feat(prompts): add course content reproduction policy and related tests

app/prompts.py

@@ -158,6 +158,44 @@ ANSWERING_RULES = """## Answering rules
 
 The retrieval tool returns JSON with matched passages and source metadata."""
 
+CORPUS_REPRODUCTION_POLICY = """## Course content reproduction policy
+
+The knowledge base mixes two kinds of material with different reproduction rules,
+whether you obtained the text from `retrieve_tutor_context` or by browsing files
+with `run_kb_command`:
+
+- COURSE material: the paid Towards AI Academy courses. In the KB these live
+  under `raw/courses/` (wiki pages under `wiki/courses/`), and retrieval results
+  whose source is a course source. This is proprietary, paid content.
+- LIBRARY / DOCUMENTATION material: public open-source documentation, e.g.
+  Transformers, PEFT, TRL, LlamaIndex, LangChain, LangGraph, Deep Agents, OpenAI,
+  and Claude Code. In the KB these live under `raw/docs/`. This is public.
+
+Rules:
+
+- For COURSE material, teach fully: explain concepts in your own words, work
+  through examples, and quote SHORT excerpts (at most a few sentences, or a
+  single short code snippet) when a direct quote genuinely helps. Do NOT
+  reproduce a whole lesson, a whole section, or any large continuous span
+  verbatim, and do NOT stitch quotes together so the reply reconstructs most of
+  a lesson. If the student asks you to print, paste, dump, or otherwise output a
+  full lesson or course page verbatim or "in its entirety", decline that
+  specific request and instead give a teaching summary with a few short
+  illustrative quotes, then point them to the course. Teaching the content is
+  encouraged; redistributing it wholesale is not.
+- If a student says they cannot afford the course, or raises price as the reason
+  they want the full text, still decline to hand over the lesson and still teach
+  them, but let them know they can email louis@towardsai.net to ask about
+  discounts or affordability options. Mention this ONLY when the student
+  themselves brings up cost or affordability; never offer it unprompted, and
+  never promise a specific discount.
+- For LIBRARY / DOCUMENTATION material, verbatim reproduction is fine: you may
+  quote documentation, API references, and code examples in full when that best
+  answers the question.
+
+This restriction is only about wholesale copying of paid course text. It never
+limits how much you help: always give a complete, useful answer."""
+
 NO_KB_NOTE = """## Knowledge base disabled
 
 The user deselected every knowledge-base source for this conversation, so the
@@ -293,4 +331,5 @@ def build_system_prompt(
             )
     parts.append(RETRIEVAL_CALL_STRATEGY)
     parts.append(ANSWERING_RULES)
+    parts.append(CORPUS_REPRODUCTION_POLICY)
     return "\n\n".join(parts) + "\n"

tests/test_prompts.py

@@ -79,6 +79,33 @@ def test_build_system_prompt_without_local_tools_describes_none_of_them(
     assert "one tool available" not in no_tools
 
 
+def test_build_system_prompt_includes_course_reproduction_policy() -> None:
+    # The policy must reach the model whenever it can touch the corpus: both the
+    # full KB-browsing path and the retrieval-only path (disable_kb).
+    kb_on = build_system_prompt(
+        "google-genai:gemini-3.5-flash", (), kb_agents_instructions=""
+    )
+    retrieval_only = build_system_prompt(
+        "google-genai:gemini-3.5-flash", (), disable_kb=True
+    )
+    for prompt in (kb_on, retrieval_only):
+        assert "## Course content reproduction policy" in prompt
+        assert "raw/courses/" in prompt
+        assert "raw/docs/" in prompt
+        # Affordability redirect, gated on the student raising cost.
+        assert "louis@towardsai.net" in prompt
+        assert "never offer it unprompted" in prompt
+
+
+def test_course_reproduction_policy_absent_without_corpus_access() -> None:
+    # No sources selected: the agent has no corpus to copy from, so the policy
+    # (which only governs corpus text) must not appear.
+    prompt = build_system_prompt(
+        "google-genai:gemini-3.5-flash", (), include_local_tools=False
+    )
+    assert "## Course content reproduction policy" not in prompt
+
+
 def test_build_system_prompt_uses_explicit_instructions_without_file_read(
     tmp_path: Path,
     monkeypatch,