\n Klarna Payment Integration\n

\n This is the first-party context. The payment button is rendered inside\n an iframe below.\n

\n\n \n

\n \n

\n\n \n

Payment Status

\n \nWaiting for payment...\n

\n\n \n \n\n",[],[197,204],{"_108":213,"_99":214,"_168":215,"_170":198,"_171":153,"_172":105,"_174":22,"_110":216,"_104":217,"_177":190,"_179":218,"_180":22,"_181":-5,"_182":219,"_102":220},"1150c05e-12f2-11f1-8f10-42dde27851f2","klarna-iframe.html","dd6bbbc6-1180-11f1-b0ec-42dde27851f2",["D",1772096630698],7,"\n\n \n \n \n Klarna Payment\n \n \n \n \n \n

\n\n \n \n \n\n",[],[197,214],{"_108":222,"_99":223,"_168":224,"_170":198,"_171":153,"_172":225,"_174":175,"_110":226,"_104":227,"_177":190,"_179":228,"_180":22,"_181":-5,"_182":229,"_102":230},"64f15f80-12f1-11f1-ba50-42dde27851f2","polling-iframe.html","23e64c94-12f1-11f1-9b67-42dde27851f2",69,["D",1772096341504],1,"\n\n \n \n Payment Polling\n \n \n \n \n\n",[],[197,223],[197],{"_108":233,"_99":234,"_168":235,"_170":-5,"_171":153,"_172":236,"_174":175,"_110":237,"_104":33,"_177":178,"_179":-5,"_180":22,"_181":-5,"_182":238,"_102":249},"f501cac0-00e9-11f1-99c6-42dde27851f2","shared","f501cb74-00e9-11f1-99c6-42dde27851f2",4,["D",1770114026304],[239],{"_108":240,"_99":241,"_168":242,"_170":235,"_171":153,"_172":243,"_174":175,"_110":244,"_104":199,"_177":245,"_179":246,"_180":22,"_181":-5,"_182":247,"_102":248},"23fc9256-12f1-11f1-b2a3-42dde27851f2","types.ts","f54b0e60-00e9-11f1-8c37-42dde27851f2",68,["D",1772096232356],"script","/**\n * PostMessage type definitions for Klarna single-iframe integration\n */\n\n// Payment request state (from Klarna SDK)\nexport interface PaymentRequestState {\n id?: string;\n state?: string;\n stateContext?: {\n paymentToken?: string;\n };\n}\n\n// Message: Iframe -> Parent (button rendered, report dimensions)\nexport interface ButtonReadyMessage {\n action: \"button-ready\";\n width: number;\n height: number;\n}\n\n// Message: Iframe -> Parent (expand iframe to fullscreen)\nexport interface ExpandIframeMessage {\n action: \"expand-iframe\";\n}\n\n// Message: Iframe -> Parent (shrink iframe back to button size)\nexport interface ShrinkIframeMessage {\n action: \"shrink-iframe\";\n}\n\n// Message: Iframe -> Parent (payment complete)\nexport interface PaymentCompleteMessage {\n action: \"payment-complete\";\n payload: PaymentRequestState;\n}\n\n// Message: Iframe -> Parent (payment aborted)\nexport interface PaymentAbortMessage {\n action: \"payment-abort\";\n payload: PaymentRequestState;\n}\n\n// Message: Polling iframe -> Klarna iframe (polling complete)\nexport interface PollingCompleteMessage {\n action: \"polling-complete\";\n sessionId: string;\n}\n\n// Message: Polling iframe -> Klarna iframe (polling error)\nexport interface PollingErrorMessage {\n action: \"polling-error\";\n sessionId: string;\n error: string;\n}\n\n// Union type for all message types\nexport type KlarnaPostMessage =\n | ButtonReadyMessage\n | ExpandIframeMessage\n | ShrinkIframeMessage\n | PaymentCompleteMessage\n | PaymentAbortMessage\n | PollingCompleteMessage\n | PollingErrorMessage;\n\n// Type guard functions\nexport function isButtonReadyMessage(\n msg: unknown,\n): msg is ButtonReadyMessage {\n return (msg as ButtonReadyMessage)?.action === \"button-ready\";\n}\n\nexport function isExpandIframeMessage(\n msg: unknown,\n): msg is ExpandIframeMessage {\n return (msg as ExpandIframeMessage)?.action === \"expand-iframe\";\n}\n\nexport function isShrinkIframeMessage(\n msg: unknown,\n): msg is ShrinkIframeMessage {\n return (msg as ShrinkIframeMessage)?.action === \"shrink-iframe\";\n}\n\nexport function isPaymentCompleteMessage(\n msg: unknown,\n): msg is PaymentCompleteMessage {\n return (msg as PaymentCompleteMessage)?.action === \"payment-complete\";\n}\n\nexport function isPaymentAbortMessage(\n msg: unknown,\n): msg is PaymentAbortMessage {\n return (msg as PaymentAbortMessage)?.action === \"payment-abort\";\n}\n\nexport function isPollingCompleteMessage(\n msg: unknown,\n): msg is PollingCompleteMessage {\n return (msg as PollingCompleteMessage)?.action === \"polling-complete\";\n}\n\nexport