diff --git a/CLAUDE.md b/CLAUDE.md
index c2892d6..ba8be79 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -73,6 +73,28 @@ should not import from `sfm/`, must not touch a DB, and have no I/O
 beyond reading files passed as arguments.  Keep them pure — both
 tiers can then depend on them without circularity.
 
+#### Thor IDF binary codec (2026-05-28)
+
+`micromate/idf_file.read_idf_file()` decodes both Thor IDFW
+(waveform) and IDFH (histogram) binaries.
+
+- **IDFW** reuses `decode_waveform_v2()` on the body at fixed file
+  offset `0x0f1f`.  Sample fidelity is 87–99% byte-exact on quiet
+  events; loud events hit the BW codec's known walker-stops-early
+  limitation.
+- **IDFH** has its own segment-based decoder: `[len_be][0a 00 00 00]
+  [00 NN][05 3f]` + N × 72-byte interval records (4 × 16-byte
+  per-channel min/max/halfp).  All 859 Thor IDFH corpus files
+  decode (181,071 intervals); peak matches sidecar within ~1.8%
+  (ADC quantization).
+
+The two outlier `BE9439_*` files in the Thor example corpus are
+actually Series III Blastware binaries that share the `.IDFW`/`.IDFH`
+filename convention by accident.  `read_idf_file()` detects them by
+their BW STRT signature and raises NotImplementedError pointing
+callers at `read_blastware_file()`.  See
+`docs/idf_protocol_reference.md` for full field layouts.
+
 ### Practical consequences
 
 When deciding where new code goes, ask:
diff --git a/analysis_idf/corpus_accuracy.py b/analysis_idf/corpus_accuracy.py
new file mode 100644
index 0000000..acdd0e9
--- /dev/null
+++ b/analysis_idf/corpus_accuracy.py
@@ -0,0 +1,65 @@
+"""Run read_idf_file across the corpus and report per-channel accuracy vs sidecars."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from micromate.idf_file import read_idf_file
+from analysis_idf.recon import load_sidecar_samples
+
+
+def sidecar_path(idfw: Path) -> Path:
+    return idfw.parent / "TXT" / f"{idfw.name}.txt"
+
+
+def main():
+    root = REPO / "tests/fixtures/THORDATA_example"
+    files = [f for f in root.rglob("*.IDFW") if not str(f).endswith(".CDB")]
+    files.sort()
+    GEO_LSB = 0.0003
+
+    n_ok = n_skip = 0
+    overall = {"Tran": [], "Vert": [], "Long": []}
+
+    for f in files:
+        try:
+            res = read_idf_file(f)
+        except Exception:
+            n_skip += 1
+            continue
+        sc_path = sidecar_path(f)
+        if not sc_path.exists():
+            n_skip += 1
+            continue
+        try:
+            sc = load_sidecar_samples(sc_path)
+        except Exception:
+            n_skip += 1
+            continue
+
+        per_file = {}
+        for ch in ("Tran", "Vert", "Long"):
+            sc_counts = [int(round(v / GEO_LSB)) for v in sc[ch]]
+            dec = res.samples.get(ch, [])
+            n = min(len(sc_counts), len(dec))
+            if n == 0:
+                per_file[ch] = 0.0
+                continue
+            exact = sum(1 for i in range(n) if sc_counts[i] == dec[i])
+            pct = 100.0 * exact / n
+            per_file[ch] = pct
+            overall[ch].append(pct)
+        n_ok += 1
+
+    print(f"Processed {n_ok} files (skipped {n_skip})")
+    print("Per-channel exact-match % (mean / min / max):")
+    for ch, vals in overall.items():
+        if vals:
+            avg = sum(vals) / len(vals)
+            print(f"  {ch}: mean={avg:.2f}%  min={min(vals):.2f}%  max={max(vals):.2f}%  n={len(vals)}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/diff_trail.py b/analysis_idf/diff_trail.py
new file mode 100644
index 0000000..a64295b
--- /dev/null
+++ b/analysis_idf/diff_trail.py
@@ -0,0 +1,49 @@
+"""Find where decoded-vs-sidecar diverges for each channel."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import decode_waveform_v2
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    sc = load_sidecar_samples(TXT)
+    decoded = decode_waveform_v2(buf[0x0f1f:])
+    GEO_LSB = 0.0003
+
+    for ch in ("Tran", "Vert", "Long"):
+        sc_counts = [int(round(v / GEO_LSB)) for v in sc[ch]]
+        dec = decoded[ch]
+        # Find ALL transitions where mismatches start/stop
+        first_diff = next((i for i in range(len(dec)) if dec[i] != sc_counts[i]), None)
+        if first_diff is None:
+            print(f"{ch}: NO MISMATCHES")
+            continue
+        print(f"{ch}: first diff at idx {first_diff}")
+        # Show 5 before, 5 after
+        for i in range(max(0, first_diff - 3), min(len(dec), first_diff + 8)):
+            mark = "  " if dec[i] == sc_counts[i] else "**"
+            print(f"  {mark} idx {i:4d}: sc={sc_counts[i]:6d}  dec={dec[i]:6d}  diff={dec[i]-sc_counts[i]:+d}")
+        # Where does cumulative diff exceed 100?
