API Reference

This is a mostly auto-generated API. If you are new to bottle, you might find the narrative Tutorial more helpful.

Module Contents

The module defines several functions, constants, and an exception.


Change the debug level. There is only one debug level supported at the moment.

run(app=None, server='wsgiref', host='', port=8080, interval=1, reloader=False, quiet=False, plugins=None, debug=None, **kargs)[source]

Start a server instance. This method blocks until the server terminates.

  • app – WSGI application or target string supported by load_app(). (default: default_app())
  • server – Server adapter to use. See server_names keys for valid names or pass a ServerAdapter subclass. (default: wsgiref)
  • host – Server address to bind to. Pass to listens on all interfaces including the external one. (default:
  • port – Server port to bind to. Values below 1024 require root privileges. (default: 8080)
  • reloader – Start auto-reloading server? (default: False)
  • interval – Auto-reloader interval in seconds (default: 1)
  • quiet – Suppress output to stdout and stderr? (default: False)
  • options – Options passed to the server adapter.
load(target, **namespace)[source]

Import a module or fetch an object from a module.

  • package.module returns module as a module object.
  • pack.mod:name returns the module variable name from pack.mod.
  • pack.mod:func() calls pack.mod.func() and returns the result.

The last form accepts not only function calls, but any type of expression. Keyword arguments passed to this function are available as local variables. Example: import_string('re:compile(x)', x='[a-z]')


Load a bottle application from a module and make sure that the import does not affect the current default application, but returns a separate application object. See load() for the target parameter.

request = <LocalRequest: GET>

A thread-safe instance of LocalRequest. If accessed from within a request callback, this instance always refers to the current request (even on a multithreaded server).

response = Content-Type: text/html; charset=UTF-8

A thread-safe instance of LocalResponse. It is used to change the HTTP response for the current request.

HTTP_CODES = {300: 'Multiple Choices', 301: 'Moved Permanently', 302: 'Found', 303: 'See Other', 304: 'Not Modified', 305: 'Use Proxy', 306: '(Unused)', 307: 'Temporary Redirect', 100: 'Continue', 101: 'Switching Protocols', 400: 'Bad Request', 401: 'Unauthorized', 402: 'Payment Required', 403: 'Forbidden', 404: 'Not Found', 405: 'Method Not Allowed', 406: 'Not Acceptable', 407: 'Proxy Authentication Required', 408: 'Request Timeout', 409: 'Conflict', 410: 'Gone', 411: 'Length Required', 412: 'Precondition Failed', 413: 'Request Entity Too Large', 414: 'Request-URI Too Long', 415: 'Unsupported Media Type', 416: 'Requested Range Not Satisfiable', 417: 'Expectation Failed', 418: "I'm a teapot", 428: 'Precondition Required', 429: 'Too Many Requests', 431: 'Request Header Fields Too Large', 200: 'OK', 201: 'Created', 202: 'Accepted', 203: 'Non-Authoritative Information', 204: 'No Content', 205: 'Reset Content', 206: 'Partial Content', 500: 'Internal Server Error', 501: 'Not Implemented', 502: 'Bad Gateway', 503: 'Service Unavailable', 504: 'Gateway Timeout', 505: 'HTTP Version Not Supported', 511: 'Network Authentication Required'}

A dict to map HTTP status codes (e.g. 404) to phrases (e.g. ‘Not Found’)


Return the current Default Application. Actually, these are callable instances of AppStack and implement a stack-like API.


Bottle maintains a stack of Bottle instances (see app() and AppStack) and uses the top of the stack as a default application for some of the module-level functions and decorators.

route(path, method='GET', callback=None, **options)

Decorator to install a route to the current default application. See Bottle.route() for details.


Decorator to install an error handler to the current default application. See Bottle.error() for details.

WSGI and HTTP Utilities


Parse rfc1123, rfc850 and asctime timestamps and return UTC epoch.


Parse rfc2617 HTTP authentication header string (basic) and return (user,pass) tuple or None

cookie_encode(data, key)[source]

Encode and sign a pickle-able object. Return a (byte) string

cookie_decode(data, key)[source]

Verify and decode an encoded string. Return an object or None.


Return True if the argument looks like a encoded cookie.


