Uncategorized
namespace Deno
The global namespace where Deno specific, non-standard APIs are located.
Classes
The Deno abstraction for reading and writing files.
A custom HttpClient for use with fetch function. This is designed to allow custom certificates or proxies to be used with fetch().
Deno's permission management API.
An EventTarget returned from the Deno.permissions API which can provide updates to any state changes of the permission.
An unsafe function pointer for passing JavaScript functions as C function pointers to foreign function calls.
An unsafe pointer to a function, for calling functions that are not present as symbols.
An unsafe pointer view to a memory location as specified by the pointer value. The UnsafePointerView API follows the standard built in interface DataView for accessing the underlying types at an memory location (numbers, strings and raw bytes).
Creates a presentable WebGPU surface from given window and display handles.
Enums
A enum which defines the seek mode for IO related APIs that support seeking.
Functions
Registers the given function as a listener of the given signal event.
Register a benchmark test which will be run when deno bench is used on the command line and the containing module looks like a bench module.
Change the current working directory to the specified path.
Changes the permission of a specific file/directory of specified path. Ignores the process's umask.
Synchronously changes the permission of a specific file/directory of specified path. Ignores the process's umask.
Change owner of a regular file or directory.
Synchronously change owner of a regular file or directory.
Connects to the hostname (default is "127.0.0.1") and port on the named transport (default is "tcp"), and resolves to the connection (Conn).
Establishes a secure connection over QUIC using a hostname and port. The cert file is optional and if not included Mozilla's root certificates will be used. See also https://github.com/ctz/webpki-roots for specifics.
Establishes a secure connection over TLS (transport layer security) using an optional list of CA certs, hostname (default is "127.0.0.1") and port.
Gets the size of the console as columns/rows.
Copies the contents and permissions of one file to another specified path, by default creating a new file if needed, else overwriting. Fails if target path is a directory or is unwritable.
Synchronously copies the contents and permissions of one file to another specified path, by default creating a new file if needed, else overwriting. Fails if target path is a directory or is unwritable.
Creates a file if none exists or truncates an existing file and resolves to an instance of Deno.FsFile.
Create a custom HttpClient to use with fetch. This is an extension of the web platform Fetch API which allows Deno to use custom TLS CA certificates and connect via a proxy while using fetch().
Creates a file if none exists or truncates an existing file and returns an instance of Deno.FsFile.
Create a cron job that will periodically execute the provided handler callback based on the specified schedule.
Return a string representing the current working directory.
Opens an external dynamic library and registers symbols, making foreign functions available to be called.
Returns the path to the current deno executable.
Exit the Deno process with optional exit code.
Returns the group id of the process on POSIX platforms. Returns null on windows.
Get the hostname of the machine the Deno process is running on.
Converts the input into a string that has the same format as printed by console.log().
Creates newpath as a hard link to oldpath.
Synchronously creates newpath as a hard link to oldpath.
Listen announces on the local transport address.
Listen announces on the local transport address.
Listen announces on the local transport address over TLS (transport layer security).
Returns an array containing the 1, 5, and 15 minute load averages. The load average is a measure of CPU and IO utilization of the last one, five, and 15 minute periods expressed as a fractional number. Zero means there is no load. On Windows, the three values are always the same and represent the current load, not the 1, 5 and 15 minute load averages.
Resolves to a Deno.FileInfo for the specified path. If path is a symlink, information for the symlink will be returned instead of what it points to.
Synchronously returns a Deno.FileInfo for the specified path. If path is a symlink, information for the symlink will be returned instead of what it points to.
Creates a new temporary directory in the default directory for temporary files, unless dir is specified. Other optional options include prefixing and suffixing the directory name with prefix and suffix respectively.
Synchronously creates a new temporary directory in the default directory for temporary files, unless dir is specified. Other optional options include prefixing and suffixing the directory name with prefix and suffix respectively.
Creates a new temporary file in the default directory for temporary files, unless dir is specified.
Synchronously creates a new temporary file in the default directory for temporary files, unless dir is specified.
Returns an object describing the memory usage of the Deno process and the V8 subsystem measured in bytes.
Creates a new directory with the specified path.
Synchronously creates a new directory with the specified path.
Returns an array of the network interface information.
Open a file and resolve to an instance of Deno.FsFile. The file does not need to previously exist if using the create or createNew open options. The caller may have the resulting file automatically closed by the runtime once it's out of scope by declaring the file variable with the using keyword.
Open a new Deno.Kv connection to persist data.
