feat(ux): improve interactive mode readability and input visibility

- Replace plain 'tai>' prompt with styled console.input() bold cyan prompt
- Wrap interactive mode entry in a Rich Panel with border
- Frame each AI response with Rule dividers (──── AI Response ────)
- Style guardrail warnings with ⚠ prefix and bold yellow
- Improve /help output with formatted Panel showing all commands
- Style collection report: ✓/✗ per item with color, truncation in dim
- Style probe output: ✓/✗ with green/red, host info in dim
- Add Rule header divider on session start

.gitea/workflows/ci.yml

@@ -59,13 +59,9 @@ jobs:
 
       - name: Ensure Python and pip are available
         run: |
-          if command -v python3 >/dev/null 2>&1 && python3 -m pip --version >/dev/null 2>&1; then
-            python3 --version
-            exit 0
-          fi
-
           if command -v apt-get >/dev/null 2>&1; then
             apt-get update
+            apt-get install -y python3.12 python3.12-venv python3-pip || \
               apt-get install -y python3 python3-pip python3-venv
           elif command -v dnf >/dev/null 2>&1; then
             dnf install -y python3 python3-pip
@@ -76,11 +72,11 @@ jobs:
             exit 1
           fi
 
-          python3 --version
+          python3.12 --version || python3 --version
 
       - name: Install package and dev dependencies
         run: |
-          python3 -m venv .venv
+          python3.12 -m venv .venv 2>/dev/null || python3 -m venv .venv
           . .venv/bin/activate
           python -m pip install --upgrade pip
           python -m pip install -e .[dev]

.gitea/workflows/release.yml

@@ -59,32 +59,35 @@ jobs:
 
       - name: Ensure Python and build dependencies are available
         run: |
-          if ! command -v python3 >/dev/null 2>&1; then
           if command -v apt-get >/dev/null 2>&1; then
             apt-get update
+            apt-get install -y python3.12 python3.12-venv python3-pip patchelf ccache || \
               apt-get install -y python3 python3-pip python3-venv patchelf ccache
           elif command -v dnf >/dev/null 2>&1; then
-              dnf install -y python3 python3-pip patchelf ccache
+            dnf install -y python3 python3-pip python3-devel patchelf ccache
-            fi
+          elif command -v yum >/dev/null 2>&1; then
+            yum install -y python3 python3-pip python3-devel patchelf ccache
+          else
+            echo "No supported package manager found to install Python/build deps."
+            exit 1
           fi
 
-          # patchelf is required by Nuitka for standalone Linux binaries
+          python3.12 --version || python3 --version
-          command -v patchelf >/dev/null 2>&1 || {
-            apt-get update && apt-get install -y patchelf
-          }
-
-          python3 --version
 
       - name: Set up venv and install package + build deps
         run: |
-          python3 -m venv .venv
+          python3.12 -m venv .venv 2>/dev/null || python3 -m venv .venv
           . .venv/bin/activate
           python -m pip install --upgrade pip
           python -m pip install -e ".[build]"
 
       - name: Derive version from tag
         id: version
-        run: echo "tag=${GITHUB_REF_NAME}" >> "$GITHUB_OUTPUT"
+        run: |
+          tag="${GITHUB_REF_NAME}"
+          deb_version="${tag#v}"  # Remove leading 'v' if present
+          echo "tag=${tag}" >> "$GITHUB_OUTPUT"
+          echo "deb_version=${deb_version}" >> "$GITHUB_OUTPUT"
 
       - name: Build standalone binary with Nuitka
         run: |
@@ -101,6 +104,33 @@ jobs:
       - name: Smoke-test the binary
         run: dist/tai --help
 
