Stream fidelity and sessions

Prepare backend, clients and state

Prerequisites: Demo130, Demo400 and Demo410. Working files: Demo410/Backend, Client, Console, Web and Wpf; tests/Streaming.Tests. Copy the full distribution. Tests use a scripted model client; interactive manipulation requires real chat and the precompiled MCP server. WPF requires Windows and uses MVVM Toolkit.

• Demo410 — Streaming Interfaces

Resume without confusing display and memory

Follow Demo410 backend/client commands in separate terminals. Use an isolated state directory and retain its path. Send BLUE-731 in a successful turn, clear only the display, then ask for the marker with the same ID. Repeat with a new ID. Restart the backend with the same directory and reuse the original ID.

dotnet test tests/Streaming.Tests/Streaming.Tests.csproj -m:1 -c Release --no-build --no-restore

Observe bytes and terminal state

Controlled cases preserve spaces, tabs, line breaks and Unicode even when an NDJSON line spans reads. Only completed confirms generation and saving. EOF without a terminal remains truncated. Canceling before commit retains the last successful snapshot; losing the connection after commit can leave completion unconfirmed. Model prose does not prove isolation: inspect assertions and session files.

Separate four boundaries

HTTP packet, network read, NDJSON frame and token are different boundaries. Compare reconstructed text with known test fragments, not a model paraphrase. Check incremental UTF-8 decoding and a partial line at EOF. A 409 signals the global generation gate with no hidden queue.

Correction with visible stream evidence

• Streaming and interfaces

• Session history and persistence

The correction uses Streaming.Tests: exact character preservation, explicit termination, cancellation before commit and concurrent-request rejection. Separate test results, interactive observation and business conclusions in your report. Do not automatically retry a request whose acknowledgement was lost.

Interface reservations

A session ID is not authentication. Clearing client history does not delete all snapshots. Graphical WPF acceptance and model recall quality remain separate from protocol tests. No exactly-once HTTP-turn guarantee is promised.

Complete the comparison

• Correct and forget a fact

• Exercise index