Build your own Skype.

# Build an original app inspired by Skype

You are an experienced product designer and full-stack engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: Web. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original contact-based messenger called Callbridge, inspired by the historical Skype workflow. Skype retired in May 2025; use it as a reference for contacts, conversations, and one-to-one internet calls, not an integration target. The primary journey is accepting a contact, exchanging a message, starting a video call, and hanging up cleanly.

## Design
Use an original desktop-friendly browser layout with a contact list, conversation panel, and clear incoming-call overlay. Show real online/connection state, ringing, declined, busy, ended, and failed states. Camera and microphone controls must clearly indicate whether media is active.

## Features
1. Contacts: authenticate users, search by handle, request/approve contacts, remove or block a contact, and show presence with a timeout. A stale connection must not imply the person is online forever.

2. Messaging: send and receive private text messages, paginate history, edit/delete your own messages, and keep unread positions per conversation. Use client-generated message IDs for safe reconnect retries.

3. Calling: establish one-to-one WebRTC audio/video through authenticated signaling, use configured STUN/TURN infrastructure, and support incoming-call accept/decline, busy state, and timeout. Handle simultaneous call attempts consistently.

4. Device controls: request microphone/camera permission on user intent, preview devices, mute/unmute, stop/restart camera, and switch supported inputs. Permission failure must leave text chat available.

5. Session cleanup: end a call from either side, detect disconnect/reconnect, close peer connections, stop all media tracks, and record minimal call metadata. No call recording or hidden background microphone access.

## Tech stack
Use a TypeScript client/API, PostgreSQL for contacts/messages, WebSockets for signaling, and browser WebRTC for media. Authenticate signaling events and bind them to permitted call participants. A reachable TURN service is necessary for reliable internet calls; provide configuration and an honest limitation when it is unavailable.

## Data & behavior
User; ContactRequest; ContactRelationship; Block; Conversation; Participant; Message {clientId, authorId, body}; ReadPosition; CallSession {callerId, calleeId, state, expiresAt}; SignalingSession. Store call state, not captured media. Bound ephemeral presence and enforce contact/block rules before signaling.

Acceptance checks and scope:
Test two-user text and video, denied microphone permission, recipient decline/busy, simultaneous calls, TURN-only connectivity when configured, dropped signaling, and hanging up from either end. Exclude phone-number calling, Skype account migration, group conferences, and recordings.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.