+      - name: Build .deb package
+        run: |
+          pkg_root="pkgroot"
+          pkg_name="tai"
+          deb_version="${{ steps.version.outputs.deb_version }}"
+          arch="amd64"
+          out_dir="dist"
+          deb_dir="${pkg_root}/${pkg_name}_${deb_version}_${arch}"
+
+          rm -rf "${pkg_root}"
+          mkdir -p "${deb_dir}/DEBIAN"
+          mkdir -p "${deb_dir}/usr/bin"
+
+          install -m 0755 dist/tai "${deb_dir}/usr/bin/tai"
+
+          cat > "${deb_dir}/DEBIAN/control" <<EOF
+          Package: ${pkg_name}
+          Version: ${deb_version}
+          Section: admin
+          Priority: optional
+          Architecture: ${arch}
+          Maintainer: tai maintainers <noreply@example.com>
+          Description: tai Linux troubleshooting assistant
+          EOF
+
+          dpkg-deb --build "${deb_dir}" "${out_dir}/${pkg_name}_${deb_version}_${arch}.deb"
+
       - name: Upload binary artifact
         uses: actions/upload-artifact@v3
         with:
@@ -108,3 +138,11 @@ jobs:
           path: dist/tai
           if-no-files-found: error
           retention-days: 90
+
+      - name: Upload deb artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: tai-deb-amd64-${{ steps.version.outputs.tag }}
+          path: dist/tai_${{ steps.version.outputs.deb_version }}_amd64.deb
+          if-no-files-found: error
+          retention-days: 90

.gitignore

@@ -24,3 +24,6 @@ htmlcov/
 
 # IDE
 .vscode/
+
+# Logs and session files
+logs/

src/tai/ai_client.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 from collections.abc import Iterator
 from dataclasses import dataclass, field
+from typing import Any, cast
 
 from openai import OpenAI
 
@@ -88,6 +89,20 @@ class AIClient:
             if delta:
                 yield delta
 
+    def stream_messages(self, messages: list[dict[str, str]]) -> Iterator[str]:
+        """Stream a completion from an explicit chat history."""
+        stream = self._client.chat.completions.create(
+            model=self._config.model,
+            max_tokens=self._config.max_tokens,
+            stream=True,
+            messages=cast(Any, messages),
+        )
+
+        for chunk in cast(Iterator[Any], stream):
+            delta = chunk.choices[0].delta.content
+            if delta:
+                yield delta
+
     def summary(self) -> str:
         """Human-readable description of the AI config."""
         return f"host={self._config.host} model={self._config.model}"

src/tai/ai_guardrails.py

@@ -0,0 +1,36 @@
+"""Heuristic checks for AI response quality and safety."""
+
+from __future__ import annotations
+
+import re
+
+_RISKY_ACTION_PATTERNS = [
+    r"\bsystemctl\s+(restart|stop|start)\b",
+    r"\b(edit|modify|change)\s+/etc/",
+    r"\bpasswd\b",
+    r"\bapt\s+install\b",
+    r"\bdnf\s+install\b",
+    r"\byum\s+install\b",
+]
+
+
+def validate_ai_response(response: str) -> list[str]:
+    """Return warning messages for potentially unsafe or weakly grounded output."""
+    warnings: list[str] = []
+
+    if "Evidence" not in response:
+        warnings.append("Response is missing an Evidence section.")
+
+    if "`" not in response:
+        warnings.append("Response does not include quoted evidence snippets.")
+
+    lower_response = response.lower()
+    for pattern in _RISKY_ACTION_PATTERNS:
+        if re.search(pattern, lower_response):
+            warnings.append(
+                "Response suggests potentially modifying actions; "
+                "prefer read-only verification unless remediation was explicitly requested."
+            )
+            break
+
+    return warnings

src/tai/cli.py

@@ -8,14 +8,19 @@ from typing import Annotated
 import typer
 from rich.console import Console
 from rich.markdown import Markdown
+from rich.panel import Panel
+from rich.rule import Rule
+from rich.text import Text
 