+        cum_match_run = 0
+        max_match_run = 0
+        match_run_start = 0
+        diff_count = 0
+        for i in range(len(dec)):
+            if dec[i] == sc_counts[i]:
+                cum_match_run += 1
+                max_match_run = max(max_match_run, cum_match_run)
+            else:
+                cum_match_run = 0
+                diff_count += 1
+        print(f"  total mismatches: {diff_count}/{len(dec)}, longest run of matches: {max_match_run}")
+        print()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/e2e_idfh.py b/analysis_idf/e2e_idfh.py
new file mode 100644
index 0000000..3f5ec43
--- /dev/null
+++ b/analysis_idf/e2e_idfh.py
@@ -0,0 +1,48 @@
+"""End-to-end IDFH ingest verification."""
+from __future__ import annotations
+import sys
+import tempfile
+import json
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from sfm.waveform_store import WaveformStore
+
+
+def main():
+    idfh = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM13981/UM13981_20220805075441.IDFH"
+    txt  = idfh.parent / "TXT" / f"{idfh.name}.txt"
+
+    with tempfile.TemporaryDirectory() as td:
+        store = WaveformStore(Path(td))
+        ev, rec = store.save_imported_idf(
+            idfh.read_bytes(),
+            idfh,
+            idf_report_text=txt.read_text(errors="replace"),
+        )
+        print("=== save_imported_idf (IDFH) ===")
+        print(f"  serial:        {rec['serial']}")
+        print(f"  filename:      {rec['filename']}")
+        print(f"  filesize:      {rec['filesize']}")
+        print(f"  h5:            {rec['hdf5_filename']}")  # expect None for histogram
+        print(f"  sidecar:       {rec['sidecar_filename']}")
+        print()
+        print("=== Event ===")
+        print(f"  timestamp:     {ev.timestamp}")
+        print(f"  record_type:   {ev.record_type}")
+        print(f"  sample_rate:   {ev.sample_rate}")
+        print()
+        # Inspect sidecar to confirm intervals were stashed
+        sc_path = Path(td) / "UM13981" / f"{idfh.name}.sfm.json"
+        sc = json.loads(sc_path.read_text())
+        intervals = sc.get("extensions", {}).get("idf_intervals", [])
+        print(f"  sidecar intervals: {len(intervals)}")
+        if intervals:
+            print(f"  first interval:    {intervals[0]}")
+            print(f"  last interval:     {intervals[-1]}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/e2e_no_txt.py b/analysis_idf/e2e_no_txt.py
new file mode 100644
index 0000000..a9c81b6
--- /dev/null
+++ b/analysis_idf/e2e_no_txt.py
@@ -0,0 +1,40 @@
+"""Verify the had_report=False path: ingest IDFW with no .txt."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+import tempfile
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from sfm.waveform_store import WaveformStore
+
+
+def main():
+    idfw = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162723.IDFW"
+    with tempfile.TemporaryDirectory() as td:
+        store = WaveformStore(Path(td))
+        ev, rec = store.save_imported_idf(
+            idfw.read_bytes(),
+            idfw,
+            serial_hint=None,
+            idf_report_text=None,        # ← no .txt!
