diff --git a/pyproject.toml b/pyproject.toml
index e1eaed6..266be47 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,6 +32,7 @@ build-backend = "uv_build"
 
 [dependency-groups]
 dev = [
+    "black>=24.0.0",
     "pytest>=9.0.2",
     "pytest-httpx>=0.35.0",
     "syrupy>=5.0.0",
diff --git a/src/claude_code_transcripts/__init__.py b/src/claude_code_transcripts/__init__.py
index 862a5e0..49a8081 100644
--- a/src/claude_code_transcripts/__init__.py
+++ b/src/claude_code_transcripts/__init__.py
@@ -9,7 +9,7 @@
 import subprocess
 import tempfile
 import webbrowser
-from datetime import datetime
+from datetime import datetime, timezone
 from pathlib import Path
 
 import click
@@ -556,9 +556,207 @@ def parse_session_file(filepath):
     if filepath.suffix == ".jsonl":
         return _parse_jsonl_file(filepath)
     else:
-        # Standard JSON format
         with open(filepath, "r", encoding="utf-8") as f:
-            return json.load(f)
+            data = json.load(f)
+
+        # If already in normalized format, return as-is
+        if isinstance(data, dict) and isinstance(data.get("loglines"), list):
+            return data
+
+        # Attempt to parse Augment ("Augument") chat exports into normalized loglines
+        augment_parsed = _parse_augment_export_data(data)
+        if augment_parsed is not None:
+            return augment_parsed
+
+        # Fallback: return raw JSON (may not be compatible with HTML generation)
+        return data
+
+
+def _coerce_timestamp_to_iso_z(value):
+    """Best-effort conversion of common timestamp shapes to an ISO 8601 string ending in 'Z'."""
+    if value is None:
+        return None
+
+    if isinstance(value, str):
+        v = value.strip()
+        return v or None
+
+    if isinstance(value, (int, float)):
+        # Heuristic: treat very large values as milliseconds since epoch
+        seconds = float(value) / 1000.0 if value > 10_000_000_000 else float(value)
+        try:
+            return (
+                datetime.fromtimestamp(seconds, tz=timezone.utc).isoformat(
+                    timespec="seconds"
+                )
+                + "Z"
+            )
+        except (OverflowError, OSError, ValueError):
+            return None
+
+    if isinstance(value, dict):
+        # Common shapes: {"seconds": ...}, {"ms": ...}, {"epoch_ms": ...}
+        for k in ("timestamp", "time", "created_at", "createdAt", "date"):
+            if k in value:
+                coerced = _coerce_timestamp_to_iso_z(value.get(k))
+                if coerced:
+                    return coerced
+        if "seconds" in value:
+            return _coerce_timestamp_to_iso_z(value.get("seconds"))
+        if "ms" in value:
+            return _coerce_timestamp_to_iso_z(value.get("ms"))
+        if "epoch_ms" in value:
+            return _coerce_timestamp_to_iso_z(value.get("epoch_ms"))
+
+    return None
+
+
+def _normalize_role_to_user_or_assistant(value):
+    if value is None:
+        return None
+
+    if isinstance(value, dict):
+        for k in ("role", "type", "name", "sender"):
+            if k in value:
+                value = value.get(k)
+                break
+
+    if not isinstance(value, str):
+        return None
+
+    role = value.strip().lower()
+    if role in ("user", "human", "me", "client", "customer"):
+        return "user"
+    if role in ("assistant", "ai", "bot", "augment", "agent"):
+        return "assistant"
+    if role in ("u", "usr"):
+        return "user"
+    if role in ("a", "asst"):
+        return "assistant"
+    if role in ("system", "tool", "function"):
+        return None
+    return None
+
+
+def _extract_text_from_maybe_rich_content(value):
+    """Extract a text string from common export shapes."""
