OpenAI Realtime API Voice Agent

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\n\n \n \n",[18,68],"pulls","branches","forks","envVars",{"_178":180,"_181":180},"connections",{"_178":26,"_179":26},"count","unfilledCount",2,"emptyCount",{"_33":159,"_13":18,"_66":74,"_43":-5,"_35":36,"_160":40,"_161":24,"_37":244,"_39":26,"_69":75,"_163":-5,"_70":30,"_164":-5,"_196":245,"_17":246},{"_33":167,"_13":68,"_66":67,"_43":74,"_35":36,"_160":40,"_161":24,"_37":241,"_39":26,"_69":21,"_163":169,"_70":30,"_164":-5,"_196":242,"_17":243},{"_33":237,"_13":215,"_66":209,"_43":-5,"_35":36,"_160":40,"_161":24,"_37":238,"_39":26,"_69":75,"_163":-5,"_70":30,"_164":-5,"_196":239,"_17":240},{"_33":230,"_13":231,"_66":232,"_43":209,"_35":36,"_160":40,"_161":24,"_37":233,"_39":26,"_69":211,"_163":234,"_70":30,"_164":-5,"_196":235,"_17":236},{"_33":223,"_13":224,"_66":225,"_43":209,"_35":36,"_160":40,"_161":24,"_37":226,"_39":26,"_69":211,"_163":227,"_70":30,"_164":-5,"_196":228,"_17":229},{"_33":216,"_13":217,"_66":218,"_43":209,"_35":36,"_160":40,"_161":24,"_37":219,"_39":26,"_69":211,"_163":220,"_70":30,"_164":-5,"_196":221,"_17":222},{"_33":206,"_13":207,"_66":208,"_43":209,"_35":36,"_160":40,"_161":24,"_37":210,"_39":26,"_69":211,"_163":212,"_70":30,"_164":-5,"_196":213,"_17":214},{"_33":199,"_13":200,"_66":201,"_43":-5,"_35":36,"_160":40,"_161":24,"_37":202,"_39":26,"_69":21,"_163":203,"_70":30,"_164":-5,"_196":204,"_17":205},{"_33":191,"_13":192,"_66":86,"_43":-5,"_35":36,"_160":40,"_161":24,"_37":193,"_39":26,"_69":194,"_163":195,"_70":30,"_164":-5,"_196":197,"_17":198},"fb3b3482-8a40-11f0-8416-0224a6c84d84","main.tsx",["D",1757067214507],"http","import { Hono } from \"npm:hono\";\nimport { parseVal, serveFile } from \"https://esm.town/v/std/utils/index.ts\";\n// import mcp from \"./routes/mcp.ts\";\nimport rtc from \"./routes/rtc.ts\";\nimport sip from \"./routes/sip.ts\";\nimport observer from \"./routes/observer.ts\";\n\nconst SOURCE_URL = parseVal(Deno.env.get(\"VALTOWN_ENTRYPOINT\")).links.self.val;\n\nconst app = new Hono();\napp.route(\"/rtc\", rtc);\napp.route(\"/sip\", sip);\napp.route(\"/observer\", observer);\n// app.route(\"/mcp\", mcp);\napp.get(\"/source\", (c) => c.redirect(SOURCE_URL));\n\napp.get(\"/\", () => serveFile(\"/frontend/index.html\"));\n\nexport default app.fetch;","children",[],[192],"fb3b3270-8a40-11f0-8416-0224a6c84d84","README.md","0199195d-fef9-72e2-a737-83e0089d3dde",["D",1757067214507],"# hello-realtime\n\nHello Realtime is a OpenAI Realtime app that supports both WebRTC and SIP\n(telephone) users. You can access the app via WebRTC at\nhttps://hello-realtime.val.run, or via SIP by calling 425-800-0042.\n\nThis demo shows off the new SIP API, the new all-in-one WebRTC API, and the new\nserver-side websocket interface.\n\nIf you remix the app, you'll just need to pop in your own OPENAI_API_KEY (from\nplatform.openai.com), and if you want SIP, the OPENAI_SIGNING_SECRET.\n\n## Architecture\n\n1. **WebRTC Flow**: Browser connects to frontend → creates WebRTC offer → `/rtc`\n endpoint handles SDP negotiation with OpenAI → observer monitors session\n2. **SIP Flow**: Phone calls trigger webhook → `/sip` endpoint verifies and\n accepts call → observer monitors session\n3. **Monitoring**: Observer establishes WebSocket connection to OpenAI for\n real-time session logging\n\n## Files\n\n- [`frontend/index.html`](./frontend/index.html) - Web interface with WebRTC\n client, audio handling, and real-time connection status\n- [`main.tsx`](./main.tsx) - Main Hono application entry point that sets up\n routing and serves the frontend\n- [`routes/observer.ts`](./routes/observer.ts) - WebSocket observer that\n connects to OpenAI's realtime API for session monitoring and logging\n- [`routes/rtc.ts`](./routes/rtc.ts) - WebRTC endpoint that handles SDP\n offer/answer negotiation with OpenAI's realtime API\n- [`routes/sip.ts`](./routes/sip.ts) - SIP webhook endpoint that verifies and\n accepts incoming phone calls via OpenAI's telephony integration\n- [`routes/utils.ts`](./routes/utils.ts) - Shared utilities including OpenAI API\n configuration, session setup, and voice agent instructions",[],[200],"fb3b2d5c-8a40-11f0-8416-0224a6c84d84","utils.ts","0199195d-fef9-72e2-a737-7b19ecfb926e","0199195d-fef9-72e2-a737-7e8852abf1f0",["D",1757067214507],"script","const MODEL = \"gpt-realtime\";\nconst INSTRUCTIONS = `\n Greet the user in English, and thank them for trying the new OpenAI Realtime API.