otherwise a new
Session
instance will be created with options
.
If partition
starts with persist:
, the page will use a persistent session
available to all pages in the app with the same partition
. if there is no
persist:
prefix, the page will use an in-memory session. If the partition
is
empty then default session of the app will be returned.
To create a Session
with options
, you have to ensure the Session
with the
partition
has never been used before. There is no way to change the options
of an existing Session
object.
The session
module has the following properties:
A Session
object, the default session object of the app.
Get and set properties of a session.
Process: Main
You can create a Session
object in the session
module:
const { session } = require('electron')
const ses = session.fromPartition('persist:name')
console.log(ses.getUserAgent())
The following events are available on instances of Session
:
Returns:
event
Eventitem
DownloadItemwebContents
WebContents
Emitted when Electron is about to download item
in webContents
.
Calling event.preventDefault()
will cancel the download and item
will not be
available from next tick of the process.
const { session } = require('electron')
session.defaultSession.on('will-download', (event, item, webContents) => {
event.preventDefault()
require('request')(item.getURL(), (data) => {
require('fs').writeFileSync('/somewhere', data)
})
})
The following methods are available on instances of Session
:
Returns Promise<Integer>
- the session's current cache size, in bytes.
Returns Promise<void>
- resolves when the cache clear operation is complete.
Clears the session’s HTTP cache.
options
Object (optional)origin
String (optional) - Should followwindow.location.origin
’s representationscheme://host:port
.storages
String[] (optional) - The types of storages to clear, can contain:appcache
,cookies
,filesystem
,indexdb
,localstorage
,shadercache
,websql
,serviceworkers
,cachestorage
.quotas
String[] (optional) - The types of quotas to clear, can contain:temporary
,persistent
,syncable
.
Returns Promise<void>
- resolves when the storage data has been cleared.
Writes any unwritten DOMStorage data to disk.
config
ObjectpacScript
String - The URL associated with the PAC file.proxyRules
String - Rules indicating which proxies to use.proxyBypassRules
String - Rules indicating which URLs should bypass the proxy settings.
Returns Promise<void>
- Resolves when the proxy setting process is complete.
Sets the proxy settings.
When pacScript
and proxyRules
are provided together, the proxyRules
option is ignored and pacScript
configuration is applied.
The proxyRules
has to follow the rules below:
proxyRules = schemeProxies[";"<schemeProxies>]
schemeProxies = [<urlScheme>"="]<proxyURIList>
urlScheme = "http" | "https" | "ftp" | "socks"
proxyURIList = <proxyURL>[","<proxyURIList>]
proxyURL = [<proxyScheme>"://"]<proxyHost>[":"<proxyPort>]
For example:
http=foopy:80;ftp=foopy2
- Use HTTP proxyfoopy:80
forhttp://
URLs, and HTTP proxyfoopy2:80
forftp://
URLs.foopy:80
- Use HTTP proxyfoopy:80
for all URLs.foopy:80,bar,direct://
- Use HTTP proxyfoopy:80
for all URLs, failing over tobar
iffoopy:80
is unavailable, and after that using no proxy.socks4://foopy
- Use SOCKS v4 proxyfoopy:1080
for all URLs.http=foopy,socks5://bar.com
- Use HTTP proxyfoopy
for http URLs, and fail over to the SOCKS5 proxybar.com
iffoopy
is unavailable.http=foopy,direct://
- Use HTTP proxyfoopy
for http URLs, and use no proxy iffoopy
is unavailable.http=foopy;socks=foopy2
- Use HTTP proxyfoopy
for http URLs, and usesocks4://foopy2
for all other URLs.
The proxyBypassRules
is a comma separated list of rules described below:
-
[ URL_SCHEME "://" ] HOSTNAME_PATTERN [ ":" <port> ]
Match all hostnames that match the pattern HOSTNAME_PATTERN.