Synchronously open a file and return an instance of Deno.FsFile. The file does not need to previously exist if using the create or createNew open options. The caller may have the resulting file automatically closed by the runtime once it's out of scope by declaring the file variable with the using keyword.
Returns the release version of the Operating System.
Returns the Operating System uptime in number of seconds.
Reads the directory given by path and returns an async iterable of Deno.DirEntry. The order of entries is not guaranteed.
Synchronously reads the directory given by path and returns an iterable of Deno.DirEntry. The order of entries is not guaranteed.
Reads and resolves to the entire contents of a file as an array of bytes. TextDecoder can be used to transform the bytes to string if required. Rejects with an error when reading a directory.
Synchronously reads and returns the entire contents of a file as an array of bytes. TextDecoder can be used to transform the bytes to string if required. Throws an error when reading a directory.
Resolves to the full path destination of the named symbolic link.
Synchronously returns the full path destination of the named symbolic link.
Asynchronously reads and returns the entire contents of a file as an UTF-8 decoded string.
Synchronously reads and returns the entire contents of a file as an UTF-8 decoded string.
Resolves to the absolute normalized path, with symbolic links resolved.
Synchronously returns absolute normalized path, with symbolic links resolved.
Make the timer of the given id block the event loop from finishing.
Removes the named file or directory.
Removes the given signal listener that has been registered with Deno.addSignalListener.
Synchronously removes the named file or directory.
Renames (moves) oldpath to newpath. Paths may be files or directories. If newpath already exists and is not a directory, rename() replaces it. OS-specific restrictions may apply when oldpath and newpath are in different directories.
Synchronously renames (moves) oldpath to newpath. Paths may be files or directories. If newpath already exists and is not a directory, renameSync() replaces it. OS-specific restrictions may apply when oldpath and newpath are in different directories.
Performs DNS resolution against the given query, returning resolved records.
Serves HTTP requests with the given handler.
Spawns a new subprocess, returning a Deno.ChildProcess handle.
Spawns a subprocess, waits for it to finish, and returns the output.
Synchronously spawns a subprocess, waits for it to finish, and returns the output.
Start TLS handshake from an existing connection using an optional list of CA certificates, and hostname (default is "127.0.0.1"). Specifying CA certs is optional. By default the configured root certificates are used. Using this function requires that the other end of the connection is prepared for a TLS handshake.
Resolves to a Deno.FileInfo for the specified path. Will always follow symlinks.
Synchronously returns a Deno.FileInfo for the specified path. Will always follow symlinks.
Creates newpath as a symbolic link to oldpath.
Creates newpath as a symbolic link to oldpath.
Displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the kernel.
Truncates (or extends) the specified file, to reach the specified len. If len is not specified then the entire file contents are truncated.
Synchronously truncates (or extends) the specified file, to reach the specified len. If len is not specified then the entire file contents are truncated.
Returns the user id of the process on POSIX platforms. Returns null on Windows.
Retrieve the process umask. If mask is provided, sets the process umask. This call always returns what the umask was before the call.
Make the timer of the given id not block the event loop from finishing.
Upgrade an incoming HTTP request to a WebSocket.
Upgrade a QUIC connection into a WebTransport instance.
Changes the access (atime) and modification (mtime) times of a file system object referenced by path. Given times are either in seconds (UNIX epoch time) or as Date objects.
Synchronously changes the access (atime) and modification (mtime) times of a file system object referenced by path. Given times are either in seconds (UNIX epoch time) or as Date objects.
Watch for file system events against one or more paths, which can be files or directories. These paths must exist already. One user action (e.g. touch test.file) can generate multiple file system events. Likewise, one user action can result in multiple file paths in one event (e.g. mv old_name.txt new_name.txt).
Write data to the given path, by default creating a new file if needed, else overwriting.
Synchronously write data to the given path, by default creating a new file if needed, else overwriting.
Write string data to the given path, by default creating a new file if needed, else overwriting.
Synchronously write string data to the given path, by default creating a new file if needed, else overwriting.
Interfaces
A check to perform as part of a Deno.AtomicOperation. The check will fail if the versionstamp for the key-value pair in the KV store does not match the given versionstamp. A check with a null versionstamp checks that the key-value pair does not currently exist in the KV store.
Basic authentication credentials to be used with a Deno.Proxy server when specifying Deno.CreateHttpClientOptions.
Context that is passed to a benchmarked function. The instance is shared between iterations of the benchmark. Its methods can be used for example to override of the measured portion of the function.
The interface for defining a benchmark test using Deno.bench.
If Deno.resolveDns is called with "CAA" record type specified, it will resolve with an array of objects with this interface.