 from tai.ai_client import DEFAULT_AI_HOST, DEFAULT_MODEL, AIClient, AIConfig
+from tai.ai_guardrails import validate_ai_response
 from tai.collectors import CollectionReport, collect_from_plan
 from tai.input_parser import InputValidationError, build_request
 from tai.models import TroubleshootRequest
 from tai.plan import plan_from_request
-from tai.prompt_builder import build_system_prompt, build_user_message
+from tai.prompt_builder import build_followup_message, build_system_prompt, build_user_message
-from tai.ssh_client import SSHClient, SSHCommandResult, SSHConnectionConfig
+from tai.session_log import SessionLogger
+from tai.ssh_client import SSHClient, SSHCommandResult, SSHConnectionConfig, SSHSession
 
 app = typer.Typer(no_args_is_help=True, add_completion=False)
 console = Console()
@@ -66,6 +71,13 @@ def run(
             help="Send collected diagnostics to AI for analysis.",
         ),
     ] = False,
+    interactive: Annotated[
+        bool,
+        typer.Option(
+            "--interactive/--no-interactive",
+            help="Start interactive follow-up mode (/collect, /analyze, /quit).",
+        ),
+    ] = False,
     ai_host: Annotated[
         str,
         typer.Option("--ai-host", help="OpenAI-compatible AI backend URL."),
@@ -78,6 +90,13 @@ def run(
         str,
         typer.Option("--ai-key", help="API key for the AI backend (not needed for Ollama)."),
     ] = "ollama",
+    log_file: Annotated[
+        str | None,
+        typer.Option(
+            "--log-file",
+            help="Optional JSONL file path to log AI and session output.",
+        ),
+    ] = None,
 ) -> None:
     """Start an interactive troubleshooting session scaffold."""
     try:
@@ -103,22 +122,34 @@ def run(
     )
 
     summary = SSHClient(config).summary()
-    console.print("[bold green]tai[/bold green]")
+    console.print(Rule("[bold green]tai[/bold green]", style="green"))
-    console.print(f"Issue: {req.issue}")
+    console.print(f"  [bold]Issue:[/bold] {req.issue}")
-    console.print(f"SSH:   {summary}")
+    console.print(f"  [bold]SSH:[/bold]   {summary}")
     if req.target_paths:
-        console.print(f"Paths: {', '.join(str(p) for p in req.target_paths)}")
+        console.print(f"  [bold]Paths:[/bold] {', '.join(str(p) for p in req.target_paths)}")
+    console.print()
 
-    if not (probe or collect or analyze):
+    if not (probe or collect or analyze or interactive):
         return  # nothing SSH-related requested
 
     ai_config = AIConfig(host=ai_host, model=model, api_key=ai_key)
-    if analyze:
+    logger = SessionLogger.create(log_file) if log_file else None
+    if analyze or interactive:
         console.print(f"[cyan]AI:[/cyan] {AIClient(ai_config).summary()}")
 
     try:
-        asyncio.run(_async_main(config, req, probe=probe, collect=collect, analyze=analyze,
+        asyncio.run(
-                                ai_config=ai_config))
+            _async_main(
+                config,
+                req,
+                probe=probe,
+                collect=collect,
+                analyze=analyze,
+                interactive=interactive,
+                ai_config=ai_config,
+                logger=logger,
+            )
+        )
     except typer.Exit:
         raise
     except TimeoutError as exc:
@@ -136,14 +167,38 @@ async def _async_main(
     probe: bool,
     collect: bool,
     analyze: bool,
+    interactive: bool,
     ai_config: AIConfig,
+    logger: SessionLogger | None,
 ) -> None:
     """Open a single SSH session and run probe / collection / analysis through it."""
     client = SSHClient(config)
+    if logger is not None:
+        logger.log_event(
+            "session_start",
+            {
+                "host": req.host,
+                "port": req.port,
+                "issue": req.issue,
+                "probe": probe,
+                "collect": collect,
+                "analyze": analyze,
+                "interactive": interactive,
+            },
+        )
     async with client.connect() as session:
         if probe:
             result = await session.probe()
             _handle_probe_result(result)
+            if logger is not None:
+                logger.log_event(
+                    "probe_result",
+                    {
+                        "exit_code": result.exit_code,
+                        "stdout": result.stdout,
+                        "stderr": result.stderr,
+                    },
+                )
 
