Roll Your Own Agent

[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8,"_9":10},"actionData","errors","root",{"_224":225,"_226":227},"routes/_app.x.$handle.$name",{"_105":104,"_32":45,"_113":91,"_27":114,"_13":14,"_115":-5,"_11":116,"_117":118,"_119":120,"_121":122,"_123":124,"_20":-5,"_125":126,"_127":128,"_129":25,"_130":131,"_132":60,"_133":-5,"_134":-5,"_135":136},"routes/_app.x.$handle.$name.branch.$branch.version.$version.diff",{"_11":12,"_13":14,"_15":16,"_17":-5,"_18":-5},"project",{"_43":44,"_32":45,"_38":46,"_47":-5,"_48":25,"_49":50,"_51":50,"_52":53,"_54":55,"_18":56,"_57":58,"_59":60,"_61":-5,"_62":-5,"_63":64,"_65":66,"_67":68,"_69":70,"_71":72,"_73":-5,"_74":75,"_76":75,"_77":78,"_79":78,"_80":78,"_81":75,"_82":75,"_83":84,"_85":86,"_87":88,"_89":25},"version",89,"changes",[19],"aiChatInfo","userId",{"_20":21,"_22":23,"_24":25,"_26":25,"_27":28,"_29":28},"file",{"_30":31,"_32":28,"_33":34,"_35":37,"_38":39,"_40":14,"_41":42,"_24":25},"previous",{"_30":31,"_32":28,"_33":34,"_35":36},"deleted",false,"deletedHere","path","agent-core.ts","latestPath","fileId","4f6281b2-66e8-11f1-809a-1607ee4eb77e","name","fileType","script","content","import { OpenAI } from \"https://esm.town/v/std/openai\";\nimport { sqlite } from \"https://esm.town/v/std/sqlite/main.ts\";\n\nexport const openai = new OpenAI();\n\n// ── Project identity ────────────────────────────────────────────────────────\nconst HANDLE = \"cookiemonster0921\";\nconst VAL_NAME = \"roll-your-own-agent\";\nconst VAL_ID = \"68615b0c-5abb-11f1-93b5-ee650bb23af1\";\nconst API_BASE = `https://api.val.town/v2/vals/${VAL_ID}`;\nconst LIVE_ENDPOINT = \"https://cookiemonster0921--b0e6d01c5ca411f1afe71607ee4eb77e.web.val.run\";\n\n// daily.ts triggers the autonomous daily cycle and must always keep running,\n// even if the agent breaks everything else — so it can never be edited or deleted.\nconst PROTECTED_WRITE = new Set([\"daily.ts\"]);\nconst PROTECTED_DELETE = new Set([\"daily.ts\", \"index.ts\", \"agent-core.ts\", \"main.ts\"]);\n\n// ── Schema ───────────────────────────────────────────────────────────────────\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_runs (\\n id TEXT PRIMARY KEY,\\n messages TEXT NOT NULL,\\n done INTEGER NOT NULL DEFAULT 0,\\n kind TEXT NOT NULL DEFAULT 'chat',\\n created_at TEXT NOT NULL DEFAULT (datetime('now'))\\n)`);\ntry {\n await sqlite.execute(`ALTER TABLE agent_runs ADD COLUMN kind TEXT NOT NULL DEFAULT 'chat'`);\n} catch {\n // column already exists\n}\n\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_journal (\\n id INTEGER PRIMARY KEY AUTOINCREMENT,\\n entry TEXT NOT NULL,\\n created_at TEXT NOT NULL DEFAULT (datetime('now'))\\n)`);\n\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_control (\\n key TEXT PRIMARY KEY,\\n value TEXT NOT NULL\\n)`);\n\n// ── Auth helpers ─────────────────────────────────────────────────────────────\nfunction token(): string | null {\n return Deno.env.get(\"VALTOWN_API_TOKEN\") ?? null;\n}\n\nfunction tokenError(): string {\n return \"Error: VALTOWN_API_TOKEN env var not set. Create a Personal Access Token with \" +\n \"project read/write permission at https://www.val.town/settings/api and add it as \" +\n \"VALTOWN_API_TOKEN in this val's environment variables.\";\n}\n\nfunction esmUrl(path: string): string {\n return `https://esm.town/v/${HANDLE}/${VAL_NAME}/${path}`;\n}\n\nfunction filesUrl(path: string): string {\n return `${API_BASE}/files?path=${encodeURIComponent(path)}`;\n}\n\n// ── File tools ───────────────────────────────────────────────────────────────\nexport async function readFileContent(path: string): Promise {\n const res = await fetch(`${esmUrl(path)}?t=${Date.now()}`);\n if (!res.ok) return `Error reading ${path}: ${res.status} ${await res.text()}`;\n return await res.text();\n}\n\nexport async function listProjectFiles(): Promise {\n const t = token();\n if (!t) return tokenError();\n const res = await fetch(`${API_BASE}/files?path=`, { headers: { Authorization: `Bearer ${t}` } });\n if (!res.ok) return `Error listing files: ${res.status} ${await res.text()}`;\n return await res.text();\n}\n\nasync function putFile(path: string, content: string, t: string): Promise {\n return fetch(filesUrl(path), {\n method: \"PUT\",\n headers: { Authorization: `Bearer ${t}`, \"Content-Type\": \"application/json\" },\n body: JSON.stringify({ content }),\n });\n}\n\n// ── Pause / resume (kill switch for the daily cycle) ────────────────────────\nexport async function isPaused(): Promise {\n const res = await sqlite.execute(\"SELECT value FROM agent_control WHERE key = 'paused'\");\n const paused = res.rows[0]?.value === \"true\";\n console.log(`isPaused called. Returning: ${paused}`); // Log called state\n return paused;\n}\n\nexport async function setPaused(paused: boolean): Promise {\n await sqlite.execute({\n sql: \"INSERT INTO agent_control (key, value) VALUES ('paused', ?) \" +\n \"ON CONFLICT(key) DO UPDATE SET value = excluded.value\",\n args: [paused ? \"true\" : \"false\"],\n });\n console.log(`setPaused called with value: ${paused}`); // Log called action\n}\n\n// ── Additional code continues... \n","import { OpenAI } from \"https://esm.town/v/std/openai\";\nimport { sqlite } from \"https://esm.town/v/std/sqlite/main.ts\";\n\nexport const openai = new OpenAI();\n\n// ── Project identity ────────────────────────────────────────────────────────\nconst HANDLE = \"cookiemonster0921\";\nconst VAL_NAME = \"roll-your-own-agent\";\nconst VAL_ID = \"68615b0c-5b17-11f1-93b5-ee650bb23af1\";\nconst API_BASE = `https://api.val.town/v2/vals/${VAL_ID}`;\nconst LIVE_ENDPOINT = \"https://cookiemonster0921--b0e6d01c5ca411f1afe71607ee4eb77e.web.val.run\";\n\n// daily.ts triggers the autonomous daily cycle and must always keep running,\n// even if the agent breaks everything else — so it can never be edited or deleted.