Add optional Claude system prompt cache.

default/config.yaml

@@ -41,6 +41,11 @@ enableCorsProxy: false
 enableUserAccounts: false
 # Enable discreet login mode: hides user list on the login screen
 enableDiscreetLogin: false
+# User session timeout *in seconds* (defaults to 24 hours).
+## Set to a positive number to expire session after a certain time of inactivity
+## Set to 0 to expire session when the browser is closed
+## Set to a negative number to disable session expiration
+sessionTimeout: 86400
 # Used to sign session cookies. Will be auto-generated if not set
 cookieSecret: ''
 # Disable CSRF protection - NOT RECOMMENDED
@@ -123,10 +128,14 @@ ollama:
   # * 0: Unload the model immediately after the request
   # * 5m: Keep the model loaded for 5 minutes after the request. Accepts duration strings (e.g. 5h30m40s)
   keepAlive: -1
+# -- ANTHROPIC CLAUDE API CONFIGURATION --
+claude:
+  # Enables caching of the system prompt (if supported).
+  # https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching
+  # -- IMPORTANT! --
+  # Use only when the prompt before the chat history is static and doesn't change between requests
+  # (e.g {{random}} macro or lorebooks not as in-chat injections).
+  # Otherwise, you'll just waste money on cache misses.
+  enableSystemPromptCache: false
 # -- SERVER PLUGIN CONFIGURATION --
 enableServerPlugins: false
-# User session timeout *in seconds* (defaults to 24 hours).
-## Set to a positive number to expire session after a certain time of inactivity
-## Set to 0 to expire session when the browser is closed
-## Set to a negative number to disable session expiration
-sessionTimeout: 86400

src/endpoints/backends/chat-completions.js

@@ -105,6 +105,7 @@ async function sendClaudeRequest(request, response) {
     const apiUrl = new URL(request.body.reverse_proxy || API_CLAUDE).toString();
     const apiKey = request.body.reverse_proxy ? request.body.proxy_password : readSecret(request.user.directories, SECRET_KEYS.CLAUDE);
     const divider = '-'.repeat(process.stdout.columns);
+    const enableSystemPromptCache = getConfigValue('claude.enableSystemPromptCache', false);
 
     if (!apiKey) {
         console.log(color.red(`Claude API key is missing.\n${divider}`));
@@ -118,8 +119,8 @@ async function sendClaudeRequest(request, response) {
             controller.abort();
         });
         const additionalHeaders = {};
-        let use_system_prompt = (request.body.model.startsWith('claude-2') || request.body.model.startsWith('claude-3')) && request.body.claude_use_sysprompt;
+        const useSystemPrompt = (request.body.model.startsWith('claude-2') || request.body.model.startsWith('claude-3')) && request.body.claude_use_sysprompt;
-        let converted_prompt = convertClaudeMessages(request.body.messages, request.body.assistant_prefill, use_system_prompt, request.body.human_sysprompt_message, request.body.char_name, request.body.user_name);
+        const convertedPrompt = convertClaudeMessages(request.body.messages, request.body.assistant_prefill, useSystemPrompt, request.body.human_sysprompt_message, request.body.char_name, request.body.user_name);
         // Add custom stop sequences
         const stopSequences = [];
         if (Array.isArray(request.body.stop)) {
@@ -127,7 +128,7 @@ async function sendClaudeRequest(request, response) {
         }
 
         const requestBody = {
-            messages: converted_prompt.messages,
+            messages: convertedPrompt.messages,
             model: request.body.model,
             max_tokens: request.body.max_tokens,
             stop_sequences: stopSequences,
@@ -136,13 +137,15 @@ async function sendClaudeRequest(request, response) {
             top_k: request.body.top_k,
             stream: request.body.stream,
         };
-        if (use_system_prompt) {
+        if (useSystemPrompt) {
-            requestBody.system = converted_prompt.systemPrompt;
+            requestBody.system = enableSystemPromptCache
+                ? [{ type: 'text', text: convertedPrompt.systemPrompt, cache_control: { type: 'ephemeral' } }]
+                : convertedPrompt.systemPrompt;
         }
         if (Array.isArray(request.body.tools) && request.body.tools.length > 0) {
             // Claude doesn't do prefills on function calls, and doesn't allow empty messages
-            if (converted_prompt.messages.length && converted_prompt.messages[converted_prompt.messages.length - 1].role === 'assistant') {
+            if (convertedPrompt.messages.length && convertedPrompt.messages[convertedPrompt.messages.length - 1].role === 'assistant') {
-                converted_prompt.messages.push({ role: 'user', content: '.' });
+                convertedPrompt.messages.push({ role: 'user', content: '.' });
             }
             additionalHeaders['anthropic-beta'] = 'tools-2024-05-16';
             requestBody.tool_choice = { type: request.body.tool_choice === 'required' ? 'any' : 'auto' };
@@ -151,6 +154,9 @@ async function sendClaudeRequest(request, response) {
                 .map(tool => tool.function)
                 .map(fn => ({ name: fn.name, description: fn.description, input_schema: fn.parameters }));
         }
+        if (enableSystemPromptCache) {
+            additionalHeaders['anthropic-beta'] = 'prompt-caching-2024-07-31';
+        }
         console.log('Claude request:', requestBody);
 
         const generateResponse = await fetch(apiUrl + '/messages', {