         report: CollectionReport | None = None
         if collect or analyze:
@@ -151,38 +206,177 @@ async def _async_main(
             console.print(f"[cyan]Collecting diagnostics:[/cyan] {len(plan)} commands")
             report = await collect_from_plan(session, plan)
             _handle_collection_report(report)
+            if logger is not None:
+                logger.log_event(
+                    "collection_summary",
+                    {
+                        "total": report.total,
+                        "failed": report.failed,
+                    },
+                )
 
         if analyze and report is not None:
-            _run_analysis(ai_config, req.issue, report)
+            _run_analysis(ai_config, req.issue, report, logger=logger)
+
+        if interactive:
+            await _interactive_loop(session, req, ai_config, report, logger=logger)
+
+
+async def _interactive_loop(
+    session: SSHSession,
+    req: TroubleshootRequest,
+    ai_config: AIConfig,
+    report: CollectionReport | None,
+    logger: SessionLogger | None,
+) -> None:
+    """Run a follow-up loop for collecting and conversational analysis."""
+    console.print(
+        Panel(
+            "Ask questions directly, or use [bold]/collect[/bold], "
+            "[bold]/analyze[/bold], [bold]/help[/bold], [bold]/quit[/bold]",
+            title="[bold cyan]Interactive Mode[/bold cyan]",
+            border_style="cyan",
+            padding=(0, 1),
+        )
+    )
+
+    prior_questions: list[str] = []
+
+    while True:
+        try:
+            command = console.input("\n[bold cyan]tai[/bold cyan][dim] >[/dim] ").strip()
+        except (EOFError, KeyboardInterrupt):
+            console.print("\n[yellow]Exiting interactive mode.[/yellow]")
+            if logger is not None:
+                logger.log_event("interactive_exit", {"reason": "signal_or_eof"})
+            return
+
+        if not command:
+            continue
+
+        if command in {"/quit", "/exit"}:
+            console.print("[green]Bye.[/green]")
+            if logger is not None:
+                logger.log_event("interactive_exit", {"reason": "user_quit"})
+            return
+
+        if command == "/help":
+            console.print(
+                Panel(
+                    "[bold]/collect[/bold]  — re-run diagnostics\n"
+                    "[bold]/analyze[/bold]  — re-analyze current diagnostics\n"
+                    "[bold]/help[/bold]     — show this message\n"
+                    "[bold]/quit[/bold]     — end session\n"
+                    "[dim]Anything else is sent directly to the AI as a question.[/dim]",
+                    title="[bold]Commands[/bold]",
+                    border_style="dim",
+                    padding=(0, 1),
+                )
+            )
+            continue
+
+        if command == "/collect":
+            plan = plan_from_request(req)
+            console.print(f"[cyan]Collecting diagnostics:[/cyan] {len(plan)} commands")
+            report = await collect_from_plan(session, plan)
+            _handle_collection_report(report)
+            if logger is not None:
+                logger.log_event(
+                    "collection_summary",
+                    {
+                        "total": report.total,
+                        "failed": report.failed,
+                    },
+                )
+            continue
+
+        if command == "/analyze":
+            if report is None:
+                plan = plan_from_request(req)
+                console.print(f"[cyan]Collecting diagnostics:[/cyan] {len(plan)} commands")
+                report = await collect_from_plan(session, plan)
+                _handle_collection_report(report)
+            if report is None:
+                console.print("[red]No diagnostics available to analyze.[/red]")
+                continue
+
+            _run_followup_analysis(
+                ai_config,
+                req.issue,
+                report,
+                "Provide an updated diagnosis from the current diagnostics.",
+                prior_questions,
+                logger=logger,
+            )
+            prior_questions.append("/analyze")
+            if logger is not None:
+                logger.log_event("interactive_followup", {"question": "/analyze"})
+            continue
+
+        if report is None:
+            plan = plan_from_request(req)
+            console.print(f"[cyan]Collecting diagnostics:[/cyan] {len(plan)} commands")
+            report = await collect_from_plan(session, plan)
+            _handle_collection_report(report)
+
+        if report is None:
+            console.print("[red]No diagnostics available to analyze.[/red]")
+            continue
+
+        _run_followup_analysis(
+            ai_config,
+            req.issue,
+            report,
+            command,
+            prior_questions,
+            logger=logger,
+        )
+        prior_questions.append(command)
+        if logger is not None:
+            logger.log_event("interactive_followup", {"question": command})
 