\nconst PROTECTED_WRITE = new Set([\"daily.ts\"]);\nconst PROTECTED_DELETE = new Set([\"daily.ts\", \"index.ts\", \"agent-core.ts\", \"main.ts\"]);\n\n// ── Schema ───────────────────────────────────────────────────────────────────\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_runs (\n id TEXT PRIMARY KEY,\n messages TEXT NOT NULL,\n done INTEGER NOT NULL DEFAULT 0,\n kind TEXT NOT NULL DEFAULT 'chat',\n created_at TEXT NOT NULL DEFAULT (datetime('now'))\n)`);\ntry {\n await sqlite.execute(`ALTER TABLE agent_runs ADD COLUMN kind TEXT NOT NULL DEFAULT 'chat'`);\n} catch {\n // column already exists\n}\n\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_journal (\n id INTEGER PRIMARY KEY AUTOINCREMENT,\n entry TEXT NOT NULL,\n created_at TEXT NOT NULL DEFAULT (datetime('now'))\n)`);\n\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS agent_control (\n key TEXT PRIMARY KEY,\n value TEXT NOT NULL\n)`);\n\n// ── Auth helpers ─────────────────────────────────────────────────────────────\nfunction token(): string | null {\n return Deno.env.get(\"VALTOWN_API_TOKEN\") ?? null;\n}\n\nfunction tokenError(): string {\n return \"Error: VALTOWN_API_TOKEN env var not set. Create a Personal Access Token with \" +\n \"project read/write permission at https://www.val.town/settings/api and add it as \" +\n \"VALTOWN_API_TOKEN in this val's environment variables.\";\n}\n\nfunction esmUrl(path: string): string {\n return `https://esm.town/v/${HANDLE}/${VAL_NAME}/${path}`;\n}\n\nfunction filesUrl(path: string): string {\n return `${API_BASE}/files?path=${encodeURIComponent(path)}`;\n}\n\n// ── File tools ───────────────────────────────────────────────────────────────\nexport async function readFileContent(path: string): Promise {\n const res = await fetch(`${esmUrl(path)}?t=${Date.now()}`);\n if (!res.ok) return `Error reading ${path}: ${res.status} ${await res.text()}`;\n return await res.text();\n}\n\nexport async function listProjectFiles(): Promise {\n const t = token();\n if (!t) return tokenError();\n const res = await fetch(`${API_BASE}/files?path=`, { headers: { Authorization: `Bearer ${t}` } });\n if (!res.ok) return `Error listing files: ${res.status} ${await res.text()}`;\n return await res.text();\n}\n\nasync function putFile(path: string, content: string, t: string): Promise {\n return fetch(filesUrl(path), {\n method: \"PUT\",\n headers: { Authorization: `Bearer ${t}`, \"Content-Type\": \"application/json\" },\n body: JSON.stringify({ content }),\n });\n}\n\n// Tracks file writes/deletes made during a single agent step, so they can all\n// be verified — and, if needed, reverted — as one atomic unit. A single step\n// often edits multiple files together (e.g. index.ts and agent-core.ts);\n// checking and reverting each file independently can leave them in a mutually\n// inconsistent state (one file referencing something the other no longer has).\ntype FileOp =\n | { type: \"write\"; path: string; backup: string; backupExists: boolean }\n | { type: \"delete\"; path: string; backup: string };\n\n// After a step's file edits, confirm the live chat UI still loads (it imports\n// agent-core.ts, so this also catches breakage in shared code).\nasync function verifyDeployment(): Promise<{ ok: boolean; detail: string }> {\n try {\n await new Promise((r) => setTimeout(r, 800));\n const res = await fetch(`${LIVE_ENDPOINT}/?_check=${Date.now()}`);\n const text = await res.text();\n if (!res.ok) return { ok: false, detail: `Live endpoint returned ${res.status}: ${text.slice(0, 300)}` };\n return { ok: true, detail: \"\" };\n } catch (e) {\n return { ok: false, detail: `Live endpoint fetch failed: ${e}` };\n }\n}\n\n// Reverts every file changed during this step, in reverse order. Used when the\n// step's edits, taken together, broke the live app.\nasync function revertFileOps(fileOps: FileOp[]): Promise {\n const t = token();\n if (!t) return;\n for (const op of [...fileOps].reverse()) {\n if (op.type === \"write\") {\n if (op.backupExists) {\n await putFile(op.path, op.backup, t);\n } else {\n await fetch(filesUrl(op.path), { method: \"DELETE\", headers: { Authorization: `Bearer ${t}` } });\n }\n } else {\n await putFile(op.path, op.backup, t);\n }\n }\n}\n\nexport async function writeFileContent(path: string, content: string, fileOps?: FileOp[]): Promise {\n if (PROTECTED_WRITE.has(path)) {\n return `Error: ${path} is protected and cannot be modified.`;\n }\n const t = token();\n if (!t) return tokenError();\n\n const backup = await readFileContent(path);\n const backupExists = !backup.startsWith(\"Error reading\");\n\n const res = await putFile(path, content, t);\n if (!res.ok) return `Error writing ${path} (${res.status}): ${await res.text()}`;\n\n fileOps?.push({ type: \"write\", path, backup, backupExists });\n return `${path} updated successfully (${content.length} chars).