feat: optimize heartbeat token usage

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/adapters/opencode-local/src/server/execute.ts

@@ -9,6 +9,7 @@ import {
   asStringArray,
   parseObject,
   buildPaperclipEnv,
+  joinPromptSections,
   redactEnvForLogs,
   ensureAbsoluteDirectory,
   ensureCommandResolvable,
@@ -233,7 +234,8 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     ];
   })();
 
-  const renderedPrompt = renderTemplate(promptTemplate, {
+  const bootstrapPromptTemplate = asString(config.bootstrapPromptTemplate, "");
+  const templateData = {
     agentId: agent.id,
     companyId: agent.companyId,
     runId,
@@ -241,8 +243,26 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     agent,
     run: { id: runId, source: "on_demand" },
     context,
-  });
-  const prompt = `${instructionsPrefix}${renderedPrompt}`;
+  };
+  const renderedPrompt = renderTemplate(promptTemplate, templateData);
+  const renderedBootstrapPrompt =
+    !sessionId && bootstrapPromptTemplate.trim().length > 0
+      ? renderTemplate(bootstrapPromptTemplate, templateData).trim()
+      : "";
+  const sessionHandoffNote = asString(context.paperclipSessionHandoffMarkdown, "").trim();
+  const prompt = joinPromptSections([
+    instructionsPrefix,
+    renderedBootstrapPrompt,
+    sessionHandoffNote,
+    renderedPrompt,
+  ]);
+  const promptMetrics = {
+    promptChars: prompt.length,
+    instructionsChars: instructionsPrefix.length,
+    bootstrapPromptChars: renderedBootstrapPrompt.length,
+    sessionHandoffChars: sessionHandoffNote.length,
+    heartbeatPromptChars: renderedPrompt.length,
+  };
 
   const buildArgs = (resumeSessionId: string | null) => {
     const args = ["run", "--format", "json"];
@@ -264,6 +284,7 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
         commandArgs: [...args, `<stdin prompt ${prompt.length} chars>`],
         env: redactEnvForLogs(env),
         prompt,
+        promptMetrics,
         context,
       });
     }

packages/adapters/opencode-local/src/ui/build-config.ts

@@ -55,6 +55,7 @@ export function buildOpenCodeLocalConfig(v: CreateConfigValues): Record<string,
   if (v.cwd) ac.cwd = v.cwd;
   if (v.instructionsFilePath) ac.instructionsFilePath = v.instructionsFilePath;
   if (v.promptTemplate) ac.promptTemplate = v.promptTemplate;
+  if (v.bootstrapPrompt) ac.bootstrapPromptTemplate = v.bootstrapPrompt;
   if (v.model) ac.model = v.model;
   if (v.thinkingEffort) ac.variant = v.thinkingEffort;
   // OpenCode sessions can run until the CLI exits naturally; keep timeout disabled (0)