 
 def _handle_probe_result(result: SSHCommandResult) -> None:
     """Handle and render probe output for success or failure."""
-    console.print("[cyan]Running SSH probe:[/cyan] uname -a")
+    console.print("[dim]▶ SSH probe:[/dim] uname -a")
     if result.exit_code != 0:
         details = result.stderr or result.stdout or "no error output from ssh"
-        console.print(f"[red]Probe failed (exit {result.exit_code}):[/red] {details}")
+        console.print(f"[bold red]✗ Probe failed[/bold red] (exit {result.exit_code}): {details}")
         raise typer.Exit(code=1)
     output = result.stdout or "(no output)"
-    console.print("[bold green]Probe succeeded.[/bold green]")
+    console.print("[bold green]✓ Probe succeeded.[/bold green]")
-    console.print(f"Remote: {output}")
+    console.print(f"  [dim]{output}[/dim]")
 
 
 def _handle_collection_report(report: CollectionReport) -> None:
     """Render collected command status and truncation hints."""
-    console.print(
+    failed_label = (
-        f"[bold]Collection complete:[/bold] {report.total} commands, {report.failed} failed"
+        f"[red]{report.failed} failed[/red]" if report.failed else "[green]0 failed[/green]"
     )
+    console.print(f"[bold]Collection complete:[/bold] {report.total} commands, {failed_label}")
     for item in report.items:
-        status = "ok" if item.result.exit_code == 0 else f"exit {item.result.exit_code}"
         truncated = item.result.stdout_truncated or item.result.stderr_truncated
-        trunc = " (truncated)" if truncated else ""
+        trunc_label = " [dim](truncated)[/dim]" if truncated else ""
-        console.print(f"- {item.name}: {status}{trunc}")
+        if item.result.exit_code == 0:
+            console.print(f"  [green]✓[/green] [dim]{item.name}[/dim]{trunc_label}")
+        else:
+            console.print(
+                f"  [red]✗[/red] {item.name} "
+                f"[red](exit {item.result.exit_code})[/red]{trunc_label}"
+            )
 