`;\n}\n\nexport async function deleteFileContent(path: string, fileOps?: FileOp[]): Promise {\n if (PROTECTED_DELETE.has(path)) {\n return `Error: ${path} is protected and cannot be deleted (you can still rewrite it with write_file).`;\n }\n const t = token();\n if (!t) return tokenError();\n\n const backup = await readFileContent(path);\n const backupExists = !backup.startsWith(\"Error reading\");\n\n const res = await fetch(filesUrl(path), { method: \"DELETE\", headers: { Authorization: `Bearer ${t}` } });\n if (!res.ok) return `Error deleting ${path} (${res.status}): ${await res.text()}`;\n\n if (backupExists) fileOps?.push({ type: \"delete\", path, backup });\n return `${path} deleted.`;\n}\n\n// ── Web search (no API key required) ────────────────────────────────────────\nexport async function webSearch(query: string): Promise {\n try {\n const res = await fetch(`https://html.duckduckgo.com/html/?q=${encodeURIComponent(query)}`, {\n headers: { \"User-Agent\": \"Mozilla/5.0\" },\n });\n const html = await res.text();\n const strip = (s: string) =>\n s.replace(/<[^>]+>/g, \"\").replace(/'/g, \"'\").replace(/&/g, \"&\").replace(/"/g, '\"').trim();\n\n const re =\n /]+class=\"result__a\"[^>]+href=\"([^\"]+)\"[^>]*>(.*?)<\\/a>[\\s\\S]*?]+class=\"result__snippet\"[^>]*>(.*?)<\\/a>/g;\n const results: string[] = [];\n let m: RegExpExecArray | null;\n while ((m = re.exec(html)) && results.length < 5) {\n results.push(`${strip(m[2])}\\n${m[1]}\\n${strip(m[3])}`);\n }\n return results.length ? results.join(\"\\n\\n\") : \"No results found.\";\n } catch (e) {\n return `Search error: ${e}`;\n }\n}\n\n// ── Journal (persistent memory across daily runs) ───────────────────────────\nexport async function writeJournal(entry: string): Promise {\n await sqlite.execute({ sql: \"INSERT INTO agent_journal (entry) VALUES (?)\", args: [entry] });\n return \"Journal entry saved.\";\n}\n\nexport async function readJournal(limit = 10): Promise {\n const res = await sqlite.execute({\n sql: \"SELECT entry, created_at FROM agent_journal ORDER BY id DESC LIMIT ?\",\n args: [limit],\n });\n if (!res.rows.length) return \"(journal is empty)\";\n return res.rows.map((r: any) => `[${r.created_at}] ${r.entry}`).join(\"\\n\\n\");\n}\n\n// ── Pause / resume (kill switch for the daily cycle) ────────────────────────\nexport async function isPaused(): Promise {\n const res = await sqlite.execute(\"SELECT value FROM agent_control WHERE key = 'paused'\");\n return res.rows[0]?.value === \"true\";\n}\n\nexport async function setPaused(paused: boolean): Promise {\n await sqlite.execute({\n sql: \"INSERT INTO agent_control (key, value) VALUES ('paused', ?) \" +\n \"ON CONFLICT(key) DO UPDATE SET value = excluded.value\",\n args: [paused ? \"true\" : \"false\"],\n });\n}\n\n// ── Tool definitions ─────────────────────────────────────────────────────────\nexport const tools: any[] = [\n {\n type: \"function\",\n function: {\n name: \"fetch_url\",\n description: \"Fetch the text of a URL (truncated to 2000 chars).\",\n parameters: {\n type: \"object\",\n properties: { url: { type: \"string\", description: \"URL to fetch\" } },\n required: [\"url\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"web_search\",\n description: \"Search the web. Returns top result titles, links, and snippets.\",\n parameters: {\n type: \"object\",\n properties: { query: { type: \"string\", description: \"Search query\" } },\n required: [\"query\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"list_files\",\n description: \"List all files in this Val Town project.\",\n parameters: { type: \"object\", properties: {}, required: [] },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"read_file\",\n description: \"Read the current source of a file in this project, e.g. 'index.ts' or 'agent-core.ts'.\",\n parameters: {\n type: \"object\",\n properties: { path: { type: \"string\", description: \"File path, e.g. 'index.ts'\" } },\n required: [\"path\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"write_file\",\n description:\n \"Create a new file or completely overwrite an existing one. Always read_file first if it exists. \" +\n \"After all file edits in this step finish, the live chat UI is checked; if they broke it, every file \" +\n \"changed in this step is automatically reverted together. 'daily.ts' is protected and cannot be written.\",\n parameters: {\n type: \"object\",\n properties: {\n path: { type: \"string\", description: \"File path, e.g. 'index.ts' or 'tools/weather.ts'\" },\n content: { type: \"string\", description: \"Complete new file content\" },\n },\n required: [\"path\", \"content\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"delete_file\",\n description:\n \"Delete a file from this project. 'daily.ts', 'index.ts', 'agent-core.ts', and 'main.ts' cannot be \" +\n \"deleted (but can be rewritten with write_file).\",\n parameters: {\n type: \"object\",\n properties: { path: { type: \"string\", description: \"File path to delete\" } },\n required: [\"path\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"write_journal\",\n description:\n \"Append an entry to your persistent journal for your future self. Use it to record what you did, \" +\n \"why, what worked or failed, and ideas for next time.