\n Give them a brief summary based on the list below, and then ask if they have any questions.\n Answer questions using the information below. For questions outside this scope,\n apologize and say you can't help with that.\n ---\n Short summary:\n - The Realtime API is now generally available, and has improved instruction following, voice naturalness, and audio quality.\n There are two new voices and it's easier to develop for. There's also a new telephony integration for phone scenarios.\n Full list of improvements:\n - generally available (no longer in beta)\n - two new voices (Cedar and Marin)\n - improved instruction following\n - enhanced voice naturalness\n - higher audio quality\n - improved handling of alphanumerics (eg, properly understanding credit card and phone numbers)\n - support for the OpenAI Prompts API\n - support for MCP-based tools\n - auto-truncation to reduce context size\n - native telephony support, making it simple to connect voice calls to existing Realtime API applications\n - when using WebRTC, you can connect without needing an ephemeral token\n - when using WebRTC, you can now control sessions (including tool calls) from the server\n - when using WebRTC, you can now send video to the model, and it can respond based on what it sees\n - many helpful bugfixes!\n`;\nconst VOICE = \"marin\";\n\nconst OPENAI_API_KEY = Deno.env.get(\"OPENAI_API_KEY\");\nif (!OPENAI_API_KEY) {\n throw new Error(\"🔴 OpenAI API key not configured\");\n}\n\nexport function makeHeaders(contentType?: string) {\n const obj: Record = {\n Authorization: `Bearer ${OPENAI_API_KEY}`,\n };\n if (contentType) obj[\"Content-Type\"] = contentType;\n return obj;\n}\n\nexport function makeSession() {\n return {\n type: \"realtime\",\n model: MODEL,\n instructions: INSTRUCTIONS,\n audio: {\n input: { noise_reduction: { type: \"near_field\" } },\n output: { voice: VOICE },\n },\n };\n}",[],[215,207],"routes","fb3b2c62-8a40-11f0-8416-0224a6c84d84","sip.ts","0199195d-fef9-72e2-a737-7495aa09fc0c",["D",1757067214507],"import { Hono } from \"npm:hono\";\nimport { Webhook } from \"npm:svix\";\nimport { makeHeaders, makeSession } from \"./utils.ts\";\n\nconst sip = new Hono();\n\n// POST /sip : webhook endpoint\nsip.post(\"/\", async (c) => {\n // Verify the webhook.\n const OPENAI_SIGNING_SECRET = Deno.env.get(\"OPENAI_SIGNING_SECRET\");\n if (!OPENAI_SIGNING_SECRET) {\n console.error(\"🔴 webhook secret not configured\");\n return c.text(\"Internal error\", 500);\n }\n const webhook = new Webhook(OPENAI_SIGNING_SECRET);\n const bodyStr = await c.req.text();\n let callId: string | undefined;\n try {\n const headers = Object.fromEntries(c.req.raw.headers.entries());\n const payload: any = webhook.verify(bodyStr, headers);\n callId = payload.data.call_id;\n console.log(\"✅ verified webhook:\", callId);\n } catch (error) {\n console.error(`🔴 verify failed: ${error}`);\n return c.text(\"Invalid signature\", 401);\n }\n\n // Accept the call.\n const url = `https://api.openai.com/v1/realtime/calls/${callId}/accept`;\n const headers = makeHeaders(\"application/json\");\n const body = JSON.stringify(makeSession());\n const opts = { method: \"POST\", headers, body };\n const resp = await fetch(url, opts);\n if (!resp.ok) {\n const errText = await resp.text().catch(() => \"\");\n console.error(`🔴 accept failed: ${errText}`);\n return c.text(\"Internal error\", 500);\n }\n console.log(\"✅ call accepted:\", callId);\n\n // Kick off observer in the background (fire-and-forget).