diff --git a/lib/adamantium/client/mastodon.rb b/lib/adamantium/client/mastodon.rb
new file mode 100644
index 0000000..8022b26
--- /dev/null
+++ b/lib/adamantium/client/mastodon.rb
@@ -0,0 +1,70 @@
+require "httparty"
+require "digest"
+require "tempfile"
+require "open-uri"
+require "dry/monads"
+
+module Adamantium
+  module Client
+    class Mastodon
+      include Dry::Monads[:result]
+      include Deps["settings"]
+
+      def create_post(post:, media_ids:)
+        unless settings.mastodon_token && settings.mastodon_server
+          return Failure(:no_mastodon_credentials)
+        end
+
+        content = if post[:name]
+          "#{post[:name]} — #{settings.micropub_site_url}/post/#{post[:slug]}"
+        else
+          post[:content]
+        end
+
+        tags = post[:category].map { |tag| "##{tag}" }.join(" ")
+        text_with_tags = "#{content} #{tags}"
+
+        key = Digest::MD5.hexdigest text_with_tags
+        mastodon_token = settings.mastodon_token
+        mastodon_server = settings.mastodon_server.split("@").first
+        response = HTTParty.post("#{mastodon_server}api/v1/statuses", {
+          headers: {
+            "Idempotency-Key": key,
+            Authorization: "Bearer #{mastodon_token}"
+          },
+          body: {
+            status: text_with_tags,
+            media_ids: media_ids
+          }
+        })
+
+        if response.code >= 200 && response.code < 300
+          status = JSON.parse(response.body, symbolize_names: true)
+          Success("#{mastodon_server}/#{status[:id]}")
+        else
+          Failure(response.message)
+        end
+      end
+
+      def upload_media(photo:)
+        file = Tempfile.new(SecureRandom.uuid)
+        file.write(URI.open(photo[:value]).read)
+        file.rewind
+        response = HTTParty.post("#{mastodon_server}api/v2/media", {
+          headers: {
+            Authorization: "Bearer #{mastodon_token}"
+          },
+          multipart: true,
+          body: {
+            file: file,
+            description: photo[:alt]
+          }
+        })
+        file.close
+        file.unlink
+
+        JSON.parse(response.body, symbolize_names: true).fetch(:id, nil)
+      end
+    end
+  end
+end