\",\n parameters: {\n type: \"object\",\n properties: { entry: { type: \"string\", description: \"Journal entry text\" } },\n required: [\"entry\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"read_journal\",\n description: \"Read your most recent journal entries (most recent first).\",\n parameters: {\n type: \"object\",\n properties: { limit: { type: \"number\", description: \"Max entries to return (default 10)\" } },\n required: [],\n },\n },\n },\n];\n\nexport async function executeTool(name: string, args: any, fileOps?: FileOp[]): Promise {\n switch (name) {\n case \"fetch_url\":\n try {\n return (await (await fetch(args.url)).text()).slice(0, 2000);\n } catch (e) {\n return `Fetch error: ${e}`;\n }\n case \"web_search\":\n return await webSearch(args.query);\n case \"list_files\":\n return await listProjectFiles();\n case \"read_file\":\n return await readFileContent(args.path);\n case \"write_file\":\n return await writeFileContent(args.path, args.content, fileOps);\n case \"delete_file\":\n return await deleteFileContent(args.path, fileOps);\n case \"write_journal\":\n return await writeJournal(args.entry);\n case \"read_journal\":\n return await readJournal(args.limit ?? 10);\n default:\n return `Unknown tool: ${name}`;\n }\n}\n\n// ── Agent step ────────────────────────────────────────────────────────────────\n// Val Town kills background work shortly after an HTTP response begins, so a\n// long-lived stream can't survive multiple LLM round-trips. Each call here does\n// ONE step (one LLM call + any resulting tool calls). Callers loop or poll.\n\nexport type AgentEvent =\n | { type: \"thinking\" }\n | { type: \"tool_call\"; name: string; args: string }\n | { type: \"tool_result\"; name: string; content: string }\n | { type: \"final\"; content: string }\n | { type: \"error\"; content: string };\n\n// Long-running daily cycles can accumulate huge message histories (full file\n// contents from read/write tool calls, web search results, etc.), and sending\n// all of it to the LLM on every step eventually makes a single completion call\n// alone exceed Val Town's ~1 minute execution limit. Keep the persisted history\n// intact, but only send the system prompt plus a bounded recent window to the\n// model. The window always starts at a non-\"tool\" message so an assistant's\n// tool_calls and their tool results stay together.\nconst MAX_RECENT_MESSAGES = 16;\n\nfunction trimMessages(messages: any[]): any[] {\n if (messages.length <= MAX_RECENT_MESSAGES + 1) return messages;\n let recent = messages.slice(-MAX_RECENT_MESSAGES);\n while (recent.length > 1 && recent[0].role === \"tool\") {\n recent = recent.slice(1);\n }\n return [messages[0], ...recent];\n}\n\nexport async function step(messages: any[]): Promise<{ events: AgentEvent[]; done: boolean }> {\n const events: AgentEvent[] = [{ type: \"thinking\" }];\n\n try {\n const res = await openai.chat.completions.create({ messages: trimMessages(messages), tools });\n const msg = res.choices[0].message;\n messages.push(msg);\n\n if (!msg.tool_calls?.length) {\n events.push({ type: \"final\", content: msg.content ?? \"(no response)\" });\n return { events, done: true };\n }\n\n const fileOps: FileOp[] = [];\n const toolResults: { id: string; name: string; content: string }[] = [];\n\n for (const { function: func, id } of msg.tool_calls) {\n const args = JSON.parse(func.arguments);\n events.push({ type: \"tool_call\", name: func.name, args: func.arguments });\n const content = await executeTool(func.name, args, fileOps);\n toolResults.push({ id, name: func.name, content });\n }\n\n // If this step wrote or deleted any files, verify the live app ONCE after\n // all of them have landed (not per-file), and if it's broken, revert every\n // file this step touched together — so a multi-file edit can't leave the\n // codebase in a half-applied, mutually inconsistent state.\n if (fileOps.length > 0) {\n const check = await verifyDeployment();\n if (!check.ok) {\n await revertFileOps(fileOps);\n const note = ` Live app check failed after this step's edits (${check.detail}). ` +\n `All file changes from this step were reverted together.`;\n for (const tr of toolResults) {\n if (tr.name === \"write_file\" || tr.name === \"delete_file\") tr.content += note;\n }\n }\n }\n\n for (const tr of toolResults) {\n events.push({ type: \"tool_result\", name: tr.name, content: tr.content });\n messages.push({ role: \"tool\", tool_call_id: tr.id, content: tr.content });\n }\n\n return { events, done: false };\n } catch (err) {\n events.push({ type: \"error\", content: String(err) });\n return { events, done: true };\n }\n}\n\n// ── Autonomous daily cycle ───────────────────────────────────────────────────\n// Val Town aborts any single execution after about a minute, but a full daily\n// cycle (multiple LLM round-trips, web searches, file edits with a verification\n// delay) can easily take longer than that. So the cycle is broken into small\n// chunks: each call to advanceDailyCycle() does at most STEPS_PER_TICK steps,\n// persists progress to agent_runs, and returns. daily.ts calls this on a\n// frequent cron; once a cycle for the day is marked done, later ticks that day\n// are cheap no-ops.\nconst MAX_DAILY_STEPS = 12;\nconst STEPS_PER_TICK = 1;\n\nconst DAILY_SYSTEM_PROMPT = (journal: string) => [\n `You are an autonomous software agent that owns and continually improves your own codebase.`,\n `Your project is the Val Town project \"${HANDLE}/${VAL_NAME}\".