Return a generator for routes that match the signature (name, args) of the func parameter. This may yield more than one route if the function takes optional keyword arguments. The output is best described by example:

a()         -> '/a'
b(x, y)     -> '/b/<x>/<y>'
c(x, y=5)   -> '/c/<x>' and '/c/<x>/<y>'
d(x=5, y=6) -> '/d' and '/d/<x>' and '/d/<x>/<y>'
path_shift(script_name, path_info, shift=1)[source]

Shift path fragments from PATH_INFO to SCRIPT_NAME and vice versa.


The modified paths.

  • script_name – The SCRIPT_NAME path.
  • script_name – The PATH_INFO path.
  • shift – The number of path fragments to shift. May be negative to change the shift direction. (default: 1)

Data Structures

class MultiDict(*a, **k)[source]

This dict stores multiple values per key, but behaves exactly like a normal dict in that it returns only the newest value for any given key. There are special methods available to access the full list of values.

get(key, default=None, index=-1, type=None)[source]

Return the most recent value for a key.

  • default – The default value to be returned if the key is not present or the type conversion fails.
  • index – An index for the list of available values.
  • type – If defined, this callable is used to cast the value into a specific type. Exception are suppressed and result in the default value to be returned.
append(key, value)[source]

Add a new value to the list of values for this key.

replace(key, value)[source]

Replace the list of values with a single value.


Return a (possibly empty) list of values for a key.

getone(key, default=None, index=-1, type=None)

Aliases for WTForms to mimic other multi-dict APIs (Django)


Return a (possibly empty) list of values for a key.

class HeaderDict(*a, **ka)[source]

A case-insensitive version of MultiDict that defaults to replace the old value instead of appending it.

class FormsDict(*a, **k)[source]

This MultiDict subclass is used to store request form data. Additionally to the normal dict-like item access methods (which return unmodified data as native strings), this container also supports attribute-like access to its values. Attributes are automatically de- or recoded to match input_encoding (default: ‘utf8’). Missing attributes default to an empty string.

input_encoding = 'utf8'

Encoding used for attribute values.

recode_unicode = True

If true (default), unicode strings are first encoded with latin1 and then decoded to match input_encoding.


Returns a copy with all keys and values de- or recoded to match input_encoding. Some libraries (e.g. WTForms) want a unicode dictionary.

getunicode(name, default=None, encoding=None)[source]

Return the value as a unicode string, or the default.

class WSGIHeaderDict(environ)[source]

This dict-like class wraps a WSGI environ dict and provides convenient access to HTTP_* fields. Keys and values are native strings (2.x bytes or 3.x unicode) and keys are case-insensitive. If the WSGI environment contains non-native string values, these are de- or encoded using a lossless ‘latin1’ character set.

The API will remain stable even on changes to the relevant PEPs. Currently PEP 333, 444 and 3333 are supported. (PEP 444 is the only one that uses non-native strings.)


List of keys that do not have a HTTP_ prefix.

raw(key, default=None)[source]

Return the header value as is (may be bytes or unicode).

class AppStack[source]

A stack-like list. Calling it returns the head of the stack.


Return the current default application and remove it from the stack.


Add a new Bottle instance to the stack

class ResourceManager(base='./', opener=<built-in function open>, cachemode='all')[source]

This class manages a list of search paths and helps to find and open application-bound resources (files).

  • base – default value for add_path() calls.
  • opener – callable used to open resources.
  • cachemode – controls which lookups are cached. One of ‘all’, ‘found’ or ‘none’.
path = None

A list of search paths. See add_path() for details.

cache = None

A cache for resolved paths. res.cache.clear() clears the cache.

add_path(path, base=None, index=None, create=False)[source]

Add a new path to the list of search paths. Return False if the path does not exist.

  • path – The new search path. Relative paths are turned into an absolute and normalized form. If the path looks like a file (not ending in /), the filename is stripped off.
  • base – Path used to absolutize relative search paths. Defaults to base which defaults to os.getcwd().
  • index – Position within the list of search paths. Defaults to last index (appends to the list).

The base parameter makes it easy to reference files installed along with a python module or package:

res.add_path('./resources/', __file__)

Search for a resource and return an absolute file path, or None.

