Chat Application Software Requirements Example

This specification was generated by PostIdea from a plain English description of a real-time chat application. The conversation took under 6 minutes — target users, concurrency expectations, message persistence requirements, and presence tracking needs. What follows is the complete functional and non-functional requirements breakdown: machine-verifiable, implementation-ready, and structured so your AI coding tool can act on it directly.

If you're looking for chat application software requirements that go beyond "users can send messages" and actually tell you what "done" looks like in code, this is it.


Project: Real-Time Chat Application

Version: 1
Generated by: PostIdea pipeline — Socratic discovery → constraint extraction → spec generation


Functional Requirements

FR-01: Users can send and receive messages in real-time

Acceptance Criteria:

Testable Signals: MessageService, send_message, WebSocketHandler


FR-02: Users can create and join chat rooms

Acceptance Criteria:

Testable Signals: RoomService, create_room, join_room


FR-03: Users can see who is currently online in a room

Acceptance Criteria:

Testable Signals: PresenceService, get_online_users


FR-04: Users can view message history for a room

Acceptance Criteria:

Testable Signals: MessageRepository, get_room_messages


FR-05: Users receive notifications for new messages

Acceptance Criteria:

Testable Signals: NotificationService, broadcast_message


FR-06: Users can search message history by keyword

Acceptance Criteria:

Testable Signals: MessageSearchService, search_messages


Non-Functional Requirements

NFR-01: Message delivery latency

NFR-02: Concurrent user support

NFR-03: Message persistence

NFR-04: Secure data transmission


What makes this spec verifiable

Every functional requirement above has two things most chat specs don't: a concrete acceptance criterion written in Given/When/Then format with actual HTTP status codes, WebSocket event structures, and field names, and a testable signal — a specific identifier (class name, function name) that must appear in your source code for the requirement to be considered implemented.

That's what PostIdea's verification engine checks. Not whether your code "looks right." Whether the identifiers the spec requires are actually present in your implementation.

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