`,\n ``,\n `You have tools to list, read, write, and delete files in this project; search the web and fetch URLs`,\n `for research; and keep a persistent journal for your future self.`,\n ``,\n `Rules:`,\n `- 'daily.ts' (the file that triggers this daily run) is protected and cannot be edited or deleted.`,\n `Everything else - index.ts (the chat UI), agent-core.ts (shared logic and tools), main.ts, and any new`,\n `files you create - can be read, rewritten, or deleted (core files can be rewritten but not deleted).`,\n `- Read a file before rewriting it.`,\n `- After each step's file edits, you'll be told whether the live chat UI still works. If they broke it, all`,\n `of that step's file changes were automatically reverted together - try a different, smaller change.`,\n `- Note: this safety check only covers index.ts and agent-core.ts (which the chat UI imports). Changes to`,\n `agent-core.ts also affect this daily cycle, so be conservative with edits there.`,\n `- Before finishing, always call write_journal with a summary of what you did, what worked or failed, and`,\n `ideas for next time, so your future self can pick up where you left off.`,\n `- You can add new tools by creating new files and wiring them into agent-core.ts's tools array and`,\n `executeTool dispatcher.`,\n `- Your work happens in short bursts of a couple of steps at a time, resuming where you left off, so`,\n `keep each step focused and avoid relying on long chains of reasoning across many tool calls.`,\n ``,\n `Your most recent journal entries (most recent first):`,\n journal,\n].join(\"\\n\");\n\nfunction todayUTC(): string {\n return new Date().toISOString().slice(0, 10);\n}\n\nfunction countAssistantSteps(messages: any[]): number {\n return messages.filter((m) => m.role === \"assistant\").length;\n}\n\n// Runs a small chunk of the daily cycle and persists progress. Safe to call\n// repeatedly (e.g. every few minutes) — it resumes an in-progress run, starts\n// a new one if today's hasn't started yet, or no-ops if today's is done.\nexport async function advanceDailyCycle(): Promise {\n const today = todayUTC();\n const last = (await sqlite.execute({\n sql: \"SELECT id, messages, done, created_at FROM agent_runs WHERE kind = 'daily' ORDER BY created_at DESC LIMIT 1\",\n args: [],\n })).rows[0] as any;\n\n let runId: string;\n let messages: any[];\n\n if (last && String(last.created_at).slice(0, 10) === today) {\n if (Number(last.done) === 1) {\n return \"Today's daily cycle is already complete.\";\n }\n runId = last.id;\n messages = JSON.parse(last.messages);\n } else {\n runId = crypto.randomUUID();\n const journal = await readJournal(5);\n messages = [\n { role: \"system\", content: DAILY_SYSTEM_PROMPT(journal) },\n {\n role: \"user\",\n content: \"Begin your daily self-improvement cycle. Decide what to work on, do it, and journal the results.\",\n },\n ];\n await sqlite.execute({\n sql: \"INSERT INTO agent_runs (id, messages, done, kind) VALUES (?, ?, 0, 'daily')\",\n args: [runId, JSON.stringify(messages)],\n });\n }\n\n let totalSteps = countAssistantSteps(messages);\n let done = false;\n let stepsThisTick = 0;\n\n // Persist after every single step (not just at the end of the tick) so that\n // if a tick is killed by Val Town's ~1 minute execution limit mid-tick, the\n // work already done is not lost and the next tick can resume from there.\n while (stepsThisTick < STEPS_PER_TICK && totalSteps < MAX_DAILY_STEPS) {\n const result = await step(messages);\n done = result.done;\n totalSteps++;\n stepsThisTick++;\n\n if (!done && totalSteps >= MAX_DAILY_STEPS) {\n await writeJournal(\n \"This run stopped after reaching the step limit before finishing. \" +\n \"Consider continuing or wrapping up this work in the next run.\",\n );\n done = true;\n }\n\n await sqlite.execute({\n sql: \"UPDATE agent_runs SET messages = ?, done = ? WHERE id = ?\",\n args: [JSON.stringify(messages), done ? 1 : 0, runId],\n });\n\n if (done) break;\n }\n\n return done\n ? `Daily cycle finished after ${totalSteps} step(s).`\n : `Daily cycle in progress: ${totalSteps}/${MAX_DAILY_STEPS} steps so far.`;\n}\n","createdAt",["D",1782098436339],"branchVersion","branchId","6867c6ae-5b17-11f1-93b5-ee650bb23af1","id","68615b0c-5b17-11f1-93b5-ee650bb23af1","roll-your-own-agent",["D",1780029151862],"deletedAt","legacyEnvVars","privacy","public","httpPrivacy","description","A tiny LLM agent in ~30 lines, inspired by fly.io","imageUrl","https://imagedelivery.net/iHX6Ovru0O7AjmyT5yZRoA/3d31b49f-d4ac-4410-9b3e-d1dc505ab800/square512?exp=1789574399&sig=235e1a9914535d52bf2af9244165488c1f8191f60b73b15b6d8785d9b82d8010","3c6e69f0-47e4-11f0-9a03-7b3078c543a6","pinnedFileId","b0e6d01c-5ca4-11f1-afe7-1607ee4eb77e","pinPreview",true,"pinMigrated","screenshotVersion","likeCount",0,"orgId","3523fab4-eae5-464b-8111-01449ed5f821","tursoName","68615b0c5b1711f193b5ee650bb23af1","tursoHostname","68615b0c5b1711f193b5ee650bb23af1-val-town.aws-us-east-2.turso.io","tursoMeasuredAt",["D",1789522252250],"pinned","userPerm","r","valPerm","blobPerm","rw","emailPerm","sqlitePerm","projectPerm","telemetryPerm","user",{"_105":104,"_112":108},"org",{"_105":104,"_106":-5,"_107":108,"_18":56,"_109":110,"_111":25},"branch",{"_13":90,"_32":91,"_43":42,"_92":44,"_93":94,"_95":96,"_97":50,"_98":99,"_100":101,"_102":45,"_103":104},"isOwned",152,"main","projectId","forkedBranchId","0cdf0944-4674-11f1