mastodon/config/initializers/content_security_policy.rb

# Define an application-wide content security policy
# For further information see the following documentation
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy

# Rails.application.config.content_security_policy do |p|
#   p.default_src :self, :https
#   p.font_src    :self, :https, :data
#   p.img_src     :self, :https, :data
#   p.object_src  :none
#   p.script_src  :self, :https
#   p.style_src   :self, :https, :unsafe_inline
#
#   # Specify URI for violation reports
#   # p.report_uri "/csp-violation-report-endpoint"
# end

# Report CSP violations to a specified URI
# For further information see the following documentation:
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
# Rails.application.config.content_security_policy_report_only = true