Examples: "foobar.com", "foobar.com", ".foobar.com", "*foobar.com:99", "https://x.*.y.com:99"
-
"." HOSTNAME_SUFFIX_PATTERN [ ":" PORT ]
Match a particular domain suffix.
Examples: ".google.com", ".com", "http://.google.com"
-
[ SCHEME "://" ] IP_LITERAL [ ":" PORT ]
Match URLs which are IP address literals.
Examples: "127.0.1", "[0:0::1]", "[::1]", "http://[::1]:99"
-
IP_LITERAL "/" PREFIX_LENGTH_IN_BITS
Match any URL that is to an IP literal that falls between the given range. IP range is specified using CIDR notation.
Examples: "192.168.1.1/16", "fefe:13::abc/33".
-
<local>
Match local addresses. The meaning of
<local>
is whether the host matches one of: "127.0.0.1", "::1", "localhost".
url
URL
Returns Promise<String>
- Resolves with the proxy information for url
.
path
String - The download location.
Sets download saving directory. By default, the download directory will be the
Downloads
under the respective app folder.
options
Objectoffline
Boolean (optional) - Whether to emulate network outage. Defaults to false.latency
Double (optional) - RTT in ms. Defaults to 0 which will disable latency throttling.downloadThroughput
Double (optional) - Download rate in Bps. Defaults to 0 which will disable download throttling.uploadThroughput
Double (optional) - Upload rate in Bps. Defaults to 0 which will disable upload throttling.
Emulates network with the given configuration for the session
.
// To emulate a GPRS connection with 50kbps throughput and 500 ms latency.
window.webContents.session.enableNetworkEmulation({
latency: 500,
downloadThroughput: 6400,
uploadThroughput: 6400
})
// To emulate a network outage.
window.webContents.session.enableNetworkEmulation({ offline: true })
Disables any network emulation already active for the session
. Resets to
the original network configuration.
proc
Functionrequest
Objecthostname
Stringcertificate
CertificateverificationResult
String - Verification result from chromium.errorCode
Integer - Error code.
callback
FunctionverificationResult
Integer - Value can be one of certificate error codes from here. Apart from the certificate error codes, the following special codes can be used.0
- Indicates success and disables Certificate Transparency verification.-2
- Indicates failure.-3
- Uses the verification result from chromium.
Sets the certificate verify proc for session
, the proc
will be called with
proc(request, callback)
whenever a server certificate
verification is requested. Calling callback(0)
accepts the certificate,
calling callback(-2)
rejects it.
Calling setCertificateVerifyProc(null)
will revert back to default certificate
verify proc.
const { BrowserWindow } = require('electron')
let win = new BrowserWindow()
win.webContents.session.setCertificateVerifyProc((request, callback) => {
const { hostname } = request
if (hostname === 'github.com') {
callback(0)
} else {
callback(-2)
}
})
handler
Function | nullwebContents
WebContents - WebContents requesting the permission. Please note that if the request comes from a subframe you should userequestingUrl
to check the request origin.permission
String - Enum of 'media', 'geolocation', 'notifications', 'midiSysex', 'pointerLock', 'fullscreen', 'openExternal'.callback
FunctionpermissionGranted
Boolean - Allow or deny the permission.
details
Object - Some properties are only available on certain permission types.externalURL
String (optional) - The url of theopenExternal
request.mediaTypes
String[] (optional) - The types of media access being requested, elements can bevideo
oraudio
requestingUrl
String - The last URL the requesting frame loadedisMainFrame
Boolean - Whether the frame making the request is the main frame
Sets the handler which can be used to respond to permission requests for the session
.
Calling callback(true)
will allow the permission and callback(false)
will reject it.
To clear the handler, call setPermissionRequestHandler(null)
.
const { session } = require('electron')
session.fromPartition('some-partition').setPermissionRequestHandler((webContents, permission, callback) => {
if (webContents.getURL() === 'some-host' && permission === 'notifications') {
return callback(false) // denied.