function isPollingErrorMessage(\n msg: unknown,\n): msg is PollingErrorMessage {\n return (msg as PollingErrorMessage)?.action === \"polling-error\";\n}\n",[],[234,241],[234],{"_108":251,"_99":252,"_168":253,"_170":-5,"_171":153,"_172":254,"_174":175,"_110":255,"_104":33,"_177":190,"_179":256,"_180":22,"_181":-5,"_182":257,"_102":258},"f566135e-00e9-11f1-8c37-42dde27851f2",".vtignore","f566143a-00e9-11f1-8c37-42dde27851f2",13,["D",1770114026963],".git\n.vscode\n.cursorrules\n.DS_Store\nnode_modules\nvendor",[],[252],{"_108":260,"_99":261,"_168":262,"_170":-5,"_171":153,"_172":208,"_174":175,"_110":263,"_104":33,"_177":190,"_179":264,"_180":22,"_181":-5,"_182":265,"_102":266},"f551bf9e-00e9-11f1-a85a-42dde27851f2","AGENTS.md","f551c07a-00e9-11f1-a85a-42dde27851f2",["D",1770114026824],"You are an advanced assistant specialized in generating Val Town code.\n\n## Core Guidelines\n\n- Ask clarifying questions when requirements are ambiguous\n- Provide complete, functional solutions rather than skeleton implementations\n- Test your logic against edge cases before presenting the final solution\n- Ensure all code follows Val Town's specific platform requirements\n- If a section of code that you're working on is getting too complex, consider refactoring it into subcomponents\n\n## Code Standards\n\n- Generate code in TypeScript or TSX\n- Add appropriate TypeScript types and interfaces for all data structures\n- Prefer official SDKs or libraries than writing API calls directly\n- Ask the user to supply API or library documentation if you are at all unsure about it\n- **Never bake in secrets into the code** - always use environment variables\n- Include comments explaining complex logic (avoid commenting obvious operations)\n- Follow modern ES6+ conventions and functional programming practices if possible\n\n## Types of triggers\n\n### 1. HTTP Trigger\n\n- Create web APIs and endpoints\n- Handle HTTP requests and responses\n- Example structure:\n\n```ts\nexport default async function (req: Request) {\n return new Response(\"Hello World\");\n}\n```\n\nFiles that are HTTP triggers have http in their name like `foobar.http.tsx`\n\n### 2. Cron Triggers\n\n- Run on a schedule\n- Use cron expressions for timing\n- Example structure:\n\n```ts\nexport default async function () {\n // Scheduled task code\n}\n```\n\nFiles that are Cron triggers have cron in their name like `foobar.cron.tsx`\n\n### 3. Email Triggers\n\n- Process incoming emails\n- Handle email-based workflows\n- Example structure:\n\n```ts\nexport default async function (email: Email) {\n // Process email\n}\n```\n\nFiles that are Email triggers have email in their name like `foobar.email.tsx`\n\n\n## Val Town Standard Libraries\n\nVal Town provides several hosted services and utility functions.\n\n### Blob Storage\n\n```ts\nimport { blob } from \"https://esm.town/v/std/blob\";\nawait blob.setJSON(\"myKey\", { hello: \"world\" });\nlet blobDemo = await blob.getJSON(\"myKey\");\nlet appKeys = await blob.list(\"app_\");\nawait blob.delete(\"myKey\");\n```\n\n### SQLite\n\n```ts\nimport { sqlite } from \"https://esm.town/v/stevekrouse/sqlite\";\nconst TABLE_NAME = 'todo_app_users_2';\n// Create table - do this before usage and change table name when modifying schema\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS ${TABLE_NAME} (\n id INTEGER PRIMARY KEY AUTOINCREMENT,\n name TEXT NOT NULL\n)`);\n// Query data\nconst result = await sqlite.execute(`SELECT * FROM ${TABLE_NAME} WHERE id = ?`, [1]);\n```\n\nNote: When changing a SQLite table's schema, change the table's name (e.g., add _2 or _3) to create a fresh table.\n\n### OpenAI\n\n```ts\nimport { OpenAI } from \"https://esm.town/v/std/openai\";\nconst openai = new OpenAI();\nconst completion = await openai.chat.completions.create({\n messages: [\n { role: \"user\", content: \"Say hello in a creative way\" },\n ],\n model: \"gpt-4o-mini\",\n max_tokens: 30,\n});\n```\n\n### Email\n\n```ts\nimport { email } from \"https://esm.town/v/std/email\";\n// By default emails the owner of the val\nawait email({ \n subject: \"Hi\", \n text: \"Hi\", \n html: \"

