\n\n

TownCar

Your personal driver for any task.
Tell us the destination, we'll handle the journey.

\n \n

\n\n

Your Itinerary

\n\n \n \n \n\n \n \n \n `;\n}\n\n// --- BACKEND: The Hono API Server ---\nconst app = new Hono();\n\nasync function callOpenAI(c, messages, response_format = { type: \"text\" }) {\n const openai = new OpenAI();\n const completion = await openai.chat.completions.create({\n model: \"gpt-4o\",\n messages: messages,\n response_format: response_format,\n });\n if (!completion || !completion.choices || completion.choices.length === 0) {\n throw new Error(\"The AI service returned an invalid or empty response.\");\n }\n return completion.choices[0].message.content;\n}\n\n// API: Plan Itinerary\napp.post(\"/api/plan-itinerary\", async (c) => {\n const { goal } = await c.req.json();\n try {\n const messages = [{\n role: \"system\",\n content: META_PROMPTS.ROUTE_PLANNER.replace(\"{{goal}}\", goal),\n }];\n const planJson = await callOpenAI(c, messages, { type: \"json_object\" });\n return c.json(JSON.parse(planJson));\n } catch (e) {\n console.warn(\n \"Initial route planning failed. Retrying with a simpler prompt...\",\n e,\n );\n try {\n const retryMessages = [{\n role: \"system\",\n content: META_PROMPTS.ROUTE_PLANNER_RETRY.replace(\"{{goal}}\", goal),\n }];\n const retryPlanJson = await callOpenAI(c, retryMessages, {\n type: \"json_object\",\n });\n return c.json(JSON.parse(retryPlanJson));\n } catch (retryError) {\n console.error(\"Route planning retry failed:\", retryError);\n return c.json({\n details:\n \"The AI failed to chart a course. Please try rephrasing your destination.\",\n }, 500);\n }\n }\n});\n\n// API: Prepare for Stop (Generates UI Schema)\napp.post(\"/api/prepare-stop\", async (c) => {\n try {\n const { task, context } = await c.req.json();\n const contextString = JSON.stringify(context, null, 2);\n const architectMessages = [{\n role: \"system\",\n content: META_PROMPTS.STOP_ARCHITECT.replace(\"{{task}}\", task).replace(\n \"{{context}}\",\n contextString,\n ),\n }];\n const specJson = await callOpenAI(c, architectMessages, {\n type: \"json_object\",\n });\n const spec = JSON.parse(specJson);\n let uiJson = '{\"inputs\":[]}';\n if (spec.inputs && spec.inputs.length > 0) {\n const uiBuilderMessages = [{\n role: \"system\",\n content: META_PROMPTS.UI_BUILDER.replace(\"{{spec}}\", specJson),\n }];\n uiJson = await callOpenAI(c, uiBuilderMessages, { type: \"json_object\" });\n }\n return c.json({ taskSpecification: spec, uiSchema: JSON.parse(uiJson) });\n } catch (e) {\n console.error(\"Stop preparation failed:\", e);\n return c.json({\n details: `The AI failed to prepare for the stop. Error: ${e.message}`,\n }, 500);\n }\n});\n\n// API: Drive to Stop (Executes Task and Streams Output)\napp.post(\"/api/drive-to-stop\", async (c) => {\n const { readable, writable } = new TransformStream();\n const writer = writable.getWriter();\n const textEncoder = new TextEncoder();\n new Promise(async (resolve, reject) => {\n try {\n const { task, context, inputs } = await c.req.json();\n const contextString = JSON.stringify(context, null, 2);\n const specJson = await callOpenAI(c, [{\n role: \"system\",\n content: META_PROMPTS.STOP_ARCHITECT.replace(\"{{task}}\", task).replace(\n \"{{context}}\",\n contextString,\n ),\n }], { type: \"json_object\" });\n let executionPrompt = await callOpenAI(c, [{\n role: \"system\",\n content: META_PROMPTS.LOGIC_WEAVER.replace(\"{{spec}}\", specJson)\n .replace(\"{{context}}\", contextString),\n }]);\n for (const [key, value] of Object.entries(inputs)) {\n executionPrompt = executionPrompt.replace(\n new RegExp(`\\\\{\\\\{\\\\s*${key}\\\\s*\\\\}\\\\}`, \"g\"),\n value,\n );\n }\n const openai = new OpenAI();\n const aiStream = await openai.chat.completions.create({\n model: \"gpt-4o\",\n messages: [{ role: \"user\", content: executionPrompt }],\n stream: true,\n });\n for await (const chunk of aiStream) {\n const content = chunk.choices[0]?.delta?.content || \"\";\n if (content) {\n await writer.write(textEncoder.encode(content));\n }\n }\n await writer.close();\n resolve();\n } catch (e) {\n console.error(\"Driving to stop (execution stream) failed:\", e);\n // We'll handle this on the client-side via the HTTP status code.\n // Trying to write an error to a potentially broken stream is unreliable.\n reject(e);\n // Ensure writer is closed on error\n try {\n await writer.close();\n } catch {}\n }\n });\n return new Response(readable, {\n headers: { \"Content-Type\": \"text/plain; charset=utf-8\" },\n });\n});\n\n// Serve the main HTML file\napp.get(\"/\", (c) => c.html(generateHtml(c.req.url)));\n\nexport default app.fetch;","deleted","label","ride",[98],"permalink","https://www.val.town/x/real/towncar2/code/main.tsx","extension","actionData","errors"]