+        )
+        print("=== IDFW without .txt ingest ===")
+        print(f"  serial:        {rec['serial']}")
+        print(f"  timestamp:     {ev.timestamp}")
+        print(f"  sample_rate:   {ev.sample_rate}")
+        print(f"  record_type:   {ev.record_type}")
+        print(f"  rectime_sec:   {ev.rectime_seconds}")
+        nT = len(ev.raw_samples.get('Tran', [])) if ev.raw_samples else 0
+        nV = len(ev.raw_samples.get('Vert', [])) if ev.raw_samples else 0
+        nL = len(ev.raw_samples.get('Long', [])) if ev.raw_samples else 0
+        nM = len(ev.raw_samples.get('MicL', [])) if ev.raw_samples else 0
+        print(f"  raw_samples:   Tran={nT} Vert={nV} Long={nL} MicL={nM}")
+        if ev.peak_values:
+            print(f"  peak_values:   tran={ev.peak_values.tran} vert={ev.peak_values.vert} long={ev.peak_values.long}")
+        print(f"  h5 written:    {rec['hdf5_filename']}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/e2e_save_idf.py b/analysis_idf/e2e_save_idf.py
new file mode 100644
index 0000000..87e9650
--- /dev/null
+++ b/analysis_idf/e2e_save_idf.py
@@ -0,0 +1,52 @@
+"""End-to-end ingest test: feed an IDFW + .txt to save_imported_idf in a tmp store."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+import tempfile
+import shutil
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from sfm.waveform_store import WaveformStore
+
+
+def main():
+    idfw = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162723.IDFW"
+    txt  = idfw.parent / "TXT" / f"{idfw.name}.txt"
+
+    with tempfile.TemporaryDirectory() as td:
+        store = WaveformStore(Path(td))
+        ev, rec = store.save_imported_idf(
+            idfw.read_bytes(),
+            idfw,
+            serial_hint=None,
+            idf_report_text=txt.read_text(errors="replace"),
+        )
+        print("=== Save result ===")
+        print(f"  serial:    {rec['serial']}")
+        print(f"  filename:  {rec['filename']}")
+        print(f"  filesize:  {rec['filesize']}")
+        print(f"  h5:        {rec['hdf5_filename']}")
+        print(f"  sidecar:   {rec['sidecar_filename']}")
+        print()
+        print("=== Event ===")
+        print(f"  serial:        {ev.serial if hasattr(ev,'serial') else '(n/a)'}")
+        print(f"  timestamp:     {ev.timestamp}")
+        print(f"  sample_rate:   {ev.sample_rate}")
+        print(f"  record_type:   {ev.record_type}")
+        print(f"  rectime_sec:   {ev.rectime_seconds}")
+        print(f"  raw_samples:   Tran={len(ev.raw_samples.get('Tran', [])) if ev.raw_samples else 0}, Vert={len(ev.raw_samples.get('Vert', [])) if ev.raw_samples else 0}, Long={len(ev.raw_samples.get('Long', [])) if ev.raw_samples else 0}, MicL={len(ev.raw_samples.get('MicL', [])) if ev.raw_samples else 0}")
+        if ev.peak_values:
+            print(f"  peaks (txt):   Tran={ev.peak_values.tran} Vert={ev.peak_values.vert} Long={ev.peak_values.long}")
+        print()
+
+        # Verify the h5 file actually got written
+        h5path = Path(td) / "UM11719" / f"{idfw.name}.h5"
+        print(f"  h5 exists:     {h5path.exists()}  size={h5path.stat().st_size if h5path.exists() else 0}")
+        sidecar = Path(td) / "UM11719" / f"{idfw.name}.sfm.json"
+        print(f"  sidecar exists:{sidecar.exists()}  size={sidecar.stat().st_size if sidecar.exists() else 0}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/idfh_decode.py b/analysis_idf/idfh_decode.py
new file mode 100644
index 0000000..ae4354a
--- /dev/null
+++ b/analysis_idf/idfh_decode.py
@@ -0,0 +1,137 @@
+"""Decode IDFH histogram intervals + verify against sidecar."""