Options which can be set when calling Deno.Command.
The interface returned from calling Deno.Command.output or Deno.Command.outputSync which represents the result of spawning the child process.
Options which can be set when connecting via Deno.connect.
Options which can be set when establishing a TLS connection via Deno.connectTls.
The options used when creating a Deno.HttpClient.
CronSchedule is the interface used for JSON format cron schedule.
A generic transport listener for message-oriented protocols.
Information about a directory entry returned from Deno.readDir and Deno.readDirSync.
A dynamic library resource. Use Deno.dlopen to load a dynamic library and return this interface.
The permission descriptor for the allow-env and deny-env permissions, which controls access to being able to read and write to the process environment variables as well as access other information about the environment. The option variable allows scoping the permission to a specific environment variable.
The permission descriptor for the allow-ffi and deny-ffi permissions, which controls access to loading foreign code and interfacing with it via the Foreign Function Interface API available in Deno. The option path allows scoping the permission to a specific path on the host.
Provides information about a file and is returned by Deno.stat, Deno.lstat, Deno.statSync, and Deno.lstatSync or from calling stat() and statSync() on an Deno.FsFile instance.
The interface for a foreign function as defined by its parameter and result types.
A foreign library interface descriptor.
Returned by Deno.watchFs. It is an async iterator yielding up system events. To stop watching the file system by calling .close() method.
The permission descriptor for the allow-import and deny-import permissions, which controls access to importing from remote hosts via the network. The option host allows scoping the permission for outbound connection to a specific host and port.
Option which can be specified when performing Deno.inspect.
Options for listing key-value pairs in a Deno.Kv.
Options which can be set when opening a listener via Deno.listen.
Options which can be set when opening a TLS listener via Deno.listenTls.
Options which can be set when using Deno.makeTempDir, Deno.makeTempDirSync, Deno.makeTempFile, and Deno.makeTempFileSync.
If Deno.resolveDns is called with "MX" record type specified, it will return an array of objects with this interface.
If Deno.resolveDns is called with "NAPTR" record type specified, it will return an array of objects with this interface.
The address of a network connection or listener using an IP-based transport.
The permission descriptor for the allow-net and deny-net permissions, which controls access to opening network ports and connecting to remote hosts via the network. The option host allows scoping the permission for outbound connection to a specific host and port.
The information for a network interface returned from a call to Deno.networkInterfaces.
Options which can be set when doing Deno.open and Deno.openSync.
The interface which defines what event types are supported by PermissionStatus instances.
A non-null pointer, represented as an object at runtime. The object's prototype is null and cannot be changed. The object cannot be assigned to either and is thus entirely read-only.
An incoming connection for which the server has not yet begun its part of the handshake.
The permission descriptor for the allow-read and deny-read permissions, which controls access to reading resources from the local host. The option path allows scoping the permission to a specific path (and if the path is a directory any sub paths).
The permission descriptor for the allow-run and deny-run permissions, which controls access to what sub-processes can be executed by Deno. The option command allows scoping the permission to a specific executable.
Interface that module run with deno serve subcommand must conform to.
Additional information for an HTTP request and its connection.
Options which can be set when calling Deno.serve.
Options that can be passed to Deno.serve to create a server listening on a TCP port.
Options that can be passed to Deno.serve to create a server listening on a Unix domain socket.
Options that can be passed to Deno.serve to create a server listening on a VSOCK socket.
If Deno.resolveDns is called with "SOA" record type specified, it will return an array of objects with this interface.
If Deno.resolveDns is called with "SRV" record type specified, it will return an array of objects with this interface.
Options which can be set when upgrading an existing connection to TLS via Deno.startTls.
The interface for stdout and stderr streams for child process returned from Deno.Command.spawn.
The permission descriptor for the allow-sys and deny-sys permissions, which controls access to sensitive host system information, which malicious code might attempt to exploit. The option kind allows scoping the permission to a specific piece of information.
Information returned from a call to Deno.systemMemoryInfo.
Context that is passed to a testing function, which can be used to either gain information about the current test, or register additional test steps within the current test.
Register a parameterized group of tests. See DenoTest.each.
Options which can be set when calling Deno.TestContext.assertSnapshot.
Provides certified key material from strings. The key material is provided in PEM-format (Privacy Enhanced Mail, https://www.rfc-editor.org/rfc/rfc1422) which can be identified by having -----BEGIN----- and -----END----- markers at the beginning and end of the strings. This type of key is not compatible with DER-format keys which are binary.
Unstable options which can be set when opening a datagram listener via Deno.listenDatagram.
