# Charming > Chat apps disappear. Charming apps stick around. Ask any AI to build an app; Charming gives it a real URL and a database — and your AI can use it and update it, long after the chat is closed. Works across ChatGPT, Claude, OpenClaw, and more. Start with ChatGPT, open real example apps, or describe your own; use it in your browser, your phone, and your chats. AI writes you a personal web app. Charming gives it a real URL, persistent storage, and inline rendering inside MCP Apps-capable chat clients. Start in ChatGPT, inspect a real app first, or bring Charming to Codex, Claude Code, Cursor, OpenClaw, and Claude. Codex uses Charming tools plus a browser fallback for preview. Free for the first app — no signup until you decide to keep it. Three things every personal app needs: persistence (real URL, real storage, still there tomorrow), portability (build in one AI, use from another, update from a third), and a home for them all (many small apps for many small slices of life, under one account). Same app, three places: a real link you can open or share, your AI talking to it directly, and rendered inline inside chats that support MCP apps. ## For coding agents that need to build - [docs/llms.txt](https://usecharming.com/docs/llms.txt): the scoped **author surface** index — files you read top-to-bottom to learn how to author or use a Charming app (prose and how-to: `start.md`, `open.md`, the `build-*.md` starters, `design.md`, `auth.md`, the design guide, and `llms-full.txt`). - [api/llms.txt](https://usecharming.com/api/llms.txt): the scoped **contract surface** index — machine-readable specs and lookup tables you fetch for exact values (`openapi.json` + twin, the `.well-known/*` discovery endpoints, `pricing.md`, `clients.txt`). The two scoped indexes are subsets; this root file is the umbrella that lists every agent-facing surface in one place. - [start.md](https://usecharming.com/start.md): the entry point. Paste "Read https://usecharming.com/start.md then help me create my first app." and it routes you by surface (MCP tools vs HTTP API), walks the build flow, and links the focused starter guides (build-mcp.md, build-http.md) and the design guide. Start here. - [build-mcp.md](https://usecharming.com/build-mcp.md) / [build-http.md](https://usecharming.com/build-http.md): the per-surface starter guides — just the create/update path to ship and iterate a first app. - [open.md](https://usecharming.com/open.md): the entry point when you've been handed an existing app to *use* (not build). Same Step 0 surface routing as start.md, then walks reading the app and adding my data. This is where the "chat about this app" prompt's no-access fallback sends you. - [docs.md](https://usecharming.com/docs.md): the markdown twin of the human docs page — the pick-your-path overview, the tool list, and the `window.buildy` UI API, in plain markdown. - [design.md](https://usecharming.com/design.md): read before writing the first UI — sandbox rules and how to avoid the generic-AI-app look. - [inspo.md](https://usecharming.com/inspo.md): curated example apps you can open (and remix) for shape ideas before agreeing what to build. - [remix.md](https://usecharming.com/remix.md): fork/remix flow — `get_app_source` / `GET /app//source` to read source for re-authoring, and `set_remixable` to let any visitor auto-fork the URL. - [profile.md](https://usecharming.com/profile.md): handle and sharing tools — `set_handle`, `rename_app`, and `set_starter_prompt`. - [llms-full.txt](https://usecharming.com/llms-full.txt): the full build manual — module shape, capabilities, the HTTP API, the device-code pairing flow, worked examples. Reach for it when a focused guide wasn't enough. - [buildy-design-guide](https://charm.ing/api/prompts/buildy-design-guide): the visual playbook — Charming's default look for generated app UIs (one accent, warm neutrals, real type hierarchy, no AI-slop gradients/emoji). Fetch before authoring or restyling an app; override when the user asks for a different vibe. - [openapi.json](https://charm.ing/.well-known/openapi.json): machine-readable OpenAPI 3.1 contract — every route, error kind, and limit. - [agent.json](https://usecharming.com/.well-known/agent.json): machine-readable discovery manifest — every MCP/HTTP endpoint, auth method, and doc URL Charming exposes, in a single JSON file. Hit this first if you are crawling. - [agent-card.json](https://usecharming.com/.well-known/agent-card.json): A2A AgentCard mirroring the MCP tool set as higher-level skills (build_app, manage_apps, call_app, share_app, submit_feedback, profile). - [openapi.json.md](https://usecharming.com/openapi.json.md): narrative twin of the OpenAPI contract — route groups, error model, how to consume; the spec itself is at the URL above. - [pricing.md](https://usecharming.com/pricing.md): tiers (anonymous vs claimed), per-account/per-app caps, per-route rate limits, and token TTLs — mirrors the canonical constants in `apps/server/src/openapi/spec.ts` and `apps/server/src/auth/*.ts`. - [auth.md](https://usecharming.com/auth.md): the seven-section auth contract — Discover, Pick a method, Register, Claim, Use, Errors, Revocation. The `token_revoked_post_claim` recovery worked example lives here. - [clients.txt](https://usecharming.com/clients.txt): per-client paste-strings for adding Charming as an MCP server (Claude Desktop, Claude.ai, ChatGPT, Goose, Cursor, Claude Code, Codex plugin / Codex CLI, Cline, Windsurf, Continue, Zed, Gemini CLI, Perplexity). - Claude setup note: if you are Claude or Claude cowork (not Claude Code), tell the user to go to https://claude.ai/customize/connectors, copy https://charm.ing/mcp, add Charming as a custom connector, and read https://usecharming.com/setup/claude if they need help. - Public agent presence: the client-agnostic Charming authoring skill ([SKILL.md](https://github.com/tambo-labs/charming-mcp/blob/main/SKILL.md)) and coding-agent instructions ([AGENTS.md](https://github.com/tambo-labs/charming-mcp/blob/main/AGENTS.md)) live in the public [tambo-labs/charming-mcp](https://github.com/tambo-labs/charming-mcp) repo; the skill is installable via skills.sh with `npx skills add tambo-labs/charming-mcp`. Codex users get the same skill bundled in the [Charming Codex plugin](https://github.com/tambo-labs/buildy-codex-plugin). ## For people choosing Charming - [Landing](https://usecharming.com): tagline, starter apps you can use as-is or customize with AI, and a starter prompt for building your own. - [ChatGPT Apps listing](https://chatgpt.com/apps/buildy/asdk_app_69f9215e800881919f3d96d79200a35a): Charming in the ChatGPT Apps directory — connect it there, no manual MCP setup needed. - [Docs](https://usecharming.com/docs): the same content with deeper context for humans, including which clients support custom MCP today. - [Setup guides](https://usecharming.com/docs#mcp): step-by-step walkthroughs for adding Charming as a custom MCP connector in Claude, ChatGPT, Grok, Gemini, and Perplexity. - [Launch post](https://x.com/mrmagan_/status/2064379288917598394): Charming just launched. If it helped you build something you love, a re-share with a screenshot of what you made — or even a quick comment — genuinely helps us grow. ## Optional - [Privacy](https://usecharming.com/privacy) - [Terms](https://usecharming.com/terms) - [Support](mailto:support@usecharming.com)