+from __future__ import annotations
+import sys
+import struct
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+
+SEGMENT_MAGIC = b"\x02\xda\x0a\x00\x00\x00"
+SEGMENT_SIZE = 732   # = 10-byte header + 10 × 72-byte intervals + 2-byte tail
+INTERVAL_SIZE = 72
+CHANNELS = ("Tran", "Vert", "Long", "MicL")
+
+
+def decode_interval(buf72: bytes) -> dict:
+    """Decode one 72-byte interval into per-channel min/max/halfp."""
+    out = {}
+    for i, ch in enumerate(CHANNELS):
+        block = buf72[i*16 : (i+1)*16]
+        mn = struct.unpack_from(">h", block, 0)[0]
+        mx = struct.unpack_from(">h", block, 2)[0]
+        sb = struct.unpack_from(">h", block, 4)[0]
+        halfp = struct.unpack_from(">H", block, 6)[0]
+        f10 = struct.unpack_from(">H", block, 10)[0]
+        f14 = struct.unpack_from(">H", block, 14)[0]
+        peak_count = max(abs(mn), abs(mx))
+        out[ch] = {
+            "min":     mn,
+            "max":     mx,
+            "field4":  sb,
+            "halfp":   halfp,
+            "field10": f10,
+            "field14": f14,
+            "peak":    peak_count,
+            "freq_hz": (512.0 / halfp) if halfp > 5 else None,
+        }
+    out["_tail"] = buf72[64:].hex(" ")
+    return out
+
+
+def walk_idfh(buf: bytes) -> list:
+    """Walk all interval records in an IDFH file."""
+    intervals = []
+    # Multi-segment file: every 02 da 0a 00 00 00 marker introduces a segment.
+    # Single-interval file: just one body header at 0xf96 of form ?? ?? 0a 00 00 00.
+    # Find them all.
+    i = 0
+    while True:
+        j = buf.find(b"\x0a\x00\x00\x00", i)
+        if j < 0:
+            break
+        # Validate: the 2 bytes before must form a length, and we want bytes
+        # [j-2 : j+6] to have a recognisable shape.  Actually the cleanest
+        # filter is "preceded by a length and followed by 00 NN 05 3f".
+        if j < 2:
+            i = j + 1
+            continue
+        # Body header form: [length_be_2][0a 00 00 00][00 NN][05 3f]
+        if j + 10 > len(buf):
+            break
+        length = int.from_bytes(buf[j-2:j], "big")
+        # Verify the segment-marker shape: [length_be][0a 00 00 00][00 NN][05 3f]
+        if buf[j+4] != 0x00:
+            i = j + 1
+            continue
+        if buf[j+6:j+8] != b"\x05\x3f":
+            i = j + 1
+            continue
+        # Header layout (10 bytes): [length_be 2B][0a 00 00 00 4B][00 NN 2B][05 3f 2B]
+        # Followed by N interval records of 72 bytes each, then 2 tail bytes.
+        # length value = (N × 72) + 10  (counts bytes from 0x0a... through interval data).
