diff --git a/codex_telegram_bridge/pyproject.toml b/codex_telegram_bridge/pyproject.toml
index d56463c..062e1dd 100644
--- a/codex_telegram_bridge/pyproject.toml
+++ b/codex_telegram_bridge/pyproject.toml
@@ -6,6 +6,7 @@ readme = "readme.md"
 requires-python = ">=3.12"
 dependencies = [
   "markdown-it-py",
+  "pytest",
   "sulguk",
   "typer",
 ]
diff --git a/codex_telegram_bridge/tests/conftest.py b/codex_telegram_bridge/tests/conftest.py
new file mode 100644
index 0000000..25412bc
--- /dev/null
+++ b/codex_telegram_bridge/tests/conftest.py
@@ -0,0 +1,5 @@
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))
+
diff --git a/codex_telegram_bridge/tests/test_exec_render.py b/codex_telegram_bridge/tests/test_exec_render.py
new file mode 100644
index 0000000..6af42a4
--- /dev/null
+++ b/codex_telegram_bridge/tests/test_exec_render.py
@@ -0,0 +1,53 @@
+import json
+
+from codex_telegram_bridge.exec_render import ExecProgressRenderer, ExecRenderState, render_event_cli
+
+
+def _loads(lines: str) -> list[dict]:
+    return [json.loads(line) for line in lines.strip().splitlines() if line.strip()]
+
+
+SAMPLE_STREAM = """
+{"type":"thread.started","thread_id":"0199a213-81c0-7800-8aa1-bbab2a035a53"}
+{"type":"turn.started"}
+{"type":"item.completed","item":{"id":"item_0","type":"reasoning","text":"**Searching for README files**"}}
+{"type":"item.started","item":{"id":"item_1","type":"command_execution","command":"bash -lc ls","aggregated_output":"","status":"in_progress"}}
+{"type":"item.completed","item":{"id":"item_1","type":"command_execution","command":"bash -lc ls","aggregated_output":"2025-09-11\\nAGENTS.md\\nCHANGELOG.md\\ncliff.toml\\ncodex-cli\\ncodex-rs\\ndocs\\nexamples\\nflake.lock\\nflake.nix\\nLICENSE\\nnode_modules\\nNOTICE\\npackage.json\\npnpm-lock.yaml\\npnpm-workspace.yaml\\nPNPM.md\\nREADME.md\\nscripts\\nsdk\\ntmp\\n","exit_code":0,"status":"completed"}}
+{"type":"item.completed","item":{"id":"item_2","type":"reasoning","text":"**Checking repository root for README**"}}
+{"type":"item.completed","item":{"id":"item_3","type":"agent_message","text":"Yep — there’s a `README.md` in the repository root."}}
+{"type":"turn.completed","usage":{"input_tokens":24763,"cached_input_tokens":24448,"output_tokens":122}}
+"""
+
+
+def test_render_event_cli_sample_stream() -> None:
+    state = ExecRenderState()
+    out: list[str] = []
+    for evt in _loads(SAMPLE_STREAM):
+        out.extend(render_event_cli(evt, state))
+
+    assert out == [
+        "thread started",
+        "turn started",
+        "[1] ▸ running: `bash -lc ls`",
+        "[1] ✓ ran: `bash -lc ls` (exit 0)",
+        "assistant:",
+        "  Yep — there’s a `README.md` in the repository root.",
+        "turn completed",
+    ]
+
+
+def test_progress_renderer_renders_progress_and_final() -> None:
+    r = ExecProgressRenderer(max_actions=5, max_chars=10_000)
+    for evt in _loads(SAMPLE_STREAM):
+        r.note_event(evt)
+
+    progress = r.render_progress(3.0)
+    assert progress.startswith("working · 3s · turn 3")
+    assert "[1] ✓ ran: `bash -lc ls` (exit 0)" in progress
+
+    final = r.render_final(3.0, "answer", status="done")
+    assert final.startswith("done · 3s · turn 3")
+    assert "running:" not in final
+    assert "ran:" not in final
+    assert final.endswith("answer")
+