FEATURE: Add native Cohere tool support (#655)

Add native Cohere tool support

- Introduce CohereTools class for tool translation and result processing
- Update Command dialect to integrate with CohereTools
- Modify Cohere endpoint to support passing tools and processing tool calls
- Add spec for testing tool triggering with Cohere endpoint

lib/ai_bot/bot.rb

@@ -63,6 +63,8 @@ module DiscourseAi
         llm_kwargs[:temperature] = persona.temperature if persona.temperature
         llm_kwargs[:top_p] = persona.top_p if persona.top_p
 
+        needs_newlines = false
+
         while total_completions <= MAX_COMPLETIONS && ongoing_chain
           tool_found = false
 
@@ -72,11 +74,18 @@ module DiscourseAi
 
               if (tools.present?)
                 tool_found = true
+                # a bit hacky, but extra newlines do no harm
+                if needs_newlines
+                  update_blk.call("\n\n", cancel, nil)
+                  needs_newlines = false
+                end
+
                 tools[0..MAX_TOOLS].each do |tool|
                   process_tool(tool, raw_context, llm, cancel, update_blk, prompt, context)
                   ongoing_chain &&= tool.chain_next_response?
                 end
               else
+                needs_newlines = true
                 update_blk.call(partial, cancel, nil)
               end
             end

lib/completions/dialects/cohere_tools.rb

@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  module Completions
+    module Dialects
+      class CohereTools
+        def initialize(tools)
+          @raw_tools = tools
+        end
+
+        def tool_results(messages)
+          pairs = []
+
+          current_pair = nil
+          messages.each do |msg|
+            if current_pair == nil && msg[:type] == :tool_call
+              current_pair = [msg]
+            elsif current_pair && msg[:type] == :tool
+              current_pair << msg
+              pairs << current_pair
+              current_pair = nil
+            else
+              current_pair = nil
+            end
+          end
+
+          pairs.map do |call, result|
+            params = JSON.parse(call[:content])["arguments"]
+            {
+              call: {
+                name: call[:name] == "search" ? "search_local" : call[:name],
+                parameters: params,
+                generation_id: call[:id],
+              },
+              outputs: [JSON.parse(result[:content])],
+            }
+          end
+        end
+
+        def translated_tools
+          raw_tools.map do |t|
+            tool = t.dup
+
+            tool[:parameter_definitions] = t[:parameters]
+              .to_a
+              .reduce({}) do |memo, p|
+                name = p[:name]
+                memo[name] = {
+                  description: p[:description],
+                  type: cohere_type(p[:type], p[:item_type]),
+                  required: p[:required],
+                }
+
+                memo[name][:default] = p[:default] if p[:default]
+                memo
+              end
+
+            {
+              name: tool[:name] == "search" ? "search_local" : tool[:name],
+              description: tool[:description],
+              parameter_definitions: tool[:parameter_definitions],
+            }
+          end
+        end
+
+        def instructions
+          "" # Noop. Tools are listed separate.
+        end
+
+        private
+
+        attr_reader :raw_tools
+
+        def cohere_type(type, item_type)
+          case type
+          when "string"
+            "str"
+          when "number"
+            item_type == "integer" ? "int" : "float"
+          when "boolean"
+            "bool"
+          when "object"
+            item_type ? "Dict[#{item_type}]" : "Dict"
+          when "array"
+            item_type ? "List[#{item_type}]" : "List"
+          else
+            type
+          end
+        end
+      end
+    end
+  end
+end

lib/completions/dialects/command.rb

@@ -24,8 +24,37 @@ module DiscourseAi
           system_message = messages.shift[:message] if messages.first[:role] == "SYSTEM"
 
           prompt = { preamble: +"#{system_message}" }
-          prompt[:chat_history] = messages if messages.present?
 