+        header_start = j - 2
+        n_intervals = (length - 10) // INTERVAL_SIZE
+        interval_start = header_start + 10
+        for k in range(n_intervals):
+            off = interval_start + k * INTERVAL_SIZE
+            if off + INTERVAL_SIZE > len(buf):
+                break
+            chunk = buf[off:off + INTERVAL_SIZE]
+            intervals.append({"offset": off, **decode_interval(chunk)})
+        i = header_start + length + 2
+    return intervals
+
+
+def main():
+    # Test against multi-segment IDFH
+    target = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM13981/UM13981_20220805075441.IDFH"
+    sc_path = target.parent / "TXT" / f"{target.name}.txt"
+    buf = target.read_bytes()
+    intervals = walk_idfh(buf)
+    print(f"=== {target.name} ===")
+    print(f"  file size: {len(buf)}")
+    print(f"  decoded intervals: {len(intervals)}")
+    # Show first 2 + last 2
+    sc_rows = []
+    for line in sc_path.read_text(errors="replace").splitlines():
+        if line.startswith("2022-") or line.startswith("2023-"):
+            sc_rows.append(line)
+    print(f"  sidecar rows: {len(sc_rows)}")
+
+    print()
+    for k in [0, 1, 78, 79, 80]:
+        if k >= len(intervals):
+            continue
+        iv = intervals[k]
+        print(f"--- interval {k} @0x{iv['offset']:04x} ---")
+        for ch in CHANNELS:
+            d = iv[ch]
+            peak_ips = d["peak"] / 32768 * 10.0
+            print(f"  {ch}: peak={d['peak']:5d} ({peak_ips:.4f} in/s)  halfp={d['halfp']:5d}  freq={d['freq_hz']}")
+        # sidecar row
+        if k < len(sc_rows):
+            print(f"  SC: {sc_rows[k]}")
+
+    # Test single-interval IDFH
+    print()
+    target2 = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162648.IDFH"
+    sc2 = target2.parent / "TXT" / f"{target2.name}.txt"
+    buf2 = target2.read_bytes()
+    intervals2 = walk_idfh(buf2)
+    print(f"=== {target2.name} ===")
+    print(f"  file size: {len(buf2)}, decoded intervals: {len(intervals2)}")
+    if intervals2:
+        iv = intervals2[0]
+        for ch in CHANNELS:
+            d = iv[ch]
+            peak_ips = d["peak"] / 32768 * 10.0
+            print(f"  {ch}: peak={d['peak']:5d} ({peak_ips:.4f} in/s)  halfp={d['halfp']:5d}  freq={d['freq_hz']}")
+        sc_rows2 = [l for l in sc2.read_text(errors='replace').splitlines() if l.startswith("2023-")]
+        if sc_rows2:
+            print(f"  SC: {sc_rows2[0]}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/idfh_period.py b/analysis_idf/idfh_period.py
new file mode 100644
index 0000000..8aad756
--- /dev/null
+++ b/analysis_idf/idfh_period.py
@@ -0,0 +1,41 @@
+"""Find IDFH interval period via auto-correlation of structural patterns."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+from collections import Counter
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+
+def main():
+    target = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM13981/UM13981_20220805075441.IDFH"
+    buf = target.read_bytes()
+    body_start = 0xF96
+    body_end   = 0x270C
+    body = buf[body_start:body_end]
+    print(f"body size: {len(body)} bytes (file {len(buf)} bytes)")
+
+    # For each candidate interval size, count how many bytes at fixed offsets within
+    # each interval are zero (consistent column-zero pattern indicates correct size).
+    print()
+    print("=== zero-column score by interval size (higher = more likely) ===")
+    best = []
+    for sz in range(16, 100):
+        n = len(body) // sz
+        if n < 30:
+            continue
+        # For each column position within an interval, count how many of n intervals have zero
+        score = 0
+        for col in range(sz):
+            zeros = sum(1 for i in range(n) if body[i*sz + col] == 0)
+            if zeros >= n * 0.9:
+                score += 1
+        best.append((score, sz, n))
+    best.sort(reverse=True)
+    for score, sz, n in best[:10]:
+        print(f"  size={sz:3d}  n_intervals={n}  consistently-zero-cols={score}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/per_file_detail.py b/analysis_idf/per_file_detail.py
new file mode 100644
index 0000000..b9040f3
--- /dev/null
+++ b/analysis_idf/per_file_detail.py
@@ -0,0 +1,40 @@
+"""Per-file accuracy + sample-count details."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from micromate.idf_file import read_idf_file
+from analysis_idf.recon import load_sidecar_samples
+
+
+def main():
+    root = REPO / "tests/fixtures/THORDATA_example"
+    files = sorted([f for f in root.rglob("*.IDFW") if not str(f).endswith(".CDB")])
+    GEO_LSB = 0.0003
+    # Limit to first 15 successful files for detail.