The path list is searched in order. The first match is returend. Symlinks are followed. The result is cached to speed up future lookups.

open(name, mode='r', *args, **kwargs)[source]

Find a resource and return a file object, or raise IOError.

class FileUpload(fileobj, name, filename, headers=None)[source]
file = None

Open file(-like) object (BytesIO buffer or temporary file)

name = None

Name of the upload form field

raw_filename = None

Raw filename as sent by the client (may contain unsafe characters)

headers = None

A HeaderDict with additional headers (e.g. content-type)


Current value of the ‘Content-Type’ header.


Current value of the ‘Content-Length’ header.


Name of the file on the client file system, but normalized to ensure file system compatibility (lowercase, no whitespace, no path separators, no unsafe characters, ASCII only). An empty filename is returned as ‘empty’.

save(destination, overwrite=False, chunk_size=65536)[source]

Save file to disk or copy its content to an open file(-like) object. If destination is a directory, filename is added to the path. Existing files are not overwritten by default (IOError).

  • destination – File path, directory or file(-like) object.
  • overwrite – If True, replace existing files. (default: False)
  • chunk_size – Bytes to read at a time. (default: 64kb)


exception BottleException[source]

A base class for exceptions used by bottle.

The Bottle Class

class Bottle(catchall=True, autojson=True)[source]

Each Bottle object represents a single, distinct web application and consists of routes, callbacks, plugins, resources and configuration. Instances are callable WSGI applications.

Parameters:catchall – If true (default), handle all exceptions. Turn off to let debugging middleware handle exceptions.
config = None

A ConfigDict for app specific configuration.

resources = None

A ResourceManager for application files


If true, most exceptions are caught and returned as HTTPError

add_hook(name, func)[source]

Attach a callback to a hook. Three hooks are currently implemented:

Executed once before each request. The request context is available, but no routing has happened yet.
Executed once after each request regardless of its outcome.
Called whenever Bottle.reset() is called.
remove_hook(name, func)[source]

Remove a callback from a hook.

trigger_hook(_Bottle__name, *args, **kwargs)[source]

Trigger a hook and return a list of results.


Return a decorator that attaches a callback to a hook. See add_hook() for details.

mount(prefix, app, **options)[source]

Mount an application (Bottle or plain WSGI) to a specific URL prefix. Example:

root_app.mount('/admin/', admin_app)
  • prefix – path prefix or mount-point. If it ends in a slash, that slash is mandatory.
  • app – an instance of Bottle or a WSGI application.

All other parameters are passed to the underlying route() call.


Merge the routes of another Bottle application or a list of Route objects into this application. The routes keep their ‘owner’, meaning that the Route.app attribute is not changed.


Add a plugin to the list of plugins and prepare it for being applied to all routes of this application. A plugin may be a simple decorator or an object that implements the Plugin API.


Uninstall plugins. Pass an instance to remove a specific plugin, a type object to remove all plugins that match that type, a string to remove all plugins with a matching name attribute or True to remove all plugins. Return the list of removed plugins.


Reset all routes (force plugins to be re-applied) and clear all caches. If an ID or route object is given, only that specific route is affected.


Close the application and all installed plugins.


Calls run() with the same parameters.


Search for a matching route and return a (Route , urlargs) tuple. The second value is a dictionary with parameters extracted from the URL. Raise HTTPError (404/405) on a non-match.

get_url(routename, **kargs)[source]

Return a string that matches a named route


Add a route object, but do not change the Route.app attribute.

route(path=None, method='GET', callback=None, name=None, apply=None, skip=None, **config)[source]

A decorator to bind a function to a request URL. Example:

def hello(name):
    return 'Hello %s' % name

The :name part is a wildcard. See Router for syntax details.

  • path – Request path or a list of paths to listen to. If no path is specified, it is automatically generated from the signature of the function.
  • method – HTTP method (GET, POST, PUT, ...) or a list of methods to listen to. (default: GET)
  • callback – An optional shortcut to avoid the decorator syntax. route(..., callback=func) equals route(...)(func)
  • name – The name for this route. (default: None)
  • apply – A decorator or plugin or a list of plugins. These are applied to the route callback in addition to installed plugins.
  • skip – A list of plugins, plugin classes or names. Matching plugins are not installed to this route. True skips all.