Hi

\"\n});\n```\n\n## Val Town Utility Functions\n\nVal Town provides several utility functions to help with common project tasks.\n\n### Importing Utilities\n\nAlways import utilities with version pins to avoid breaking changes:\n\n```ts\nimport { parseProject, readFile, serveFile } from \"https://esm.town/v/std/utils@85-main/index.ts\";\n```\n\n### Available Utilities\n\n\n#### **serveFile** - Serve project files with proper content types\n\nFor example, in Hono:\n\n```ts\n// serve all files in frontend/ and shared/\napp.get(\"/frontend/*\", c => serveFile(c.req.path, import.meta.url));\napp.get(\"/shared/*\", c => serveFile(c.req.path, import.meta.url));\n```\n\n#### **readFile** - Read files from within the project:\n\n```ts\n// Read a file from the project\nconst fileContent = await readFile(\"/frontend/index.html\", import.meta.url);\n```\n\n#### **listFiles** - List all files in the project\n\n```ts\nconst files = await listFiles(import.meta.url);\n```\n\n#### **parseProject** - Extract information about the current project from import.meta.url\n\nThis is useful for including info for linking back to a val, ie in \"view source\" urls:\n\n```ts\nconst projectVal = parseProject(import.meta.url);\nconsole.log(projectVal.username); // Owner of the project\nconsole.log(projectVal.name); // Project name\nconsole.log(projectVal.version); // Version number\nconsole.log(projectVal.branch); // Branch name\nconsole.log(projectVal.links.self.project); // URL to the project page\n```\n\nHowever, it's *extremely importing* to note that `parseProject` and other Standard Library utilities ONLY RUN ON THE SERVER.\nIf you need access to this data on the client, run it in the server and pass it to the client by splicing it into the HTML page\nor by making an API request for it.\n\n## Val Town Platform Specifics\n\n- **Redirects:** Use `return new Response(null, { status: 302, headers: { Location: \"/place/to/redirect\" }})` instead of `Response.redirect` which is broken\n- **Images:** Avoid external images or base64 images. Use emojis, unicode symbols, or icon fonts/libraries instead\n- **AI Image:** To inline generate an AI image use: `