+          if messages.present?
+            with_mapped_tools = []
+
+            current_pair = nil
+            messages.each do |msg|
+              if current_pair == nil && msg[:type] == :tool_call
+                current_pair = [msg]
+              elsif current_pair && msg[:type] == :tool
+                current_pair << msg
+                tool_results = tools_dialect.tool_results(current_pair)
+                with_mapped_tools << { role: "TOOL", message: "", tool_results: tool_results }
+                current_pair = nil
+              else
+                with_mapped_tools << msg
+                current_pair = nil
+              end
+            end
+
+            messages = with_mapped_tools
+            prompt[:chat_history] = messages
+          end
+
+          tools = tools_dialect.translated_tools
+          prompt[:tools] = tools if tools.present?
+
+          tool_results =
+            messages.last && messages.last[:role] == "TOOL" && messages.last[:tool_results]
+          prompt[:tool_results] = tool_results if tool_results.present?
+
+          if tool_results.blank?
             messages.reverse_each do |msg|
               if msg[:role] == "USER"
                 prompt[:message] = msg[:message]
@@ -33,6 +62,7 @@ module DiscourseAi
                 break
               end
             end
+          end
 
           prompt
         end
@@ -54,8 +84,16 @@ module DiscourseAi
           end
         end
 
+        def native_tool_support?
+          true
+        end
+
         private
 
+        def tools_dialect
+          @tools_dialect ||= DiscourseAi::Completions::Dialects::CohereTools.new(prompt.tools)
+        end
+
         def per_message_overhead
           0
         end
@@ -83,11 +121,11 @@ module DiscourseAi
         end
 
         def tool_call_msg(msg)
-          { role: "CHATBOT", message: tools_dialect.from_raw_tool_call(msg) }
+          msg
         end
 
         def tool_msg(msg)
-          { role: "USER", message: tools_dialect.from_raw_tool(msg) }
+          msg
         end
 
         def user_msg(msg)

lib/completions/endpoints/cohere.rb

@@ -29,10 +29,7 @@ module DiscourseAi
         end
 
         def default_options(dialect)
-          options = { model: "command-r-plus" }
+          { model: "command-r-plus" }
-
-          options[:stop_sequences] = ["</function_calls>"] if dialect.prompt.has_tools?
-          options
         end
 
         def provider_id
@@ -49,7 +46,11 @@ module DiscourseAi
 
         def prepare_payload(prompt, model_params, dialect)
           payload = default_options(dialect).merge(model_params).merge(prompt)
-
+          if prompt[:tools].present?
+            payload[:tools] = prompt[:tools]
+            payload[:force_single_step] = false
+          end
+          payload[:tool_results] = prompt[:tool_results] if prompt[:tool_results].present?
           payload[:stream] = true if @streaming_mode
 
           payload
@@ -70,6 +71,14 @@ module DiscourseAi
           if @streaming_mode
             if parsed[:event_type] == "text-generation"
               parsed[:text]
+            elsif parsed[:event_type] == "tool-calls-generation"
+              # could just be random thinking...
+              if parsed.dig(:tool_calls).present?
+                @has_tool = true
+                parsed.dig(:tool_calls).to_json
+              else
+                ""
+              end
             else
               if parsed[:event_type] == "stream-end"
                 @input_tokens = parsed.dig(:response, :meta, :billed_units, :input_tokens)
@@ -84,6 +93,38 @@ module DiscourseAi
           end
         end
 
+        def has_tool?(_ignored)
+          @has_tool
+        end
+
+        def native_tool_support?
+          true
+        end
+
+        def add_to_function_buffer(function_buffer, partial: nil, payload: nil)
+          if partial
+            tools = JSON.parse(partial)
+            tools.each do |tool|
+              name = tool["name"]
+              parameters = tool["parameters"]
+              xml_params = parameters.map { |k, v| "<#{k}>#{v}</#{k}>\n" }.join
+
+              current_function = function_buffer.at("invoke")
+              if current_function.nil? || current_function.at("tool_name").content.present?
+                current_function =
+                  function_buffer.at("function_calls").add_child(
+                    Nokogiri::HTML5::DocumentFragment.parse(noop_function_call_text + "\n"),
+                  )
+              end
+
+              current_function.at("tool_name").content = name == "search_local" ? "search" : name
+              current_function.at("parameters").children =
+                Nokogiri::HTML5::DocumentFragment.parse(xml_params)
+            end
+          end
+          function_buffer
+        end
+
         def final_log_update(log)
           log.request_tokens = @input_tokens if @input_tokens
           log.response_tokens = @output_tokens if @output_tokens