Any additional keyword arguments are stored as route-specific configuration and passed to plugins (see Plugin.apply()).

get(path=None, method='GET', **options)[source]

Equals route().

post(path=None, method='POST', **options)[source]

Equals route() with a POST method parameter.

put(path=None, method='PUT', **options)[source]

Equals route() with a PUT method parameter.

delete(path=None, method='DELETE', **options)[source]

Equals route() with a DELETE method parameter.


Decorator: Register an output handler for a HTTP error code

wsgi(environ, start_response)[source]

The bottle WSGI-interface.

class Route(app, rule, method, callback, name=None, plugins=None, skiplist=None, **config)[source]

This class wraps a route callback along with route specific metadata and configuration and applies Plugins on demand. It is also responsible for turing an URL path rule into a regular expression usable by the Router.

app = None

The application this route is installed to.

rule = None

The path-rule string (e.g. /wiki/:page).

method = None

The HTTP method as a string (e.g. GET).

callback = None

The original callback with no plugins applied. Useful for introspection.

name = None

The name of the route (if specified) or None.

plugins = None

A list of route-specific plugins (see Bottle.route()).

skiplist = None

A list of plugins to not apply to this route (see Bottle.route()).

config = None

Additional keyword arguments passed to the Bottle.route() decorator are stored in this dictionary. Used for route-specific plugin configuration and meta-data.


The route callback with all plugins applied. This property is created on demand and then cached to speed up subsequent requests.


Forget any cached values. The next time call is accessed, all plugins are re-applied.


Do all on-demand work immediately (useful for debugging).


Yield all Plugins affecting this route.


Return the callback. If the callback is a decorated function, try to recover the original function.


Return a list of argument names the callback (most likely) accepts as keyword arguments. If the callback is a decorated function, try to recover the original function before inspection.

get_config(key, default=None)[source]

Lookup a config field and return its value, first checking the route.config, then route.app.config.

The Request Object

The Request class wraps a WSGI environment and provides helpful methods to parse and access form data, cookies, file uploads and other metadata. Most of the attributes are read-only.


alias of BaseRequest

class BaseRequest(environ=None)[source]

A wrapper for WSGI environment dictionaries that adds a lot of convenient access methods and properties. Most of them are read-only.

Adding new attributes to a request actually adds them to the environ dictionary (as ‘bottle.request.ext.<name>’). This is the recommended way to store and access request-specific data.

MEMFILE_MAX = 102400

Maximum size of memory buffer for body in bytes.


The wrapped WSGI environ dictionary. This is the only real attribute. All other attributes actually are read-only properties.


Bottle application handling this request.


The bottle Route object that matches this request.


The arguments extracted from the URL.


The value of PATH_INFO with exactly one prefixed slash (to fix broken clients and avoid the “empty path” edge case).


The REQUEST_METHOD value as an uppercase string.


A WSGIHeaderDict that provides case-insensitive access to HTTP request headers.

get_header(name, default=None)[source]

Return the value of a request header, or a given default value.


Cookies parsed into a FormsDict. Signed cookies are NOT decoded. Use get_cookie() if you expect signed cookies.

Return the content of a cookie. To read a Signed Cookie, the secret must match the one used to create the cookie (see BaseResponse.set_cookie()). If anything goes wrong (missing cookie or wrong signature), return a default value.


The query_string parsed into a FormsDict. These values are sometimes called “URL arguments” or “GET parameters”, but not to be confused with “URL wildcards” as they are provided by the Router.


Form values parsed from an url-encoded or multipart/form-data encoded POST or PUT request body. The result is returned as a FormsDict. All keys and values are strings. File uploads are stored separately in files.


A FormsDict with the combined values of query and forms. File uploads are stored in files.


File uploads parsed from multipart/form-data encoded POST or PUT request body. The values are instances of FileUpload.


If the Content-Type header is application/json, this property holds the parsed content of the request body. Only requests smaller than MEMFILE_MAX are processed to avoid memory exhaustion.


The HTTP request body as a seek-able file-like object. Depending on MEMFILE_MAX, this is either a temporary file or a io.BytesIO instance. Accessing this property for the first time reads and replaces the wsgi.input environ variable. Subsequent accesses just do a seek(0) on the file object.


True if Chunked transfer encoding was.


An alias for query.