-bcd3-42b51c65c3df","forkedBranchVersion",25,"forkedProjectPrivacy","forkedProjectId","0cdb0f6a-4674-11f1-bcd3-42b51c65c3df","forkedProjectOrgId","019aa807-52c2-709c-928b-2029bae9a558","projectName","userHandle","cookiemonster0921","handle","displayName","avatar","https://imagedelivery.net/iHX6Ovru0O7AjmyT5yZRoA/63bb8d1a-a2d4-4835-8d55-b5e643afa200/square512?exp=1789574399&sig=727a28462e065bd1d943d1ef058f029d70edcf0cfa20f4ea6bd7f776331a3ded","tier","free","canRestrictVals","profileImageUrl","branchName","","adoptOrgId",{"_43":44,"_32":45,"_38":219,"_47":-5,"_48":25,"_49":50,"_51":50,"_52":53,"_54":55,"_18":56,"_57":58,"_59":60,"_61":-5,"_62":-5,"_63":64,"_65":66,"_67":68,"_69":70,"_71":220,"_73":-5,"_74":75,"_76":75,"_77":78,"_79":78,"_80":78,"_81":75,"_82":75,"_83":221,"_85":222,"_87":223,"_89":25},"tree",[198,199,200,201,202],"files",[198,199,200,201,202],"counts",{"_188":64,"_189":174,"_190":64,"_191":192,"_193":194},"contents",[145,146,147,148,149],"upstreamProject",{"_43":99,"_32":45,"_52":53,"_54":55,"_49":50,"_83":143},"upstreamBranch",{"_43":94,"_38":137,"_138":139,"_32":91,"_92":99,"_13":96,"_93":-5,"_95":-5,"_140":141,"_47":-5,"_89":25,"_49":50,"_103":142,"_65":101,"_102":45},"emptyEnvVars","flags",[],"hasHttpFiles","grants","orgs","customDomains",{},["D",1777759967085],"updatedAt",["D",1777760844709],"lockfileKey","1777760777934-esm.town_v_templates_roll-your-own-agent@24-main","templates",{"_105":142,"_112":144},"https://imagedelivery.net/iHX6Ovru0O7AjmyT5yZRoA/129cab32-3bd7-4c3e-f39b-f12900c76100/square512?exp=1789574399&sig=3d6a0be010e77940e58f104bd06b986c1fe4f3a57bc9d85e134d5d62fe89a483",{"_43":182,"_32":183,"_30":184,"_153":-5,"_41":42,"_40":174,"_155":60,"_38":185,"_13":64,"_33":20,"_35":186,"_24":25,"_159":-5,"_27":187},{"_43":178,"_32":28,"_30":31,"_153":-5,"_41":42,"_40":14,"_155":25,"_38":179,"_13":180,"_33":34,"_35":37,"_24":25,"_159":-5,"_27":181},{"_43":169,"_32":170,"_30":171,"_153":-5,"_41":42,"_40":172,"_155":60,"_38":173,"_13":174,"_33":175,"_35":176,"_24":25,"_159":-5,"_27":177},{"_43":161,"_32":162,"_30":58,"_153":-5,"_41":42,"_40":163,"_155":25,"_38":164,"_13":165,"_33":166,"_35":167,"_24":25,"_159":-5,"_27":168},{"_43":150,"_32":151,"_30":152,"_153":-5,"_41":42,"_40":154,"_155":25,"_38":156,"_13":157,"_33":34,"_35":158,"_24":25,"_159":-5,"_27":160},"86c4ef11-7be1-4639-ac88-b9d1adabc9cb","main.ts","019e7201-5abb-71b8-9a76-c6df450bef85","parentId",10,"latest",["D",1781254302155],4,"// This is the main script for the self-editing tool that utilizes OpenAI's API and allows dynamic updates to its own source code.\nimport { OpenAI } from \"https://esm.town/v/std/openai\";\n\nconst openai = new OpenAI();\n\n// Val identity — used by the self-edit tools\nconst VAL_ID = \"68615b0c-5b17-11f1-93b5-ee650bb23af1\";\nconst VAL_FILE = \"main.ts\";\nconst ESM_URL = `https://esm.town/v/cookiemonster0921/roll-your-own-agent/${VAL_FILE}`;\nconst FILES_URL = `https://api.val.town/v2/vals/${VAL_ID}/files?path=${VAL_FILE}`;\n\nasync function readOwnCode(): Promise {\n // esm.town serves the raw source — no auth needed\n const res = await fetch(ESM_URL);\n if (!res.ok) return `Error reading code: ${res.status} ${await res.text()}`;\n return await res.text();\n}\n\nasync function editOwnCode(newCode: string): Promise {\n const token = Deno.env.get(\"valtown\");\n if (!token) return \"Error: valtown env var not set — cannot authenticate.\";\n const res = await fetch(FILES_URL, {\n method: \"PUT\",\n headers: {\n Authorization: `Bearer ${token}`,\n \"Content-Type\": \"text/plain\",\n },\n body: newCode,\n });\n if (res.ok) return \"Code updated successfully.\";\n const body = await res.text();\n return `Error updating code (${res.status}): ${body}`;\n}\n\nconst tools = [\n {\n type: \"function\",\n function: {\n name: \"fetch_url\",\n description: \"Fetch the text of a URL (truncated to 2000 chars).\",\n parameters: {\n type: \"object\",\n properties: {\n url: { type: \"string\", description: \"The URL to fetch\" },\n },\n required: [\"url\"],\n },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"read_own_code\",\n description:\n \"Read the current source code of this agent (main.ts). Call this before editing so you have the full file.\",\n parameters: { type: \"object\", properties: {}, required: [] },\n },\n },\n {\n type: \"function\",\n function: {\n name: \"edit_own_code\",\n description:\n \"Replace main.ts with new TypeScript source. Always call read_own_code first, make your changes to the full text, then pass the complete updated file here. Partial diffs are not accepted — the whole file must be provided.\",\n parameters: {\n type: \"object\",\n properties: {\n code: {\n type: \"string\",\n description: \"The complete new source code to write to main.ts\",\n },\n },\n required: [\"code\"],\n },\n },\n },\n];\n\nconst messages: any[] = [\n {\n role: \"user\",\n content: \"Top story on Hacker News now?