The address of a network connection or listener using a Unix domain socket.
A Unix domain socket stream connection.
Options which can be set when connecting to a Unix domain socket via Deno.connect.
Unstable options which can be set when opening a unixpacket datagram listener via Deno.listenDatagram.
Options which can be set when opening a Unix listener via Deno.listen or Deno.listenDatagram.
Options which can be set when performing a Deno.upgradeWebSocket upgrade of a Request
The address of a network connection or listener using the VSOCK transport for communication between a virtual machine and its host.
A VSOCK stream connection.
Options which can be set when connecting over VSOCK via Deno.connect.
Options which can be set when opening a VSOCK listener via Deno.listen.
The object that is returned from a Deno.upgradeWebSocket request.
The permission descriptor for the allow-write and deny-write permissions, which controls access to writing to resources from the local host. The option path allow scoping the permission to a specific path (and if the path is a directory any sub paths).
Namespaces
Bundle Typescript/Javascript code into a single file.
A set of error constructors that are raised by Deno APIs.
A namespace containing runtime APIs available in Jupyter notebooks.
APIs for working with the OpenTelemetry observability framework. Deno can export traces, metrics, and logs to OpenTelemetry compatible backends via the OTLP protocol.
The webgpu namespace provides additional APIs that the WebGPU specification does not specify.
Type Aliases
The address of a network connection or listener, regardless of transport.
CronScheduleExpression is used as the type of minute, hour, dayOfMonth, month, and dayOfWeek in CronSchedule.
Type conversion for foreign symbol return types.
Type conversion for foreign symbol return types and unsafe callback parameters.
Additional information for FsEvent objects with the "other" kind.
Consistency level of a KV operation.
An optional versioned pair of key and value in a Deno.Kv.
A key to be persisted in a Deno.Kv. A key is a sequence of Deno.KvKeyParts.
A single part of a Deno.KvKey. Parts are ordered lexicographically, first by their type, and within a given type by their value.
A selector that selects the range of data returned by a list operation on a Deno.Kv.
A mutation to a key in a Deno.Kv. A mutation is a combination of a key, a value, and a type. The type determines how the mutation is applied to the key.
All BigInt number types for interfacing with foreign functions.
The native boolean type for interfacing to foreign functions.
The native buffer type for interfacing to foreign functions.
The native function type for interfacing with foreign functions.
All plain number types for interfacing with foreign functions.
The native pointer type for interfacing to foreign functions.
All supported types for interfacing with foreign functions.
The native void type for interfacing with foreign functions.
Permission descriptors which define a permission and can be queried, requested, or revoked.
The name of a privileged feature which needs permission.
Options which define the permissions within a test or worker context.
The current status of the permission:
Pointers are represented either with a PointerObject object or a null if the pointer is null.
The definition for alternative transports (or proxies) in Deno.CreateHttpClientOptions.
The type of the resource record to resolve via DNS using Deno.resolveDns.
A handler for HTTP requests. Consumes a request and returns a response.
Operating signals which can be listened for or sent to sub-processes. What signals and what their standard behaviors are OS dependent.
A utility type that infers a foreign library interface.
A utility type that infers a foreign symbol.
Specialized listener that accepts TCP connections.
Specialized listener that accepts TLS connections.
A utility type for conversion of parameter types of foreign functions.
Type conversion for unsafe callback return types.
Type conversion for foreign symbol parameters and unsafe callback return types.
Specialized listener that accepts Unix connections.
An unsafe callback function.
Specialized listener that accepts VSOCK connections.
Variables
Returns the script arguments to the program.
Information related to the build of the current Deno runtime.
An interface containing methods to interact with the process environment variables.
The exit code for the Deno process.
The URL of the entrypoint module entered from the command-line. It requires read permission to the CWD.
Reflects the NO_COLOR environment variable at program start.
Deno's permission management API.
The current process ID of this instance of the Deno CLI.
The process ID of parent process of this instance of the Deno CLI.
A reference to stderr which can be used to write directly to stderr. It implements the Deno specific Writer, WriterSync, and Closer interfaces as well as provides a WritableStream interface.
A reference to stdin which can be used to read directly from stdin.
A reference to stdout which can be used to write directly to stdout. It implements the Deno specific Writer, WriterSync, and Closer interfaces as well as provides a WritableStream interface.
Register a test which will be run when deno test is used on the command line and the containing module looks like a test module.
Version information related to the current Deno CLI runtime environment.
© 2018–2025 the Deno authors
Licensed under the MIT License.
https://docs.deno.com/api/deno/uncategorized
