Engine Overview

SearXNG is a metasearch-engine, so it uses different search engines to provide better results.

Because there is no general search API which could be used for every search engine, an adapter has to be built between SearXNG and the external search engines. Adapters are stored under the folder git://searx/engines.

General Engine Configuration

It is required to tell SearXNG the type of results the engine provides. The arguments can be set in the engine file or in the settings file (normally settings.yml). The arguments in the settings file override the ones in the engine file.

It does not matter if an option is stored in the engine file or in the settings. However, the standard way is the following:

Engine File

Table 2 Common options in the engine module

argument

type

information

categories

list

pages, in which the engine is working

paging

boolean

support multiple pages

time_range_support

boolean

support search time range

engine_type

str

  • online [ref] by default, other possibles values are:

  • offline [ref]

  • online_dictionary

  • online_currency

  • online_url_search

Engine settings.yml

For a more detailed description, see Engine settings in the settings.yml.

Table 3 Common options in the engine setup (settings.yml)

argument

type

information

name

string

name of search-engine

engine

string

name of searxng-engine (file name without .py)

enable_http

bool

enable HTTP (by default only HTTPS is enabled).

shortcut

string

shortcut of search-engine

timeout

string

specific timeout for search-engine

display_error_messages

boolean

display error messages on the web UI

proxies

dict

set proxies for a specific engine (e.g. proxies : {http: socks5://proxy:port, https: socks5://proxy:port})

Overrides

A few of the options have default values in the namespace of engine’s python modul, but are often overwritten by the settings. If None is assigned to an option in the engine file, it has to be redefined in the settings, otherwise SearXNG will not start with that engine (global names with a leading underline can be None).

Here is an very simple example of the global names in the namespace of engine’s module:

# engine dependent config
categories = ['general']
paging = True
_non_overwritten_global = 'foo'
Table 4 The naming of overrides is arbitrary / recommended overrides are:

argument

type

information

base_url

string

base-url, can be overwritten to use same engine on other URL

number_of_results

int

maximum number of results per request

language

string

ISO code of language and country like en_US

api_key

string

api-key if required by engine

Making a Request

To perform a search an URL have to be specified. In addition to specifying an URL, arguments can be passed to the query.

Passed Arguments (request)

These arguments can be used to construct the search query. Furthermore, parameters with default value can be redefined for special purposes.

Table 5 If the engine_type is online

argument

type

default-value, information

url

str

''

method

str

'GET'

headers

set

{}

data

set

{}

cookies

set

{}

verify

bool

True

headers.User-Agent

str

a random User-Agent

category

str

current category, like 'general'

safesearch

int

0, between 0 and 2 (normal, moderate, strict)

time_range

Optional[str]

None, can be day, week, month, year

pageno

int

current pagenumber

searxng_locale

str

SearXNG’s locale selected by user. Specific language code like 'en', 'en-US', or 'all' if unspecified.

Table 6 If the engine_type is online_dictionary, in addition to the online arguments:

argument

type

default-value, information

from_lang

str

specific language code like 'en_US'

to_lang

str

specific language code like 'en_US'

query

str

the text query without the languages

Table 7 If the engine_type is online_currency, in addition to the online arguments:

argument

type

default-value, information

amount

float

the amount to convert

from

str

ISO 4217 code

to

str

ISO 4217 code

from_name

str

currency name

to_name

str

currency name

Table 8 If the engine_type is online_url_search, in addition to the online arguments:

argument

type

default-value, information

search_url

dict

URLs from the search query:

{
  'http': str,
  'ftp': str,
  'data:image': str
}

Specify Request

The function def request(query, params): always returns the params variable, the following parameters can be used to specify a search request:

argument

type

information

url

str

requested url

method

str

HTTP request method

headers

set

HTTP header information

data

set

HTTP data information

cookies

set

HTTP cookies

verify

bool

Performing SSL-Validity check

allow_redirects

bool

Follow redirects

max_redirects

int

maximum redirects, hard limit

soft_max_redirects

int

maximum redirects, soft limit. Record an error but don’t stop the engine

raise_for_httperror

bool

True by default: raise an exception if the HTTP code of response is >= 300

Media Types

Each result item of an engine can be of different media-types. Currently the following media-types are supported. To set another media-type as default, the parameter template must be set to the desired type.

Table 9 Parameter of the default media type:

result-parameter

information

url

string, url of the result

title

string, title of the result

content

string, general result-text

publishedDate

datetime.datetime, time of publish

Table 10 Parameter of the images media type:

result-parameter

information

template

is set to images.html

url

string, url to the result site

title

string, title of the result (partly implemented)

content

(partly implemented)

publishedDate

datetime.datetime, time of publish (partly implemented)

img_src

string, url to the result image

thumbnail_src

string, url to a small-preview image

Table 11 Parameter of the videos media type:

result-parameter

information

template

is set to videos.html

url

string, url of the result

title

string, title of the result

content

(not implemented yet)

publishedDate

datetime.datetime, time of publish

thumbnail

string, url to a small-preview image

Table 12 Parameter of the torrent media type:

result-parameter

information

template

is set to torrent.html

url

string, url of the result

title

string, title of the result

content

string, general result-text

publishedDate

datetime.datetime, time of publish (not implemented yet)

seed

int, number of seeder

leech

int, number of leecher

filesize

int, size of file in bytes

files

int, number of files

magnetlink

string, magnetlink of the result

torrentfile

string, torrentfile of the result

Table 13 Parameter of the map media type:

result-parameter

information

template

is set to map.html

url

string, url of the result

title

string, title of the result

content

string, general result-text

publishedDate

datetime.datetime, time of publish

latitude

latitude of result (in decimal format)

longitude

longitude of result (in decimal format)

boundingbox

boundingbox of result (array of 4. values [lat-min, lat-max, lon-min, lon-max])

geojson

geojson of result (https://geojson.org/)

osm.type

type of osm-object (if OSM-Result)

osm.id

id of osm-object (if OSM-Result)

address.name

name of object

address.road

street name of object

address.house_number

house number of object

address.locality

city, place of object

address.postcode

postcode of object

address.country

country of object

Table 14 Parameter of the paper media type / see BibTeX field types and BibTeX format

result-parameter

Python type

information

template

str

is set to paper.html

title

str

title of the result

content

str

abstract

comments

str

free text display in italic below the content

tags

List[str]

free tag list

publishedDate

datetime

last publication date

type

str

short description of medium type, e.g. book, pdf or html

authors

List[str]

list of authors of the work (authors with a “s”)

editor

str

list of editors of a book

publisher

str

name of the publisher

journal

str

name of the journal or magazine the article was published in

volume

str

volume number

pages

str

page range where the article is

number

str

number of the report or the issue number for a journal article

doi

str

DOI number (like 10.1038/d41586-018-07848-2)

issn

List[str]

ISSN number like 1476-4687

isbn

List[str]

ISBN number like 9780201896831

pdf_url

str

URL to the full article, the PDF version

html_url

str

URL to full article, HTML version