 
-def _run_analysis(ai_config: AIConfig, issue: str, report: CollectionReport) -> None:
+def _run_analysis(
+    ai_config: AIConfig,
+    issue: str,
+    report: CollectionReport,
+    *,
+    logger: SessionLogger | None,
+) -> None:
     """Send collected data to the AI and stream the analysis to stdout."""
-    console.print("[cyan]Analyzing...[/cyan]\n")
+    console.print()
+    console.print(Rule("[bold cyan]Analysis[/bold cyan]", style="cyan"))
+    console.print()
     ai = AIClient(ai_config)
     system_prompt = build_system_prompt()
     user_message = build_user_message(issue, report)
@@ -190,9 +384,78 @@ def _run_analysis(ai_config: AIConfig, issue: str, report: CollectionReport) ->
         chunks: list[str] = []
         for chunk in ai.stream(system_prompt, user_message):
             chunks.append(chunk)
-        console.print(Markdown("".join(chunks)))
+        response = "".join(chunks)
+        console.print(Markdown(response))
+
+        warnings = validate_ai_response(response)
+        for item in warnings:
+            warn_text = Text()
+            warn_text.append("⚠ Guardrail: ", style="bold yellow")
+            warn_text.append(item, style="yellow")
+            console.print(warn_text)
+
+        if logger is not None:
+            logger.log_event(
+                "analysis_response",
+                {
+                    "issue": issue,
+                    "response": response,
+                    "guardrail_warnings": warnings,
+                },
+            )
     except Exception as exc:  # noqa: BLE001
         console.print(f"[red]AI analysis failed:[/red] {exc}")
+        if logger is not None:
+            logger.log_event("analysis_error", {"error": str(exc)})
+        raise typer.Exit(code=1) from exc
+
+
+def _run_followup_analysis(
+    ai_config: AIConfig,
+    issue: str,
+    report: CollectionReport,
+    question: str,
+    prior_questions: list[str],
+    *,
+    logger: SessionLogger | None,
+) -> str:
+    """Run grounded follow-up analysis re-anchored to current diagnostics."""
+    console.print()
+    console.print(Rule("[bold cyan]AI Response[/bold cyan]", style="cyan"))
+    console.print()
+    ai = AIClient(ai_config)
+    system_prompt = build_system_prompt()
+    user_message = build_followup_message(issue, report, question, prior_questions)
+
+    try:
+        chunks: list[str] = []
+        for chunk in ai.stream(system_prompt, user_message):
+            chunks.append(chunk)
+        response = "".join(chunks)
+        console.print(Markdown(response))
+        console.print(Rule(style="dim"))
+
+        warnings = validate_ai_response(response)
+        for item in warnings:
+            warn_text = Text()
+            warn_text.append("⚠ Guardrail: ", style="bold yellow")
+            warn_text.append(item, style="yellow")
+            console.print(warn_text)
+
+        if logger is not None:
+            logger.log_event(
+                "analysis_response",
+                {
+                    "last_user_message": question,
+                    "response": response,
+                    "guardrail_warnings": warnings,
+                },
+            )
+        return response
+    except Exception as exc:  # noqa: BLE001
+        console.print(f"[red]AI analysis failed:[/red] {exc}")
+        if logger is not None:
+            logger.log_event("analysis_error", {"error": str(exc), "question": question})
         raise typer.Exit(code=1) from exc
 
 

src/tai/prompt_builder.py

@@ -15,12 +15,15 @@ Your job:
 
 Important rules:
 - Only draw conclusions from data that is actually present. Do not speculate or invent evidence.
+- For every root-cause claim, quote at least one exact snippet from collected output in backticks.
 - If a command shows "could not be executed (SSH error)" it means the remote host blocked or
   rejected that specific command — it is not evidence about the service or system state.
 - If there is not enough data to diagnose the issue, say so plainly and list exactly what
   additional commands or log files would be needed.
 - Keep the response short. Skip sections that have nothing useful to say.
 - Never suggest commands that modify the system unless explicitly asked.
+- Default to read-only verification steps. Do not suggest restarting services or editing configs
+    unless the user explicitly asks for remediation actions.
 - Format with clear sections: **Root Cause**, **Evidence**, **Recommended Actions**.
 """
 
@@ -72,3 +75,27 @@ def build_user_message(issue: str, report: CollectionReport) -> str:
         )
 
     return "\n".join(lines)
+
+
+def build_followup_message(
+    issue: str,
+    report: CollectionReport,
+    question: str,
+    prior_questions: list[str],
+) -> str:
+    """Build a grounded follow-up message that re-anchors to diagnostics each turn."""
+    base = build_user_message(issue, report)
+    lines: list[str] = [base, "## Follow-up"]
+
+    if prior_questions:
+        lines.append("\nRecent user follow-up questions:")
+        for idx, item in enumerate(prior_questions[-5:], start=1):
+            lines.append(f"{idx}. {item}")
+
+    lines.append("\nCurrent follow-up question:")
+    lines.append(question)
+    lines.append(
+        "\nAnswer strictly from the collected diagnostics above. "
+        "If evidence is insufficient, explicitly say so."
+    )
+    return "\n".join(lines)

