The Clean language search engine
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The Clean language search engine. Cloogle lets you search for functions, types, classes and modules from Clean libraries. It also has documentation for language features, common compiler errors and ABC instructions. The web app is available at

Cloogle was inspired by Hoogle. As of June 27, 2018, Cloogle indexes 100× less lines of code than Hoogle (25 thousand vs. 2.3 million). This allows Cloogle to implement more advanced features, such as using queries to find usages.

Readme contents


These frontends to Cloogle are currently known to us:

  • The web app at
  • The !cloogle bang on DuckDuckGo.
  • The :Cloogle command or <LocalLeader>cin vim-clean.
  • An email to with the query in the subject (see cloogle-mail).
  • The !query command of the IRC bot clooglebot which often resides on the #cloogle and #cleanlang channels on freenode (see clean-irc).

Old frontends:

Auxiliary tools

Several tools used in Cloogle are available as separate libraries from Additionally, these tools can be helpful:

Cloogle-tags: This program lets you index local Clean code in tagfiles that can be used by your text editor.

Library browser: The frontend includes a library browser to browse through all known Clean libraries. The browser can be accessed through

Documentation browser: There is also an HTML version of the Clean Language Report, available at

Logging: A websocket server on port 31216 provides the realtime log.

Statistics: On, a realtime usage chart is shown. For longterm statistics you can see

Interfacing with Cloogle

CloogleServer is a TCP server listening on port 31215 (typically). Send a JSON request in the format described by the Request type in Cloogle.dcl, followed by a newline character. The response is in the format described by the Response type. The connection is kept alive for some time to allow further requests.

To interface with Cloogle, it is recommended that you use the HTTP API rather than the TCP API.

For a Clean interface to Cloogle, it is suggested that you use libcloogle.

For a Python interface to Cloogle, you can use

The HTTP API is a simple wrapper around the TCP API, with a more stable API. api.php should be called with a GET request where the str parameter contains the search string. You may also add mod (a comma-separated list of modules to search in) and page (for pagination: 0 for the first n results, 1 for the next n, etc.). For the query syntax in the str parameter, see the 'How to use' guidelines on

The API returns the same JSON as the TCP API, but may include additional results when searched for Clean error messages (for example, stack overflow). These error messages are indexed by the frontend rather than the backend. Additionally, the HTTP API may give return codes above 150, which are not used by the TCP API. For the meaning of the return codes, see Cloogle.icl.

Preparing a library for indexing

Your library will be most easily accessible when:

  • Functions, type definitions, classes and modules are documented. For details on the documentation format, see the README of the Cloogle submodule.
  • Macros have types using the @type documentation field.

Having documentation is not a strict requirement, however. To add your library to the index, follow the steps in and create a pull request.

Local setup

After installing docker-compose run the following commands:

touch cloogle.log
sudo docker-compose up

Your Cloogle server now runs at port 31215 on your local machine. The web frontend is available at port 80, live statistics at port 31216.

If you intend to run this on a server that has port 80 occupied already, you can use nginx or apache2 as a proxy. Change 80:80 to 31280:80 in docker-compose.yml and use the following nginx config:

server {
	listen [::]:80;

	location / {
		proxy_set_header Host $host;
		proxy_set_header X-Forwarded-For $remote_addr;

Or the following apache2 virtualhost (be sure to enable mod_proxy).

<VirtualHost *:80>

	ProxyRequests off
	ProxyPass / http://localhost:31280/
	ProxyPassReverse / http://localhost:31280/

Authors, copyright & license

Copyright © 2016-present Mart Lubbers and Camil Staps. Licensed under MIT; See the LICENSE file.