diff --git a/surfsense_backend/tests/unit/agents/multi_agent_chat/shared/retrieved_context/test_renderer.py b/surfsense_backend/tests/unit/agents/multi_agent_chat/shared/retrieved_context/test_renderer.py
new file mode 100644
index 000000000..c0dee17e8
--- /dev/null
+++ b/surfsense_backend/tests/unit/agents/multi_agent_chat/shared/retrieved_context/test_renderer.py
@@ -0,0 +1,146 @@
+"""Tests for the <retrieved_context> renderer and its citation registration."""
+
+from __future__ import annotations
+
+import pytest
+
+from app.agents.chat.multi_agent_chat.shared.citations import (
+    CitationRegistry,
+    CitationSourceType,
+)
+from app.agents.chat.multi_agent_chat.shared.retrieved_context import (
+    RetrievedDocument,
+    RetrievedPassage,
+    render_retrieved_context,
+)
+
+pytestmark = pytest.mark.unit
+
+
+def _document(
+    document_id: int,
+    title: str,
+    chunk_ids: list[int],
+    *,
+    source_label: str | None = None,
+    is_complete: bool = False,
+) -> RetrievedDocument:
+    return RetrievedDocument(
+        document_id=document_id,
+        title=title,
+        source_label=source_label,
+        is_complete=is_complete,
+        passages=[
+            RetrievedPassage(document_id=document_id, chunk_id=cid, content=f"text {cid}")
+            for cid in chunk_ids
+        ],
+    )
+
+
+def test_returns_none_when_nothing_to_show() -> None:
+    registry = CitationRegistry()
+
+    assert render_retrieved_context([], registry) is None
+    assert render_retrieved_context([_document(1, "Empty", [])], registry) is None
+
+
+def test_assigns_monotonic_labels_across_documents() -> None:
+    registry = CitationRegistry()
+
+    block = render_retrieved_context(
+        [
+            _document(1, "Q3 Launch Notes", [880, 881], source_label="Slack"),
+            _document(2, "Timeline", [12], source_label="Notion"),
+        ],
+        registry,
+    )
+
+    assert block is not None
+    assert "[1] text 880" in block
+    assert "[2] text 881" in block
+    assert "[3] text 12" in block
+
+
+def test_registers_passages_with_chunk_locators() -> None:
+    registry = CitationRegistry()
+
+    render_retrieved_context([_document(1, "Doc", [880])], registry)
+
+    entry = registry.resolve(1)
+    assert entry is not None
+    assert entry.source_type is CitationSourceType.KB_CHUNK
+    assert entry.locator == {"document_id": 1, "chunk_id": 880}
+    assert entry.display["title"] == "Doc"
+
+
+def test_header_shows_source_and_completeness() -> None:
+    registry = CitationRegistry()
+
+    block = render_retrieved_context(
+        [
+            _document(1, "Q3", [1], source_label="Slack · #launch", is_complete=False),
+            _document(2, "Plan", [2], is_complete=True),
+        ],
+        registry,
+    )
+
+    assert block is not None
+    assert 'Document: "Q3"  (Slack · #launch)  (partial)' in block
+    assert 'Document: "Plan"  (complete)' in block
+
+
+def test_wraps_block_and_explains_chunk_vs_document() -> None:
+    registry = CitationRegistry()
+
+    block = render_retrieved_context([_document(1, "Doc", [1])], registry)
+
+    assert block is not None
+    assert block.startswith("<retrieved_context>")
+    assert block.endswith("</retrieved_context>")
+    assert "Cite a chunk with [n]." in block
+
+
+def test_multiline_passage_is_indented_under_label() -> None:
+    registry = CitationRegistry()
+    document = RetrievedDocument(
+        document_id=1,
+        title="Doc",
+        passages=[RetrievedPassage(document_id=1, chunk_id=5, content="line one\nline two")],
+    )
+
+    block = render_retrieved_context([document], registry)
+
+    assert block is not None
+    assert "  [1] line one\n      line two" in block
+
+
+def test_continuation_indent_tracks_label_width() -> None:
+    registry = CitationRegistry()
+    # Burn labels 1..9 so the tenth passage renders as [10] (a 7-char label).
+    documents = [_document(i, f"Doc {i}", [i]) for i in range(1, 10)]
+    documents.append(
+        RetrievedDocument(
+            document_id=10,
+            title="Doc 10",
+            passages=[
+                RetrievedPassage(document_id=10, chunk_id=10, content="line one\nline two")
+            ],
+        )
+    )
+
+    block = render_retrieved_context(documents, registry)
+
+    assert block is not None
+    assert "  [10] line one\n       line two" in block
+
+
+def test_same_passage_reuses_label_across_calls() -> None:
+    registry = CitationRegistry()
+    document = _document(1, "Doc", [880])
+
+    render_retrieved_context([document], registry)
+    block = render_retrieved_context([document], registry)
+
+    assert block is not None
+    assert "[1] text 880" in block
+    assert registry.next_n == 2