searxng/docs/admin/settings/settings_server.rst

server:

server:
    base_url: http://example.org/location  # change this!
    port: 8888
    bind_address: "127.0.0.1"
    secret_key: "ultrasecretkey"           # change this!
    limiter: false
    image_proxy: false
    default_http_headers:
      X-Content-Type-Options : nosniff
      X-XSS-Protection : 1; mode=block
      X-Download-Options : noopen
      X-Robots-Tag : noindex, nofollow
      Referrer-Policy : no-referrer

base_url : $SEARXNG_URL buildenv <make buildenv>

The base URL where SearXNG is deployed. Used to create correct inbound links. If you change the value, don't forget to rebuild instance's environment (utils/brand.env <make buildenv>)

port & bind_address: $SEARXNG_PORT & $SEARXNG_BIND_ADDRESS buildenv <make buildenv>

Port number and bind address of the SearXNG web application if you run it directly using python searx/webapp.py. Doesn't apply to a SearXNG services running behind a proxy and using socket communications. If you change the value, don't forget to rebuild instance's environment (utils/brand.env <make buildenv>)

secret_key : $SEARXNG_SECRET

Used for cryptography purpose.

limiter :

Rate limit the number of request on the instance, block some bots. The limiter src requires a settings redis database.

image_proxy :

Allow your instance of SearXNG of being able to proxy images. Uses memory space.

default_http_headers :

Set additional HTTP headers, see #755