The values of forms and files combined into a single FormsDict. Values are either strings (form values) or instances of cgi.FieldStorage (file uploads).


The full request URI including hostname and scheme. If your app lives behind a reverse proxy or load balancer and you get confusing results, make sure that the X-Forwarded-Host header is set correctly.


The url string as an urlparse.SplitResult tuple. The tuple contains (scheme, host, path, query_string and fragment), but the fragment is always empty because it is not visible to the server.


Request path including script_name (if present).


The raw query part of the URL (everything in between ? and #) as a string.


The initial portion of the URL’s path that was removed by a higher level (server or routing middleware) before the application was called. This script path is returned with leading and tailing slashes.

Shift path segments from path to script_name and
vice versa.
Parameters:shift – The number of path segments to shift. May be negative to change the shift direction. (default: 1)

The request body length as an integer. The client is responsible to set this header. Otherwise, the real length of the body is unknown and -1 is returned. In this case, body will be empty.


The Content-Type header as a lowercase-string (default: empty).


True if the request was triggered by a XMLHttpRequest. This only works with JavaScript libraries that support the X-Requested-With header (most of the popular libraries do).


Alias for is_xhr. “Ajax” is not the right term.


HTTP authentication data as a (user, password) tuple. This implementation currently supports basic (not digest) authentication only. If the authentication happened at a higher level (e.g. in the front web-server or a middleware), the password field is None, but the user field is looked up from the REMOTE_USER environ variable. On any errors, None is returned.


A list of all IPs that were involved in this request, starting with the client IP and followed by zero or more proxies. This does only work if all proxies support the `X-Forwarded-For header. Note that this information can be forged by malicious clients.


The client IP as a string. Note that this information can be forged by malicious clients.


Return a new Request with a shallow environ copy.

The module-level bottle.request is a proxy object (implemented in LocalRequest) and always refers to the current request, or in other words, the request that is currently processed by the request handler in the current thread. This thread locality ensures that you can safely use a global instance in a multi-threaded environment.

class LocalRequest(environ=None)[source]

A thread-local subclass of BaseRequest with a different set of attributes for each thread. There is usually only one global instance of this class (request). If accessed during a request/response cycle, this instance always refers to the current request (even on a multithreaded server).


Wrap a WSGI environ dictionary.


Thread-local property

request = <LocalRequest: GET>

A thread-safe instance of LocalRequest. If accessed from within a request callback, this instance always refers to the current request (even on a multithreaded server).

The Response Object

The Response class stores the HTTP status code as well as headers and cookies that are to be sent to the client. Similar to bottle.request there is a thread-local bottle.response instance that can be used to adjust the current response. Moreover, you can instantiate Response and return it from your request handler. In this case, the custom instance overrules the headers and cookies defined in the global one.


alias of BaseResponse

class BaseResponse(body='', status=None, headers=None, **more_headers)[source]

Storage class for a response body as well as headers and cookies.

This class does support dict-like case-insensitive item-access to headers, but is NOT a dict. Most notably, iterating over a response yields parts of the body and not the headers.

  • body – The response body as one of the supported types.
  • status – Either an HTTP status code (e.g. 200) or a status line including the reason phrase (e.g. ‘200 OK’).
  • headers – A dictionary or a list of name-value pairs.

Additional keyword arguments are added to the list of headers. Underscores in the header name are replaced with dashes.


Returns a copy of self.


The HTTP status line as a string (e.g. 404 Not Found).


The HTTP status code as an integer (e.g. 404).


A writeable property to change the HTTP response status. It accepts either a numeric code (100-999) or a string with a custom reason phrase (e.g. “404 Brain not found”). Both status_line and status_code are updated accordingly. The return value is always a status string.


An instance of HeaderDict, a case-insensitive dict-like view on the response headers.

get_header(name, default=None)[source]

Return the value of a previously defined header. If there is no header with that name, return a default value.

set_header(name, value)[source]

Create a new response header, replacing any previously defined headers with the same name.

add_header(name, value)[source]

Add an additional response header, not removing duplicates.


Yield (header, value) tuples, skipping headers that are not allowed with the current response status code.


WSGI conform list of (header, value) tuples.


Current value of the ‘Content-Type’ header.


Current value of the ‘Content-Length’ header.


Current value of the ‘Expires’ header.