src/tai/session_log.py

@@ -0,0 +1,34 @@
+"""Structured session logging helpers for troubleshooting runs."""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from pathlib import Path
+from typing import Any
+
+
+@dataclass(slots=True)
+class SessionLogger:
+    """Append JSONL events to a log file for post-run analysis."""
+
+    path: Path
+
+    @classmethod
+    def create(cls, file_path: str) -> SessionLogger:
+        """Create a logger for *file_path*, ensuring parent directories exist."""
+        path = Path(file_path).expanduser()
+        path.parent.mkdir(parents=True, exist_ok=True)
+        return cls(path=path)
+
+    def log_event(self, event: str, payload: dict[str, Any]) -> None:
+        """Write one timestamped event row to the JSONL log."""
+        row = {
+            "ts": datetime.now(UTC).isoformat(),
+            "event": event,
+            "payload": payload,
+        }
+        with self.path.open("a", encoding="utf-8") as handle:
+            handle.write(json.dumps(row, ensure_ascii=True))
+            handle.write("\n")

tests/test_ai.py

@@ -4,7 +4,7 @@ from unittest.mock import MagicMock, patch
 
 from tai.ai_client import DEFAULT_AI_HOST, DEFAULT_MODEL, AIClient, AIConfig
 from tai.collectors import CollectedItem, CollectionReport
-from tai.prompt_builder import build_system_prompt, build_user_message
+from tai.prompt_builder import build_followup_message, build_system_prompt, build_user_message
 from tai.ssh_client import SSHCommandResult
 
 # ---------------------------------------------------------------------------
@@ -116,6 +116,34 @@ def test_stream_yields_chunks() -> None:
     assert result == ["Root ", "cause ", "found."]
 
 
+def test_stream_messages_yields_chunks() -> None:
+    config = AIConfig()
+    client = AIClient(config)
+
+    def _make_chunk(text: str | None) -> MagicMock:
+        delta = MagicMock()
+        delta.content = text
+        choice = MagicMock()
+        choice.delta = delta
+        chunk = MagicMock()
+        chunk.choices = [choice]
+        return chunk
+
+    mock_chunks = [_make_chunk("A"), _make_chunk(None), _make_chunk("B")]
+
+    with patch.object(client._client.chat.completions, "create", return_value=iter(mock_chunks)):
+        result = list(
+            client.stream_messages(
+                [
+                    {"role": "system", "content": "sys"},
+                    {"role": "user", "content": "question"},
+                ]
+            )
+        )
+
+    assert result == ["A", "B"]
+
+
 # ---------------------------------------------------------------------------
 # prompt_builder
 # ---------------------------------------------------------------------------
@@ -190,3 +218,16 @@ def test_build_user_message_handles_no_output() -> None:
     report = _make_report([("empty", "cat /nonexistent", 1, "", "")])
     msg = build_user_message("test", report)
     assert "no output" in msg
+
+
+def test_build_followup_message_includes_question_context() -> None:
+    report = _make_report([("kernel", "uname -a", 0, "Linux web01", "")])
+    msg = build_followup_message(
+        "nginx is failing",
+        report,
+        "what should I check next?",
+        ["is nginx running?", "show me logs"],
+    )
+    assert "Current follow-up question" in msg
+    assert "what should I check next?" in msg
+    assert "Recent user follow-up questions" in msg

tests/test_ai_guardrails.py

@@ -0,0 +1,24 @@
+"""Tests for AI response guardrails."""
+
+from tai.ai_guardrails import validate_ai_response
+
+
+def test_validate_ai_response_flags_missing_evidence_and_quotes() -> None:
+    warnings = validate_ai_response("Root cause only, no structure.")
+    assert any("Evidence section" in item for item in warnings)
+    assert any("quoted evidence" in item for item in warnings)
+
+
+def test_validate_ai_response_flags_risky_actions() -> None:
+    text = "Evidence: `PasswordAuthentication no`\nRun systemctl restart sshd now."
+    warnings = validate_ai_response(text)
+    assert any("modifying actions" in item for item in warnings)
+
+
+def test_validate_ai_response_allows_grounded_read_only_answer() -> None:
+    text = (
+        "Evidence: `PasswordAuthentication no`\n"
+        "Recommended Actions: run `journalctl -u sshd -n 200 --no-pager`"
+    )
+    warnings = validate_ai_response(text)
+    assert not warnings