}
callback(true)
})
handler
Function | nullwebContents
WebContents - WebContents checking the permission. Please note that if the request comes from a subframe you should userequestingUrl
to check the request origin.permission
String - Enum of 'media'.requestingOrigin
String - The origin URL of the permission checkdetails
Object - Some properties are only available on certain permission types.securityOrigin
String - The security orign of themedia
check.mediaType
String - The type of media access being requested, can bevideo
,audio
orunknown
requestingUrl
String - The last URL the requesting frame loadedisMainFrame
Boolean - Whether the frame making the request is the main frame
Sets the handler which can be used to respond to permission checks for the session
.
Returning true
will allow the permission and false
will reject it.
To clear the handler, call setPermissionCheckHandler(null)
.
const { session } = require('electron')
session.fromPartition('some-partition').setPermissionCheckHandler((webContents, permission) => {
if (webContents.getURL() === 'some-host' && permission === 'notifications') {
return false // denied
}
return true
})
Returns Promise<void>
- Resolves when the operation is complete.
Clears the host resolver cache.
domains
String - A comma-separated list of servers for which integrated authentication is enabled.
Dynamically sets whether to always send credentials for HTTP NTLM or Negotiate authentication.
const { session } = require('electron')
// consider any url ending with `example.com`, `foobar.com`, `baz`
// for integrated authentication.
session.defaultSession.allowNTLMCredentialsForDomains('*example.com, *foobar.com, *baz')
// consider all urls for integrated authentication.
session.defaultSession.allowNTLMCredentialsForDomains('*')
userAgent
StringacceptLanguages
String (optional)
Overrides the userAgent
and acceptLanguages
for this session.
The acceptLanguages
must a comma separated ordered list of language codes, for
example "en-US,fr,de,ko,zh-CN,ja"
.
This doesn't affect existing WebContents
, and each WebContents
can use
webContents.setUserAgent
to override the session-wide user agent.
Returns String
- The user agent for this session.
identifier
String - Valid UUID.
Returns Promise<Buffer>
- resolves with blob data.
options
Objectpath
String - Absolute path of the download.urlChain
String[] - Complete URL chain for the download.mimeType
String (optional)offset
Integer - Start range for the download.length
Integer - Total length of the download.lastModified
String - Last-Modified header value.eTag
String - ETag header value.startTime
Double (optional) - Time when download was started in number of seconds since UNIX epoch.
Allows resuming cancelled
or interrupted
downloads from previous Session
.
The API will generate a DownloadItem that can be accessed with the will-download
event. The DownloadItem will not have any WebContents
associated with it and
the initial state will be interrupted
. The download will start only when the
resume
API is called on the DownloadItem.
options
(RemovePassword | RemoveClientCertificate)
Returns Promise<void>
- resolves when the session’s HTTP authentication cache has been cleared.
preloads
String[] - An array of absolute path to preload scripts
Adds scripts that will be executed on ALL web contents that are associated with
this session just before normal preload
scripts run.
Returns String[]
an array of paths to preload scripts that have been
registered.
The following properties are available on instances of Session
:
A Cookies
object for this session.
A WebRequest
object for this session.
A Protocol
object for this session.
const { app, session } = require('electron')
const path = require('path')
app.on('ready', function () {
const protocol = session.fromPartition('some-partition').protocol
protocol.registerFileProtocol('atom', function (request, callback) {
var url = request.url.substr(7)
callback({ path: path.normalize(`${__dirname}/${url}`) })
}, function (error) {
if (error) console.error('Failed to register protocol')
})
})
A NetLog
object for this session.
const { app, session } = require('electron')
app.on('ready', async function () {
const netLog = session.fromPartition('some-partition').netLog
netLog.startLogging('/path/to/net-log')
// After some network events
const path = await netLog.stopLogging()
console.log('Net-logs written to', path)
})