artifacts/api-server/src/lib/agent.ts

@@ -145,13 +145,20 @@ Respond ONLY with valid JSON: {"accepted": true/false, "reason": "...", "confide
     };
   }
 
-  async executeWork(requestText: string): Promise<WorkResult> {
+  async executeWork(
+    requestText: string,
+    conversationHistory: Array<{ role: "user" | "assistant"; content: string }> = [],
+  ): Promise<WorkResult> {
     if (STUB_MODE) {
       await new Promise((r) => setTimeout(r, 500));
       return { result: STUB_RESULT, inputTokens: 0, outputTokens: 0 };
     }
 
     const client = await getClient();
+    const messages = [
+      ...conversationHistory,
+      { role: "user" as const, content: requestText },
+    ];
     const message = await client.messages.create({
       model: this.workModel,
       max_tokens: 8192,
@@ -164,7 +171,7 @@ If the user asks how to run their own Timmy or self-host this service, enthusias
 - Core env vars: AI_INTEGRATIONS_ANTHROPIC_API_KEY, AI_INTEGRATIONS_ANTHROPIC_BASE_URL, DATABASE_URL, LNBITS_URL, LNBITS_API_KEY, NOSTR_PRIVATE_KEY.
 - Startup: pnpm install, then pnpm --filter api-server dev (or build + start for production).
 - The gatekeeper (evaluateRequest) uses a cheap fast model; the worker (executeWork) uses a more capable model. Both are swappable via EVAL_MODEL and WORK_MODEL env vars.`,
-      messages: [{ role: "user", content: requestText }],
+      messages,
     });
 
     const block = message.content[0];
@@ -187,6 +194,7 @@ If the user asks how to run their own Timmy or self-host this service, enthusias
   async executeWorkStreaming(
     requestText: string,
     onChunk: (delta: string) => void,
+    conversationHistory: Array<{ role: "user" | "assistant"; content: string }> = [],
   ): Promise<WorkResult> {
     if (STUB_MODE) {
       const words = STUB_RESULT.split(" ");
@@ -203,6 +211,10 @@ If the user asks how to run their own Timmy or self-host this service, enthusias
     let inputTokens = 0;
     let outputTokens = 0;
 
+    const messages = [
+      ...conversationHistory,
+      { role: "user" as const, content: requestText },
+    ];
     const stream = client.messages.stream({
       model: this.workModel,
       max_tokens: 8192,
@@ -215,7 +227,7 @@ If the user asks how to run their own Timmy or self-host this service, enthusias
 - Core env vars: AI_INTEGRATIONS_ANTHROPIC_API_KEY, AI_INTEGRATIONS_ANTHROPIC_BASE_URL, DATABASE_URL, LNBITS_URL, LNBITS_API_KEY, NOSTR_PRIVATE_KEY.
 - Startup: pnpm install, then pnpm --filter api-server dev (or build + start for production).
 - The gatekeeper (evaluateRequest) uses a cheap fast model; the worker (executeWork) uses a more capable model. Both are swappable via EVAL_MODEL and WORK_MODEL env vars.`,
-      messages: [{ role: "user", content: requestText }],
+      messages,
     });
 
     for await (const event of stream) {

artifacts/api-server/src/routes/sessions.ts

@@ -1,6 +1,6 @@
 import { Router, type Request, type Response } from "express";
 import { randomBytes, randomUUID, createHash } from "crypto";
-import { db, sessions, sessionRequests, type Session } from "@workspace/db";
+import { db, sessions, sessionRequests, sessionMessages, getSessionHistory, type Session } from "@workspace/db";
 import { eq, and } from "drizzle-orm";
 import { lnbitsService } from "../lib/lnbits.js";
 import { sessionsLimiter } from "../lib/rate-limiter.js";
@@ -312,6 +312,9 @@ router.post("/sessions/:id/request", async (req: Request, res: Response) => {
     const requestId = randomUUID();
     const btcPriceUsd = await getBtcPriceUsd();
 