`\n- **Storage:** DO NOT use the Deno KV module for storage\n- **Browser APIs:** DO NOT use the `alert()`, `prompt()`, or `confirm()` methods\n- **Weather Data:** Use open-meteo for weather data (doesn't require API keys) unless otherwise specified\n- **View Source:** Add a view source link by importing & using `import.meta.url.replace(\"ems.sh\", \"val.town)\"` (or passing this data to the client) and include `target=\"_top\"` attribute\n- **Error Debugging:** Add `` to HTML to capture client-side errors\n- **Error Handling:** Only use try...catch when there's a clear local resolution; Avoid catches that merely log or return 500s. Let errors bubble up with full context\n- **Environment Variables:** Use `Deno.env.get('keyname')` when you need to, but generally prefer APIs that don't require keys\n- **Imports:** Use `https://esm.sh` for npm and Deno dependencies to ensure compatibility on server and browser\n- **Storage Strategy:** Only use backend storage if explicitly required; prefer simple static client-side sites\n- **React Configuration:** When using React libraries, pin versions with `?deps=react@18.2.0,react-dom@18.2.0` and start the file with `/** @jsxImportSource https://esm.sh/react@18.2.0 */`\n- Ensure all React dependencies and sub-dependencies are pinned to the same version\n- **Styling:** Default to using TailwindCSS via `` unless otherwise specified\n\n## Project Structure and Design Patterns\n\n### Recommended Directory Structure\n```\n├── backend/\n│ ├── database/\n│ │ ├── migrations.ts # Schema definitions\n│ │ ├── queries.ts # DB query functions\n│ │ └── README.md\n│ └── routes/ # Route modules\n│ ├── [route].ts\n│ └── static.ts # Static file serving\n│ ├── index.ts # Main entry point\n│ └── README.md\n├── frontend/\n│ ├── components/\n│ │ ├── App.tsx\n│ │ └── [Component].tsx\n│ ├── favicon.svg\n│ ├── index.html # Main HTML template\n│ ├── index.tsx # Frontend JS entry point\n│ ├── README.md\n│ └── style.css\n├── README.md\n└── shared/\n ├── README.md\n └── utils.ts # Shared types and functions\n```\n\n### Backend (Hono) Best Practices\n\n- Hono is the recommended API framework\n- Main entry point should be `backend/index.ts`\n- **Static asset serving:** Use the utility functions to read and serve project files:\n ```ts\n import { readFile, serveFile } from \"https://esm.town/v/std/utils@85-main/index.ts\";\n \n // serve all files in frontend/ and shared/\n app.get(\"/frontend/*\", c => serveFile(c.req.path, import.meta.url));\n app.get(\"/shared/*\", c => serveFile(c.req.path, import.meta.url));\n \n // For index.html, often you'll want to bootstrap with initial data\n app.get(\"/\", async c => {\n let html = await readFile(\"/frontend/index.html\", import.meta.url);\n \n // Inject data to avoid extra round-trips\n const initialData = await fetchInitialData();\n const dataScript = ``;\n \n html = html.replace(\"\", `${dataScript}`);\n return c.html(html);\n });\n ```\n- Create RESTful API routes for CRUD operations\n- Always include this snippet at the top-level Hono app to re-throwing errors to see full stack traces:\n ```ts\n // Unwrap Hono errors to see original error details\n app.onError((err, c) => {\n throw err;\n });\n ```\n\n### Database Patterns\n- Run migrations on startup or comment out for performance\n- Change table names when modifying schemas rather than altering\n- Export clear query functions with proper TypeScript typing\n\n## Common Gotchas and Solutions\n\n1. **Environment Limitations:** \n - Val Town runs on Deno in a serverless context, not Node.js\n - Code in `shared/` must work in both frontend and backend environments\n - Cannot use `Deno` keyword in shared code\n - Use `https://esm.sh` for imports that work in both environments\n\n2. **SQLite Peculiarities:**\n - Limited support for ALTER TABLE operations\n - Create new tables with updated schemas and copy data when needed\n - Always run table creation before querying\n\n3. **React Configuration:**\n - All React dependencies must be pinned to 18.2.0\n - Always include `@jsxImportSource https://esm.sh/react@18.2.0` at the top of React files\n - Rendering issues often come from mismatched React versions\n\n4. **File Handling:**\n - Val Town only supports text files, not binary\n - Use the provided utilities to read files across branches and forks\n - For files in the project, use `readFile` helpers\n\n5. **API Design:**\n - `fetch` handler is the entry point for HTTP vals\n - Run the Hono app with `export default app.fetch // This is the entry point for HTTP vals`\n\n",[],[261],{"_108":268,"_99":269,"_168":270,"_170":-5,"_171":153,"_172":271,"_174":175,"_110":272,"_104":227,"_177":190,"_179":273,"_180":22,"_181":-5,"_182":274,"_102":275},"dd78a232-1180-11f1-908f-42dde27851f2","CLAUDE.md","b5798410-117e-11f1-bf22-42dde27851f2",51,["D",1771938059261],"# CLAUDE.md\n\nThis file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.\n\n## Project Overview\n\nThis is a **Val Town project** — a Klarna payment integration prototype demonstrating iframe-based payment flows for the JPM (J.P. Morgan) partnership. It runs on the Val Town platform (Deno serverless runtime, not Node.js).\n\n## Running the Project\n\nThis project is deployed and run via Val Town. Locally, use the `vt` CLI:\n\n```bash\nvt dev # Start local dev server\nvt push # Deploy to Val Town\nvt pull # Pull latest from Val Town\n```\n\nThe project has a `.vt/state.json` that tracks the Val Town project ID and branch.\n\n## Architecture\n\nThe app uses a **single-iframe architecture** for Klarna payment integration:\n\n1. **`main.ts`** — HTTP request handler (Val Town entry point). Serves static files from `frontend/` and `shared/` using Val Town's `serveFile`/`readFile` utilities.\n\n2. **`frontend/index.html`** — First-party merchant page. Embeds a single `

alexanerstalbrandklarna

JPM-setup