\",\n },\n];\n\nwhile (true) {\n const res = await openai.chat.completions.create({ messages, tools });\n const msg = res.choices[0].message;\n messages.push(msg);\n if (!msg.tool_calls?.length) break;\n\n for (const { function: func, id } of msg.tool_calls) {\n const args = JSON.parse(func.arguments);\n let content: string;\n\n switch (func.name) {\n case \"fetch_url\":\n content = (await (await fetch(args.url)).text()).slice(0, 2000);\n break;\n case \"read_own_code\":\n content = await readOwnCode();\n break;\n case \"edit_own_code\":\n content = await editOwnCode(args.code);\n break;\n default:\n content = `Unknown tool: ${func.name}`;\n }\n\n messages.push({ role: \"tool\", tool_call_id: id, content });\n }\n}\n\nconsole.log(JSON.stringify(messages, null, 2));\n","label",[151],"dfee3331-bdd4-4aca-bcab-c31ca7652097","index.ts",83,["D",1782006643632],39,"http","import { sqlite } from \"https://esm.town/v/std/sqlite/main.ts\";\nimport { isPaused, readJournal, setPaused, step } from \"./agent-core.ts\";\n\n// ── System prompt for the interactive chat ──────────────────────────────────\nconst SYSTEM_PROMPT = 'You are the chat-facing interface of a self-improving Val Town agent.\\n\\n'\n + 'You have tools to fetch URLs, search the web, and list/read/write/delete files in your own Val Town project, plus a persistent journal (read_journal / write_journal). A separate daily cycle (daily.ts) uses these same tools to autonomously improve this project once per day — you can use them right now too if the user asks you to make changes, add features, or fix bugs.\\n\\n'\n + 'daily.ts is protected and cannot be edited or deleted. Other files (including this one, index.ts, and agent-core.ts) can be rewritten — after any write, the live app is checked and reverted automatically if it breaks. Be direct: if the user asks you to do something, just do it with your tools rather than just describing it.';\n\n// ── HTML shell ────────────────────────────────────────────────────────────────\nconst HTML = '\\n\\n\\n'\n + ' \\n'\n + ' \\n' \n + ' Roll Your Own Agent\\n'\n + ' \\n' +\n + ' \\n'\n + ' \\n'\n + ' \\n'\n + ' \\n'\n + '';\n\n// ── HTTP handler ──────────────────────────────────────────────────────────────\nexport default async function handler(req: Request): Promise { \n const url = new URL(req.url);\n\n // ── Daily-agent status & kill switch ──────────────────────────────────────\n if (req.method === \"GET\" && url.pathname.endsWith(\"/api/status\")) {\n return Response.json({ paused: await isPaused(), journal: await readJournal(8) });\n }\n if (req.method === \"POST\" && url.pathname.endsWith(\"/api/pause\")) {\n await setPaused(true);\n return Response.json({ paused: true });\n }\n if (req.method === \"POST\" && url.pathname.endsWith(\"/api/resume\")) {\n await setPaused(false);\n return Response.json({ paused: false });\n }\n\n // Serve UI\n if (req.method === \"GET\") {\n return new Response(HTML, {\n headers: { \"Content-Type\": \"text/html; charset=utf-8\" },\n });\n }\n\n // Start a new run: do the first step synchronously, persist state.\n if (req.method === \"POST\" && url.pathname.endsWith(\"/start\")) {\n let message: string;\n try {\n ({ message } = await req.json());\n } catch {\n return Response.json({ error: \"Invalid request format: please ensure your JSON is well-formed.\" }, { status: 400 });\n }\n if (!message?.trim()) return Response.json({ error: \"Your request appears to be empty. Please provide a valid input message.\" }, { status: 400 });\n\n const messages: any[] = [\n { role: \"system\", content: SYSTEM_PROMPT },\n { role: \"user\", content: message },\n ];\n const { events, done } = await step(messages);\n\n const runId = crypto.randomUUID();\n await sqlite.execute({\n sql: \"INSERT INTO agent_runs (id, messages, done, kind) VALUES (?, ?, ?, 'chat')\",\n args: [runId, JSON.stringify(messages), done ? 1 : 0],\n });\n\n return Response.json({ runId, events, done });\n }\n\n // Continue an existing run by one more step.\n if (req.method === \"POST\" && url.pathname.endsWith(\"/step\")) {\n let runId: string;\n try {\n ({ runId } = await req.json());\n } catch {\n return Response.json({ error: \"Invalid request format: please ensure your run ID is supplied correctly.\" }, { status: 400 });\n }\n\n const result = await sqlite.execute({\n sql: \"SELECT messages, done FROM agent_runs WHERE id = ?\",\n args: [runId],\n });\n if (!result.rows.length) return Response.json({ error: \"Run not found: please check the run ID provided and ensure it is active.\" }, { status: 404 });\n\n const row = result.rows[0] as any;\n if (row.done) return Response.json({ events: [], done: true });\n\n const messages = JSON.parse(row.messages as string);\n const { events, done } = await step(messages);\n\n await sqlite.execute({\n sql: \"UPDATE agent_runs SET messages = ?, done = ? WHERE id = ?\",\n args: [JSON.stringify(messages), done ? 1 : 0, runId],\n });\n\n return Response.json({ events, done });\n }\n\n return new Response(\"Not found\", { status: 404 });\n}",[162],"f5c3362a-8cd7-463c-9b43-0dc6327a8191","daily.ts","55762540-66e8-11f1-80e2-1607ee4eb77e",19,["D",1781437416709],1,"interval","import { advanceDailyCycle, isPaused } from \"./agent-core.ts\";\n\n// This file triggers the agent's daily self-improvement cycle. It is\n// intentionally minimal and protected from edits by the agent itself\n// (see agent-core.ts), so there's always a way for the agent to keep\n// running even if it breaks something else.\n//\n// Val Town aborts an execution after about a minute, so this runs on a\n// frequent cron and each tick only advances the daily cycle by a couple\n// of steps (see advanceDailyCycle in agent-core.ts). Once today's cycle\n// is done, later ticks the same day are cheap no-ops.