+    if value is None:
+        return ""
+    if isinstance(value, str):
+        return value
+    if isinstance(value, dict):
+        for k in ("text", "content", "message", "value", "body"):
+            if k in value:
+                return _extract_text_from_maybe_rich_content(value.get(k))
+        return json.dumps(value, ensure_ascii=False)
+    if isinstance(value, list):
+        parts = []
+        for item in value:
+            t = _extract_text_from_maybe_rich_content(item)
+            if t:
+                parts.append(t)
+        return "\n".join(parts)
+    return str(value)
+
+
+def _iter_augment_message_dicts(data):
+    """Yield message dicts from common Augment export shapes."""
+    if isinstance(data, list):
+        for item in data:
+            if isinstance(item, dict):
+                yield item
+        return
+
+    if not isinstance(data, dict):
+        return
+
+    # Some exports wrap the payload in a "data" field
+    if isinstance(data.get("data"), (dict, list)):
+        yield from _iter_augment_message_dicts(data["data"])
+
+    # Top-level messages list
+    if isinstance(data.get("messages"), list):
+        for m in data["messages"]:
+            if isinstance(m, dict):
+                yield m
+
+    # Single conversation wrapper
+    conv = data.get("conversation")
+    if isinstance(conv, dict) and isinstance(conv.get("messages"), list):
+        for m in conv["messages"]:
+            if isinstance(m, dict):
+                yield m
+
+    # Multiple conversations/chats
+    for key in ("conversations", "chats"):
+        if not isinstance(data.get(key), list):
+            continue
+        for c in data[key]:
+            if not isinstance(c, dict):
+                continue
+            msgs = c.get("messages")
+            if isinstance(msgs, list):
+                for m in msgs:
+                    if isinstance(m, dict):
+                        yield m
+
+
+def _parse_augment_export_data(data):
+    """Parse Augment ("Augument") export JSON into normalized loglines.
+
+    Returns {"loglines": [...]} on success, or None if the data does not look like an Augment export.
+    """
+    loglines = []
+    saw_any_message = False
+
+    for idx, msg in enumerate(_iter_augment_message_dicts(data), start=1):
+        saw_any_message = True
+
+        role = (
+            _normalize_role_to_user_or_assistant(msg.get("role"))
+            or _normalize_role_to_user_or_assistant(msg.get("sender"))
+            or _normalize_role_to_user_or_assistant(msg.get("from"))
+            or _normalize_role_to_user_or_assistant(msg.get("author"))
+        )
+        if role not in ("user", "assistant"):
+            continue
+
+        ts = _coerce_timestamp_to_iso_z(
+            msg.get("created_at")
+            or msg.get("createdAt")
+            or msg.get("timestamp")
+            or msg.get("time")
+            or msg.get("date")
+        )
+        if not ts:
+            ts = f"unknown-{idx:04d}"
+
+        text = _extract_text_from_maybe_rich_content(
+            msg.get("content")
+            if "content" in msg
+            else msg.get("text", msg.get("message", msg.get("body", "")))
+        )
+
+        # Prefer Claude-style content blocks for assistant so Markdown renders correctly
+        if role == "assistant":
+            content = [{"type": "text", "text": text}]
+        else:
+            content = text
+
+        loglines.append(
+            {
+                "type": role,
+                "timestamp": ts,
+                "message": {"role": role, "content": content},
+            }
+        )
+
+    if loglines:
+        return {"loglines": loglines}
+    if saw_any_message:
+        # Data had messages but none were user/assistant; treat as non-Augment.
