diff --git a/mempalace/miner.py b/mempalace/miner.py
index f0177fa..4e809a8 100644
--- a/mempalace/miner.py
+++ b/mempalace/miner.py
@@ -63,7 +63,11 @@ SKIP_FILENAMES = {
 CHUNK_SIZE = 800  # chars per drawer
 CHUNK_OVERLAP = 100  # overlap between chunks
 MIN_CHUNK_SIZE = 50  # skip tiny chunks
-MAX_FILE_SIZE = 10 * 1024 * 1024  # 10 MB — skip files larger than this
+MAX_FILE_SIZE = 500 * 1024 * 1024  # 500 MB — skip files larger than this.
+# Long Claude Code sessions and large transcript exports routinely exceed
+# 10 MB. The cap exists as a defensive rail against pathological binary
+# files, not as a limit on legitimate text. Chunking at 800 chars per
+# drawer means source size does not affect storage or embedding cost.
 
 
 # =============================================================================
diff --git a/tests/test_miner_jsonl_visibility.py b/tests/test_miner_jsonl_visibility.py
index 6d24670..2ef3e18 100644
--- a/tests/test_miner_jsonl_visibility.py
+++ b/tests/test_miner_jsonl_visibility.py
@@ -23,8 +23,9 @@ Written BEFORE the fix.
 
 import tempfile
 from pathlib import Path
+from unittest.mock import patch
 
-from mempalace.miner import READABLE_EXTENSIONS, scan_project
+from mempalace.miner import MAX_FILE_SIZE, READABLE_EXTENSIONS, scan_project
 
 
 class TestJsonlNotSilentlySkipped:
@@ -67,3 +68,57 @@ class TestJsonlNotSilentlySkipped:
                 f"Returned: {found_names}. Users placing transcript "
                 "exports in a project directory expect them to be mined."
             )
+
+    def test_large_jsonl_not_silently_dropped_by_size_cap(self):
+        """Long sessions produce >10 MB transcripts. They must still mine.
+
+        The legacy cap was 10 MB, which is smaller than a long Claude Code
+        session's transcript. Users hitting the cap lost their entire
+        conversation to a silent `if size > MAX: continue` at miner.py:732.
+        Raise the cap well above any realistic transcript size.
+        """
+        # 10 MB cap was silent failure — real Claude Code long sessions
+        # exceed this. The cap must accommodate them.
+        assert MAX_FILE_SIZE >= 100 * 1024 * 1024, (
+            f"MAX_FILE_SIZE is {MAX_FILE_SIZE} bytes "
+            f"({MAX_FILE_SIZE / 1024 / 1024:.0f} MB). Long Claude Code "
+            "sessions produce transcripts larger than 10 MB and get "
+            "silently dropped. Raise to at least 100 MB — chunking "
+            "at 800 chars per drawer means source file size doesn't "
+            "matter for downstream storage."
+        )
+
+    def test_scan_project_picks_up_50mb_jsonl(self):
+        """A 50 MB .jsonl must not be filtered out by the size cap.
+
+        We don't actually write 50 MB (slow test). Instead, we mock
+        stat().st_size to report a 50 MB file and confirm scan_project
+        still includes it.
+        """
+        with tempfile.TemporaryDirectory() as tmp:
+            tmpdir = Path(tmp)
+            big_jsonl = tmpdir / "big_transcript.jsonl"
+            # Write a small real file so the existence / extension / text
+            # checks pass; then mock its reported size.
+            big_jsonl.write_text('{"role": "user", "content": "hi"}\n')
+            fake_size = 50 * 1024 * 1024  # 50 MB
+
+            real_stat = Path.stat
+
+            def fake_stat(self, *args, **kwargs):
+                result = real_stat(self, *args, **kwargs)
+                if self.name == "big_transcript.jsonl":
+                    class _FakeStat:
+                        st_size = fake_size
+                        st_mode = result.st_mode
+                    return _FakeStat()
+                return result
+
+            with patch.object(Path, "stat", fake_stat):
+                found = scan_project(str(tmpdir))
+
+            found_names = [p.name for p in found]
+            assert "big_transcript.jsonl" in found_names, (
+                f"50 MB .jsonl was dropped by size cap (MAX_FILE_SIZE="
+                f"{MAX_FILE_SIZE}). Returned: {found_names}."
+            )