tests/test_cli.py

@@ -137,5 +137,96 @@ def test_collect_success_prints_summary(monkeypatch) -> None:  # type: ignore[no
 
     assert result.exit_code == 0
     assert "Collection complete" in result.stdout
-    assert "kernel: ok" in result.stdout
+    assert "kernel" in result.stdout
-    assert "journal: ok (truncated)" in result.stdout
+    assert "journal" in result.stdout
+    assert "truncated" in result.stdout
+
+
+def test_interactive_collect_then_quit(monkeypatch) -> None:  # type: ignore[no-untyped-def]
+    _mock_session(monkeypatch)
+
+    async def fake_collect_from_plan(_session, _plan) -> CollectionReport:  # type: ignore[no-untyped-def]
+        return CollectionReport(
+            host="ssh.archflux.net",
+            items=[
+                CollectedItem(
+                    name="kernel",
+                    result=SSHCommandResult(
+                        command="uname -a",
+                        exit_code=0,
+                        stdout="Linux test",
+                        stderr="",
+                    ),
+                ),
+            ],
+        )
+
+    commands = iter(["/collect", "/quit"])
+
+    monkeypatch.setattr("tai.cli.collect_from_plan", fake_collect_from_plan)
+    monkeypatch.setattr("tai.cli.console.input", lambda _prompt: next(commands))
+
+    runner = CliRunner()
+    result = runner.invoke(
+        app,
+        [
+            "apache failed",
+            "--host",
+            "ssh.archflux.net",
+            "--port",
+            "5566",
+            "--no-probe",
+            "--interactive",
+        ],
+    )
+
+    assert result.exit_code == 0
+    assert "ask questions directly" in result.stdout.lower()
+    assert "Collection complete" in result.stdout
+    assert "Bye." in result.stdout
+
+
+def test_interactive_unknown_command_prints_hint(monkeypatch) -> None:  # type: ignore[no-untyped-def]
+    _mock_session(monkeypatch)
+
+    async def fake_collect_from_plan(_session, _plan) -> CollectionReport:  # type: ignore[no-untyped-def]
+        return CollectionReport(
+            host="ssh.archflux.net",
+            items=[
+                CollectedItem(
+                    name="kernel",
+                    result=SSHCommandResult(
+                        command="uname -a",
+                        exit_code=0,
+                        stdout="Linux test",
+                        stderr="",
+                    ),
+                ),
+            ],
+        )
+
+    commands = iter(["what should I check next?", "/quit"])
+    monkeypatch.setattr("tai.cli.collect_from_plan", fake_collect_from_plan)
+    monkeypatch.setattr(
+        "tai.cli.AIClient.stream",
+        lambda *_args, **_kwargs: iter(["Check logs."]),
+    )
+    monkeypatch.setattr("tai.cli.console.input", lambda _prompt: next(commands))
+
+    runner = CliRunner()
+    result = runner.invoke(
+        app,
+        [
+            "apache failed",
+            "--host",
+            "ssh.archflux.net",
+            "--port",
+            "5566",
+            "--no-probe",
+            "--interactive",
+        ],
+    )
+
+    assert result.exit_code == 0
+    assert "AI Response" in result.stdout
+    assert "Check logs." in result.stdout

tests/test_session_log.py

@@ -0,0 +1,22 @@
+"""Tests for structured session logging."""
+
+from __future__ import annotations
+
+import json
+
+from tai.session_log import SessionLogger
+
+
+def test_session_logger_writes_jsonl_row(tmp_path) -> None:  # type: ignore[no-untyped-def]
+    log_path = tmp_path / "logs" / "session.jsonl"
+    logger = SessionLogger.create(str(log_path))
+
+    logger.log_event("analysis_response", {"response": "Root cause is X"})
+
+    lines = log_path.read_text(encoding="utf-8").splitlines()
+    assert len(lines) == 1
+
+    row = json.loads(lines[0])
+    assert row["event"] == "analysis_response"
+    assert row["payload"]["response"] == "Root cause is X"
+    assert "ts" in row