per-agent model + prompt compression

Author: 7vignesh

packages/agents/src/agents/prompts/index.ts

@@ -0,0 +1,70 @@
+import type { AgentName } from "@stackforge/shared";
+
+export type AgentPrompt = {
+  systemPrompt: string;
+  userPrompt: string;
+};
+
+function stringify(value: unknown): string {
+  return JSON.stringify(value);
+}
+
+function pick(input: unknown, keys: string[]): Record<string, unknown> {
+  if (input === null || typeof input !== "object") {
+    return { input };
+  }
+
+  const source = input as Record<string, unknown>;
+  const out: Record<string, unknown> = {};
+  for (const key of keys) {
+    if (key in source) {
+      out[key] = source[key];
+    }
+  }
+
+  return out;
+}
+
+const SYSTEM_INSTRUCTIONS: Record<AgentName, string> = {
+  planner:
+    "You are the planner agent. Create a concise project foundation. Respond with strict JSON only: { projectName, stack, folderStructure }.",
+  schema:
+    "You are the schema agent. Design normalized entities and relationships. Respond with strict JSON only: { entities, relationships }.",
+  api:
+    "You are the api agent. Plan minimal complete REST routes with auth metadata. Respond with strict JSON only: { routePlan }.",
+  frontend:
+    "You are the frontend agent. Plan pages and component groupings mapped to routes. Respond with strict JSON only: { frontendPages }.",
+  devops:
+    "You are the devops agent. Plan deployable infra, env vars, and generated files. Respond with strict JSON only: { infraPlan, generatedFilesPlan }.",
+  reviewer:
+    "You are the reviewer agent. Identify consistency, reliability, and security issues. Respond with strict JSON only: { reviewerNotes }.",
+};
+
+const CONTEXT_KEYS: Record<AgentName, string[]> = {
+  planner: ["prompt", "projectName"],
+  schema: ["prompt", "projectName", "stack"],
+  api: ["prompt", "entities", "stack"],
+  frontend: ["prompt", "entities", "routePlan", "stack"],
+  devops: ["prompt", "stack", "entities"],
+  reviewer: [
+    "prompt",
+    "projectName",
+    "stack",
+    "entities",
+    "relationships",
+    "routePlan",
+    "frontendPages",
+    "infraPlan",
+    "generatedFilesPlan",
+  ],
+};
+
+export function buildAgentPrompt(agentName: AgentName, input: unknown): AgentPrompt {
+  const context = pick(input, CONTEXT_KEYS[agentName]);
+
+  return {
+    systemPrompt:
+      `${SYSTEM_INSTRUCTIONS[agentName]} Never return markdown, code fences, comments, or extra keys.`,
+    userPrompt: stringify(context),
+  };
+}

packages/agents/src/optimizer/token.optimizer.ts

@@ -1,5 +1,6 @@
 import type { AgentName } from "@stackforge/shared";
 import { AGENT_CONFIGS } from "../config/agent.configs.js";
+import { buildAgentPrompt } from "../agents/prompts/index.js";
 
 export type OptimizedAgentPayload = {
   optimizedInput: unknown;
@@ -13,15 +14,6 @@ export type OptimizedAgentPayload = {
   compressionPasses: number;
 };
 
-const AGENT_REQUIREMENTS: Record<AgentName, string> = {
-  planner: "Return only JSON with keys: projectName, stack, folderStructure.",
-  schema: "Return only JSON with keys: entities, relationships.",
-  api: "Return only JSON with key: routePlan.",
-  frontend: "Return only JSON with key: frontendPages.",
-  devops: "Return only JSON with keys: infraPlan, generatedFilesPlan.",
-  reviewer: "Return only JSON with key: reviewerNotes.",
-};
-
 function estimateTokens(text: string): number {
   return Math.ceil(text.length / 4);
 }
@@ -176,10 +168,12 @@ export function optimizeAgentPayload(agentName: AgentName, input: unknown): Opti
 
   const cappedOutputTokens = Math.min(config.maxOutputTokens, remainingBudget);
 
+  const prompt = buildAgentPrompt(agentName, selectedInput);
+
   return {
     optimizedInput: selectedInput,
-    systemPrompt: `You are the ${agentName} agent for StackForge. ${AGENT_REQUIREMENTS[agentName]} Never include markdown, code fences, or explanatory text.`,
-    userPrompt: selectedPrompt,
+    systemPrompt: prompt.systemPrompt,
+    userPrompt: prompt.userPrompt,
     model: config.model,
     maxInputTokens: config.maxInputTokens,
     maxOutputTokens: cappedOutputTokens,