\n const selfUrl = new URL(c.req.url);\n fetch(`${selfUrl.origin}/observer/${callId}`, { method: \"POST\" })\n .catch((e) => console.error(\"observer trigger failed:\", e));\n\n return c.newResponse(null);\n});\n\nexport default sip;",[],[215,217],"fb3b2b36-8a40-11f0-8416-0224a6c84d84","rtc.ts","0199195d-fef9-72e2-a737-717fe040a6b0",["D",1757067214507],"import { Hono } from \"npm:hono\";\nimport { makeHeaders, makeSession } from \"./utils.ts\";\n\nconst rtc = new Hono();\n\n// POST /rtc : create a new call\nrtc.post(\"/\", async (c) => {\n // Create the call.\n const url = \"https://api.openai.com/v1/realtime/calls\";\n const headers = makeHeaders();\n const fd = new FormData();\n fd.set(\"sdp\", await c.req.text());\n fd.set(\"session\", JSON.stringify(makeSession()));\n const opts = { method: \"POST\", headers, body: fd };\n const resp = await fetch(url, opts);\n if (!resp.ok) {\n const errText = await resp.text().catch(() => \"\");\n console.error(`🔴 start call failed: ${resp.status} ${errText}`);\n return c.text(\"Internal error\", 500);\n }\n\n const contentType = resp.headers.get(\"Content-Type\");\n const location = resp.headers.get(\"Location\");\n const callId = location?.split(\"/\").pop();\n console.log(\"✅ call created:\", callId);\n\n // Kick off observer in the background (fire-and-forget).\n const selfUrl = new URL(c.req.url);\n fetch(`${selfUrl.origin}/observer/${callId}`, { method: \"POST\" })\n .catch(() => {}); // catch to not crash the process\n\n return c.newResponse(resp.body, {\n headers: { \"Content-Type\": contentType },\n });\n});\n\nexport default rtc;",[],[215,224],"fb3b2a0a-8a40-11f0-8416-0224a6c84d84","observer.ts","0199195d-fef9-72e2-a737-6ce315961e06",["D",1757067214507],"import { Hono } from \"npm:hono\";\nimport WebSocket from \"npm:ws\";\nimport { makeHeaders } from \"./utils.ts\";\n\nconst observer = new Hono();\n\n// POST /observer/:callId : self-connect to establish a web socket\nobserver.post(\"/:callId\", async (c) => {\n const callId = c.req.param(\"callId\");\n const url = `wss://api.openai.com/v1/realtime?call_id=${callId}`;\n const ws = new WebSocket(url, { headers: makeHeaders() });\n ws.on(\"open\", () => {\n console.log(\"✅ websocket connected\");\n setTimeout(() => ws.send(JSON.stringify({ type: \"response.create\" })), 250);\n });\n ws.on(\"message\", (data /*, isBinary */) => {\n const message = JSON.parse(data);\n if (message.type !== \"response.audio_transcript.delta\") {\n console.log(message);\n }\n });\n ws.on(\"error\", (err: Error) => {\n console.error(`🔴 websocket failed: ${err.message}`);\n });\n\n // Respond immediately; WS continues in background\n return c.newResponse(null);\n});\n\nexport default observer;",[],[215,231],"fb3b30e0-8a40-11f0-8416-0224a6c84d84",["D",1757067214507],[185,186,187,188],[215],["D",1757067214507],[],[18,68],["D",1757067214507],[183],[18],["D",1757067214507],{"_11":12,"_125":73},{"_11":12,"_121":-5,"_72":73,"_31":71,"_122":123,"_124":30},{"_39":40,"_13":16,"_33":36,"_110":77,"_111":63,"_112":113,"_114":81,"_115":116,"_117":118,"_119":14,"_120":12},"ctx",{"_52":-5,"_146":284,"_285":286,"_287":288,"_289":30,"_290":30,"_291":30,"_292":24,"_293":-5,"_294":-7,"_295":-7,"_296":26,"_297":30,"_298":30,"_299":-5,"_300":30,"_301":30,"_302":30,"_303":-5},"ENV",{"_255":256,"_257":258,"_259":16,"_260":261,"_262":263,"_264":265,"_266":267,"_268":269,"_270":271,"_272":273,"_274":275,"_276":277,"_278":279,"_280":281,"_282":283},"REACT_APP_SENTRY_DSN","https://586020d86f05489db63a554690acf1e9@o1398359.ingest.sentry.io/6724499","RENDER_GIT_COMMIT","fdb67791413f4386b4dbf18f354029a617f6160f","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"]

Realtime Agent

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