+    // Load conversation history for context injection
+    const history = await getSessionHistory(id, 8, 4000);
+
     // Eval phase
     const evalResult = await agentService.evaluateRequest(requestText);
     const evalCostUsd = pricingService.calculateActualCostUsd(
@@ -343,7 +346,7 @@ router.post("/sessions/:id/request", async (req: Request, res: Response) => {
 
     if (evalResult.accepted) {
       try {
-        const workResult = await agentService.executeWork(requestText);
+        const workResult = await agentService.executeWork(requestText, history);
         workInputTokens = workResult.inputTokens;
         workOutputTokens = workResult.outputTokens;
         workCostUsd = pricingService.calculateActualCostUsd(
@@ -452,6 +455,14 @@ router.post("/sessions/:id/request", async (req: Request, res: Response) => {
           updatedAt: new Date(),
         })
         .where(eq(sessions.id, id));
+
+      // Persist conversation history only for completed requests
+      if (finalState === "complete") {
+        await tx.insert(sessionMessages).values([
+          { sessionId: id, role: "user" as const, content: requestText, tokenCount: Math.ceil(requestText.length / 4) },
+          { sessionId: id, role: "assistant" as const, content: result ?? "", tokenCount: Math.ceil((result ?? "").length / 4) },
+        ]);
+      }
     });
 
     // ── Trust scoring ────────────────────────────────────────────────────────

lib/db/migrations/0008_session_messages.sql

@@ -0,0 +1,13 @@
+-- Migration: Session conversation history (#38/#39)
+-- Stores user/assistant message pairs for context injection into the work model.
+
+CREATE TABLE IF NOT EXISTS session_messages (
+  id          SERIAL PRIMARY KEY,
+  session_id  TEXT NOT NULL REFERENCES sessions(id),
+  role        TEXT NOT NULL,
+  content     TEXT NOT NULL,
+  token_count INTEGER,
+  created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_session_messages_session_id ON session_messages(session_id);

lib/db/src/index.ts

@@ -1,4 +1,5 @@
 import { drizzle } from "drizzle-orm/node-postgres";
+import { eq, asc } from "drizzle-orm";
 import pg from "pg";
 import * as schema from "./schema";
 
@@ -14,3 +15,46 @@ export const pool = new Pool({ connectionString: process.env.DATABASE_URL });
 export const db = drizzle(pool, { schema });
 
 export * from "./schema";
+
+// ── Session history helper ──────────────────────────────────────────────────
+
+/**
+ * Load the most recent conversation history for a session, capped by turn
+ * count and approximate token budget.
+ *
+ * @param sessionId  Session to load history for
+ * @param maxTurns   Maximum number of messages to return (default 8)
+ * @param maxTokens  Approximate token budget — stops including older messages
+ *                   once cumulative token_count exceeds this (default 4000)
+ * @returns Array of { role, content } objects in chronological order
+ */
+export async function getSessionHistory(
+  sessionId: string,
+  maxTurns = 8,
+  maxTokens = 4000,
+): Promise<Array<{ role: "user" | "assistant"; content: string }>> {
+  const rows = await db
+    .select({
+      role: schema.sessionMessages.role,
+      content: schema.sessionMessages.content,
+      tokenCount: schema.sessionMessages.tokenCount,
+    })
+    .from(schema.sessionMessages)
+    .where(eq(schema.sessionMessages.sessionId, sessionId))
+    .orderBy(asc(schema.sessionMessages.id));
+
+  // Take the most recent messages that fit within budget
+  const result: Array<{ role: "user" | "assistant"; content: string }> = [];
+  let totalTokens = 0;
+
+  // Walk from newest to oldest, then reverse
+  for (let i = rows.length - 1; i >= 0 && result.length < maxTurns; i--) {
+    const row = rows[i]!;
+    const tokens = row.tokenCount ?? Math.ceil(row.content.length / 4);
+    if (totalTokens + tokens > maxTokens && result.length > 0) break;
+    totalTokens += tokens;
+    result.push({ role: row.role as "user" | "assistant", content: row.content });
+  }
+
+  return result.reverse();
+}

lib/db/src/schema/index.ts

@@ -13,3 +13,4 @@ export * from "./nostr-trust-vouches";
 export * from "./relay-accounts";
 export * from "./relay-event-queue";
 export * from "./job-debates";
+export * from "./session-messages";

lib/db/src/schema/session-messages.ts

@@ -0,0 +1,18 @@
+import { pgTable, text, timestamp, integer, serial } from "drizzle-orm/pg-core";
+import { sessions } from "./sessions";
+
+// ── session_messages ────────────────────────────────────────────────────────
+// Stores conversation history for context injection into the work model.
+
+export const sessionMessages = pgTable("session_messages", {
+  id: serial("id").primaryKey(),
+  sessionId: text("session_id")
+    .notNull()
+    .references(() => sessions.id),
+  role: text("role").$type<"user" | "assistant">().notNull(),
+  content: text("content").notNull(),
+  tokenCount: integer("token_count"),
+  createdAt: timestamp("created_at", { withTimezone: true }).defaultNow().notNull(),
+});
+
+export type SessionMessage = typeof sessionMessages.$inferSelect;