spec/lib/completions/endpoints/cohere_spec.rb

@@ -59,6 +59,83 @@ RSpec.describe DiscourseAi::Completions::Endpoints::Cohere do
 
   before { SiteSetting.ai_cohere_api_key = "ABC" }
 
+  it "is able to trigger a tool" do
+    body = (<<~TEXT).strip
+      {"is_finished":false,"event_type":"stream-start","generation_id":"1648206e-1fe4-4bb6-90cf-360dd55f575b"}
+{"is_finished":false,"event_type":"tool-calls-generation","text":"I will search for 'who is sam saffron' and relay the information to the user.","tool_calls":[{"name":"google","parameters":{"query":"who is sam saffron"}}]}
+{"is_finished":true,"event_type":"stream-end","response":{"response_id":"71d8c9e1-1138-4d70-80d1-10ddec41c989","text":"I will search for 'who is sam saffron' and relay the information to the user.","generation_id":"1648206e-1fe4-4bb6-90cf-360dd55f575b","chat_history":[{"role":"USER","message":"sam: who is sam saffron?"},{"role":"CHATBOT","message":"I will search for 'who is sam saffron' and relay the information to the user.","tool_calls":[{"name":"google","parameters":{"query":"who is sam saffron"}}]}],"finish_reason":"COMPLETE","meta":{"api_version":{"version":"1"},"billed_units":{"input_tokens":460,"output_tokens":27},"tokens":{"input_tokens":1227,"output_tokens":27}},"tool_calls":[{"name":"google","parameters":{"query":"who is sam saffron"}}]},"finish_reason":"COMPLETE"}
+    TEXT
+
+    parsed_body = nil
+    result = +""
+
+    sig = {
+      name: "google",
+      description: "Will search using Google",
+      parameters: [
+        { name: "query", description: "The search query", type: "string", required: true },
+      ],
+    }
+
+    prompt.tools = [sig]
+
+    EndpointMock.with_chunk_array_support do
+      stub_request(:post, "https://api.cohere.ai/v1/chat").with(
+        body:
+          proc do |req_body|
+            parsed_body = JSON.parse(req_body, symbolize_names: true)
+            true
+          end,
+        headers: {
+          "Content-Type" => "application/json",
+          "Authorization" => "Bearer ABC",
+        },
+      ).to_return(status: 200, body: body.split("|"))
+
+      result = llm.generate(prompt, user: user) { |partial, cancel| result << partial }
+    end
+
+    expected = <<~TEXT
+      <function_calls>
+      <invoke>
+      <tool_name>google</tool_name>
+      <parameters><query>who is sam saffron</query>
+      </parameters>
+      <tool_id>tool_0</tool_id>
+      </invoke>
+      </function_calls>
+    TEXT
+
+    expect(result.strip).to eq(expected.strip)
+
+    expected = {
+      model: "command-r-plus",
+      preamble: "You are hello bot",
+      chat_history: [
+        { role: "USER", message: "user1: hello" },
+        { role: "CHATBOT", message: "hi user" },
+      ],
+      message: "user1: thanks",
+      tools: [
+        {
+          name: "google",
+          description: "Will search using Google",
+          parameter_definitions: {
+            query: {
+              description: "The search query",
+              type: "str",
+              required: true,
+            },
+          },
+        },
+      ],
+      force_single_step: false,
+      stream: true,
+    }
+
+    expect(parsed_body).to eq(expected)
+  end
+
   it "is able to run tools" do
     body = {
       response_id: "0a90275b-273d-4690-abce-8018edcec7d0",
@@ -99,20 +176,6 @@ RSpec.describe DiscourseAi::Completions::Endpoints::Cohere do
     result = llm.generate(prompt_with_tool_results, user: user)
 
     expect(parsed_body[:preamble]).to include("You are weather bot")
-    expect(parsed_body[:preamble]).to include("<tools>")
-
-    expected_message = <<~MESSAGE
-      <function_results>
-      <result>
-      <tool_name>weather</tool_name>
-      <json>
-      {"weather":"22c"}
-      </json>
-      </result>
-      </function_results>
-    MESSAGE
-
-    expect(parsed_body[:message].strip).to eq(expected_message.strip)
 
     expect(result).to eq("Sydney is 22c")
     audit = AiApiAuditLog.order("id desc").first