+        return None
+    return None
 
 
 def _is_codex_cli_format(filepath):
diff --git a/tests/sample_augment_export.json b/tests/sample_augment_export.json
new file mode 100644
index 0000000..74346e4
--- /dev/null
+++ b/tests/sample_augment_export.json
@@ -0,0 +1,35 @@
+{
+  "app": "Augument",
+  "version": "1.0",
+  "exported_at": "2026-01-01T12:00:00Z",
+  "conversation": {
+    "id": "conv-1",
+    "title": "Test conversation",
+    "messages": [
+      {
+        "id": "m1",
+        "role": "user",
+        "content": "Hello **Augment**",
+        "created_at": "2026-01-01T12:00:01Z"
+      },
+      {
+        "id": "m2",
+        "role": "assistant",
+        "content": "Hi there!\n\n```python\nprint('hi')\n```",
+        "created_at": "2026-01-01T12:00:02Z"
+      },
+      {
+        "id": "m3",
+        "role": "user",
+        "content": "Thanks",
+        "created_at": "2026-01-01T12:00:03Z"
+      },
+      {
+        "id": "m4",
+        "role": "assistant",
+        "content": "You're welcome.",
+        "created_at": "2026-01-01T12:00:04Z"
+      }
+    ]
+  }
+}
diff --git a/tests/test_augment_format.py b/tests/test_augment_format.py
new file mode 100644
index 0000000..f5d67e1
--- /dev/null
+++ b/tests/test_augment_format.py
@@ -0,0 +1,92 @@
+"""Tests for Augment ("Augument") export format support."""
+
+import json
+from pathlib import Path
+
+import pytest
+
+from claude_code_transcripts import generate_html, parse_session_file
+
+
+class TestAugmentExportParsing:
+    def test_parses_sample_augment_export(self):
+        fixture_path = Path(__file__).parent / "sample_augment_export.json"
+        data = parse_session_file(fixture_path)
+
+        assert "loglines" in data
+        assert [e["type"] for e in data["loglines"]] == [
+            "user",
+            "assistant",
+            "user",
+            "assistant",
+        ]
+
+        first = data["loglines"][0]
+        assert first["timestamp"] == "2026-01-01T12:00:01Z"
+        assert first["message"]["role"] == "user"
+        assert first["message"]["content"] == "Hello **Augment**"
+
+        second = data["loglines"][1]
+        assert second["timestamp"] == "2026-01-01T12:00:02Z"
+        assert second["message"]["role"] == "assistant"
+        # Ensure assistant content is markdown-renderable (Claude-style content blocks)
+        assert isinstance(second["message"]["content"], list)
+        assert second["message"]["content"][0]["type"] == "text"
+        assert "print('hi')" in second["message"]["content"][0]["text"]
+
+    @pytest.mark.parametrize(
+        "payload",
+        [
+            # Minimal dict with top-level messages list
+            {
+                "messages": [
+                    {"role": "USER", "text": "hi", "timestamp": 1735732800},
+                    {"role": "ASSISTANT", "text": "hello", "timestamp": 1735732801},
+                ]
+            },
+            # Conversation wrapper, alternate keys
+            {
+                "conversation": {
+                    "messages": [
+                        {
+                            "sender": "user",
+                            "content": "hi",
+                            "createdAt": "2026-01-01T00:00:00Z",
+                        },
+                        {
+                            "sender": "assistant",
+                            "message": "hello",
+                            "createdAt": "2026-01-01T00:00:01Z",
+                        },
+                    ]
+                }
+            },
+        ],
+    )
+    def test_parses_common_augment_variants(self, tmp_path, payload):
+        p = tmp_path / "augment.json"
+        p.write_text(json.dumps(payload), encoding="utf-8")
+
+        data = parse_session_file(p)
+        assert "loglines" in data
+        assert len(data["loglines"]) == 2
+        assert data["loglines"][0]["type"] == "user"
+        assert data["loglines"][1]["type"] == "assistant"
+
+
+class TestAugmentHtmlGeneration:
+    def test_generates_html_from_augment_export(self, tmp_path):
+        fixture_path = Path(__file__).parent / "sample_augment_export.json"
+        output_dir = tmp_path / "out"
+
+        generate_html(fixture_path, output_dir)
+
+        index_html = (output_dir / "index.html").read_text(encoding="utf-8")
+        assert "Hello" in index_html
+        # User markdown is rendered
+        assert "<strong>Augment</strong>" in index_html
+
+        # Assistant content (including code blocks) is rendered on the per-page transcript
+        page_html = (output_dir / "page-001.html").read_text(encoding="utf-8")
+        assert "print" in page_html
+        assert "hi" in page_html