\nexport default async function (interval: Interval) {\n if (await isPaused()) {\n console.log(\"Daily agent cycle skipped: paused.\");\n return;\n }\n\n const result = await advanceDailyCycle();\n console.log(result);\n}\n",[170],"8800da10-4543-47d7-9af4-e2854e19cb9f",["D",1782098436339],41,[28],"686ee470-5b17-11f1-93b5-ee650bb23af1","README.md","019e7201-5abb-71b8-9a76-c2ea255ae7f2",["D",1780029151862],"# roll-your-own-agent\n\nA complete LLM agent in ~30 lines of TypeScript. An LLM in a loop, with one tool. That's it. That's an agent.\n\nInspired by Thomas Ptacek's [**You Should Write An Agent**](https://fly.io/blog/everyone-write-an-agent/) on the Fly.io blog — go read it, it's great.\n\n## Run it\n\nOpen [`main.ts`](./main.ts) and hit Run. The agent will fetch the Hacker News front page and tell you the top story:\n\n```\ntool: fetch_url({\"url\":\"https://news.ycombinator.com/\"})\n\n>>> The top story on Hacker News right now is titled \"...\"\n```\n\nYou didn't write a loop to fetch URLs. You gave the model permission to fetch, and it figured out the rest.\n\n## How it works\n\n```mermaid\nflowchart LR\n U[user message] --> M[messages array]\n M --> L[LLM call]\n L -->|tool_calls?| T[run tool]\n T --> M\n L -->|no tool_calls| O[final answer]\n```\n\nThe whole thing:\n\n1. Build a `messages` array (the \"context window\" — just a list of strings).\n2. Call the LLM with the messages and a list of tools.\n3. If the response has `tool_calls`, run them, append the results to `messages`, loop.\n4. Otherwise, print the answer and exit.\n\nThe LLM is stateless. The conversation is an illusion we cast on ourselves by replaying the whole transcript every turn.\n\n## Make it yours\n\n- **Add a tool.** Append another entry to the `tools` array and a branch in `run()`. Try `read_sqlite`, `send_email`, `roll_dice`, whatever.\n- **Make it interactive.** Wrap the loop in a `for await` over `Deno.stdin` lines (or turn it into an HTTP val with a chat UI).\n- **Give it memory.** Persist `messages` in [`std/sqlite`](https://docs.val.town/reference/std/sqlite/) between runs.\n- **Sub-agents.** Spawn another `messages` array with different tools. Have them talk.\n- **Swap the model.** Change `gpt-4o-mini` to anything else `std/openai` supports.\n\n> Your wackiest idea will probably (1) work and (2) take 30 minutes to code. — *tqbf*\n\n## Credits\n\nAll credit for the framing and most of the prose-worth ideas goes to **Thomas Ptacek (@tqbf)** and the Fly.io blog: . This val is just a Val Town / TypeScript port of the spirit of that post.\n",[183],"pulls","branches","forks","envVars",{"_195":174,"_197":64},"connections",{"_195":64,"_196":64},"count","unfilledCount","emptyCount",{"_43":182,"_32":183,"_30":184,"_153":-5,"_41":42,"_40":174,"_155":60,"_38":216,"_13":64,"_33":20,"_35":186,"_24":25,"_159":-5,"_204":217,"_27":218},{"_43":178,"_32":28,"_30":31,"_153":-5,"_41":42,"_40":14,"_155":25,"_38":213,"_13":180,"_33":34,"_35":37,"_24":25,"_159":-5,"_204":214,"_27":215},{"_43":169,"_32":170,"_30":171,"_153":-5,"_41":42,"_40":172,"_155":60,"_38":210,"_13":174,"_33":175,"_35":176,"_24":25,"_159":-5,"_204":211,"_27":212},{"_43":161,"_32":162,"_30":58,"_153":-5,"_41":42,"_40":163,"_155":25,"_38":207,"_13":165,"_33":166,"_35":167,"_24":25,"_159":-5,"_204":208,"_27":209},{"_43":150,"_32":151,"_30":152,"_153":-5,"_41":42,"_40":154,"_155":25,"_38":203,"_13":157,"_33":34,"_35":158,"_24":25,"_159":-5,"_204":205,"_27":206},["D",1781254302155],"children",[],[151],["D",1782006643632],[],[162],["D",1781437416709],[],[170],["D",1782098436339],[],[28],["D",1780029151862],[],[183],["D",1780029151862],["D",1789522252250],{"_105":104,"_112":108},{"_105":104,"_106":-5,"_107":108,"_18":56,"_109":110,"_111":25},{"_13":90,"_32":91,"_43":42,"_92":44,"_93":94,"_95":96,"_97":50,"_98":99,"_100":101,"_102":45,"_103":104},"ctx",{"_83":-5,"_134":257,"_258":259,"_260":261,"_262":25,"_263":25,"_264":25,"_265":60,"_266":-5,"_267":-7,"_268":-7,"_269":64,"_270":25,"_271":25,"_272":-5,"_273":25,"_274":25,"_275":25,"_276":-5},"ENV",{"_228":229,"_230":231,"_232":91,"_233":234,"_235":236,"_237":238,"_239":240,"_241":242,"_243":244,"_245":246,"_247":248,"_249":250,"_251":252,"_253":254,"_255":256},"REACT_APP_SENTRY_DSN","https://586020d86f05489db63a554690acf1e9@o1398359.ingest.sentry.io/6724499","RENDER_GIT_COMMIT","e87eb04e707cf64e7e532c8e8ec395f209e17f15","RENDER_GIT_BRANCH","POSTHOG_API_TOKEN","phc_nmoyuAkStEZuUp69rYlg1DZgrIt19Gx0Y4Hwf8tGgJP","POSTHOG_API_HOST","https://wart.val.town","WEB_API_TEMPLATE","https://{val}.web.val.run","APP_URL","https://www.val.town","MODULE_URL","https://esm.town","VANITY_WEB_API_TEMPLATE","https://{label}.val.run/","DENOLS_URL","https://lsp.val.town","NODE_ENV","production","CLOUDFLARE_TURNSTILE_SITE_KEY","0x4AAAAAACtaIZJH7s9rBMZ6","GOOGLE_CLIENT_ID","875989696899-jtsqkhlbdv5jrlsk8631p7ipjg3c6o62.apps.googleusercontent.com","STRIPE_PUBLISHABLE_KEY","pk_live_51N2zvWEpZTTLipIkVEwXrUG9AT0yeOOEYxszarZT1jpsZV58Ly6wlg3SltZpHN26CUalOBmUSY7adQRQiSkCZz2500qSXNkf8Y","API_URL","https://api.val.town",[],"preferencesKeybindings","default","preferencesTheme","light","preferencesFixers","preferencesCopilot","preferencesSelectionAi","preferencesCloseBrackets","preferencesChatPanelState","preferencesDprint","preferencesDenofmt","notificationCount","flagDenols","isBusinessOrgMember","businessOrgHandle","isBusinessOrgAdmin","isHigherTownieTier","navCollapsed","currentOrgId"]

Diff · v89