Return the charset specified in the content-type header (default: utf8).

Create a new cookie or replace an old one. If the secret parameter is set, create a Signed Cookie (described below).

  • name – the name of the cookie.
  • value – the value of the cookie.
  • secret – a signature key required for signed cookies.

Additionally, this method accepts all RFC 2109 attributes that are supported by cookie.Morsel, including:

  • max_age – maximum age in seconds. (default: None)
  • expires – a datetime object or UNIX timestamp. (default: None)
  • domain – the domain that is allowed to read the cookie. (default: current domain)
  • path – limits the cookie to a given path (default: current path)
  • secure – limit the cookie to HTTPS connections (default: off).
  • httponly – prevents client-side javascript to read this cookie (default: off, requires Python 2.6 or newer).

If neither expires nor max_age is set (default), the cookie will expire at the end of the browser session (as soon as the browser window is closed).

Signed cookies may store any pickle-able object and are cryptographically signed to prevent manipulation. Keep in mind that cookies are limited to 4kb in most browsers.

Warning: Signed cookies are not encrypted (the client can still see the content) and not copy-protected (the client can restore an old cookie). The main intention is to make pickling and unpickling save, not to store secret information at client side.

Delete a cookie. Be sure to use the same domain and path settings as used to create the cookie.

class LocalResponse(body='', status=None, headers=None, **more_headers)[source]

A thread-local subclass of BaseResponse with a different set of attributes for each thread. There is usually only one global instance of this class (response). Its attributes are used to build the HTTP response at the end of the request/response cycle.


Thread-local property

The following two classes can be raised as an exception. The most noticeable difference is that bottle invokes error handlers for HTTPError, but not for HTTPResponse or other response types.

exception HTTPResponse(body='', status=None, headers=None, **more_headers)[source]
exception HTTPError(status=None, body=None, exception=None, traceback=None, **options)[source]


All template engines supported by bottle implement the BaseTemplate API. This way it is possible to switch and mix template engines without changing the application code at all.

class BaseTemplate(source=None, name=None, lookup=, []encoding='utf8', **settings)[source]

Base class and minimal API for template adapters

__init__(source=None, name=None, lookup=, []encoding='utf8', **settings)[source]

Create a new template. If the source parameter (str or buffer) is missing, the name argument is used to guess a template filename. Subclasses can assume that self.source and/or self.filename are set. Both are strings. The lookup, encoding and settings parameters are stored as instance variables. The lookup parameter stores a list containing directory paths. The encoding parameter should be used to decode byte strings or files. The settings parameter contains a dict for engine-specific settings.

classmethod search(name, lookup=[])[source]

Search name in all directories specified in lookup. First without, then with common extensions. Return first hit.

classmethod global_config(key, *args)[source]

This reads or sets the global settings stored in class.settings.


Run preparations (parsing, caching, ...). It should be possible to call this again to refresh a template or to update settings.

render(*args, **kwargs)[source]

Render the template with the specified local variables and return a single byte or unicode string. If it is a byte string, the encoding must match self.encoding. This method must be thread-safe! Local variables may be provided in dictionaries (args) or directly, as keywords (kwargs).

view(tpl_name, **defaults)[source]

Decorator: renders a template for a handler. The handler can control its behavior like that:

  • return a dict of template vars to fill out the template
  • return something other than a dict and the view decorator will not process the template, but return the handler result as is. This includes returning a HTTPResponse(dict) to get, for instance, JSON with autojson or other castfilters.
template(*args, **kwargs)[source]

Get a rendered template as a string iterator. You can use a name, a filename or a template string as first parameter. Template rendering arguments can be passed as dictionaries or directly (as keyword arguments).

You can write your own adapter for your favourite template engine or use one of the predefined adapters. Currently there are four fully supported template engines:

Class URL Decorator Render function
SimpleTemplate SimpleTemplate Engine view() template()
MakoTemplate http://www.makotemplates.org mako_view() mako_template()
CheetahTemplate http://www.cheetahtemplate.org/ cheetah_view() cheetah_template()
Jinja2Template http://jinja.pocoo.org/ jinja2_view() jinja2_template()

To use MakoTemplate as your default template engine, just import its specialised decorator and render function:

from bottle import mako_view as view, mako_template as template

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