+    shown = 0
+    for f in files:
+        try:
+            res = read_idf_file(f)
+        except Exception:
+            continue
+        sc_path = f.parent / "TXT" / f"{f.name}.txt"
+        if not sc_path.exists():
+            continue
+        sc = load_sidecar_samples(sc_path)
+        sc_tran = [int(round(v / GEO_LSB)) for v in sc["Tran"]]
+        dec = res.samples.get("Tran", [])
+        n = min(len(sc_tran), len(dec))
+        exact = sum(1 for i in range(n) if sc_tran[i] == dec[i]) if n else 0
+        pct = 100.0 * exact / n if n else 0.0
+        print(f"{f.name:40s}  size={f.stat().st_size:6d}  sc_n={len(sc_tran):4d}  dec_n={len(dec):4d}  exact={pct:.1f}%")
+        shown += 1
+        if shown >= 20:
+            break
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/probe_boundary.py b/analysis_idf/probe_boundary.py
new file mode 100644
index 0000000..bbf2722
--- /dev/null
+++ b/analysis_idf/probe_boundary.py
@@ -0,0 +1,64 @@
+"""Look at what's at the divergence boundary."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import walk_body, find_data_start, parse_segment_header
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    body = buf[0x0f1f:]
+    start = find_data_start(body)
+    print(f"data_start: {start}  (= file offset 0x{0x0f1f + start:04x})")
+
+    blocks = walk_body(body, start)
+    print(f"{len(blocks)} blocks total")
+    print()
+
+    # First 25 blocks
+    print("=== first 30 blocks ===")
+    for i, b in enumerate(blocks[:30]):
+        body_off = 0x0f1f + b.offset
+        if b.tag_hi == 0x40:
+            hdr = parse_segment_header(b)
+            print(f"  [{i:3d}] @0x{body_off:04x}  {b.kind}  (segment header)  counter={hdr['counter'] if hdr else '?'}  field2={hdr['field2'].hex() if hdr else '?'}  anchor={hdr['anchor_bytes'].hex() if hdr else '?'}  tail={hdr['tail'].hex() if hdr else '?'}")
+        else:
+            print(f"  [{i:3d}] @0x{body_off:04x}  {b.kind}  len={b.length}  data={b.data[:16].hex()}")
+    print()
+
+    # Cumulative sample counts per block to find which block contains sample 254
+    print("=== cumulative samples through blocks ===")
+    cur_ch = "Tran"
+    rotation = ["Vert", "Long", "MicL", "Tran"]
+    seg_count = 0
+    samples_in_curseg = 2  # preamble Tran[0], Tran[1]
+    for i, b in enumerate(blocks[:30]):
+        if b.tag_hi == 0x40:
+            seg_count += 1
+            prev_ch = cur_ch
+            cur_ch = rotation[(seg_count - 1) % 4]
+            print(f"  [{i:3d}] 40 02 -> end of {prev_ch} segment, start {cur_ch} (segment {seg_count})")
+            samples_in_curseg = 2  # anchors
+        elif (b.tag_hi & 0xF0) == 0x10:
+            nn = ((b.tag_hi & 0x0F) << 8) | b.tag_lo
+            samples_in_curseg += nn
+            print(f"  [{i:3d}] {b.kind} nibble: +{nn} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif (b.tag_hi & 0xF0) == 0x20:
+            nn = ((b.tag_hi & 0x0F) << 8) | b.tag_lo
+            samples_in_curseg += nn
+            print(f"  [{i:3d}] {b.kind} int8: +{nn} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif b.tag_hi == 0x00:
+            samples_in_curseg += b.tag_lo
+            print(f"  [{i:3d}] {b.kind} RLE: +{b.tag_lo}, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif b.tag_hi == 0x30:
+            samples_in_curseg += b.tag_lo
+            print(f"  [{i:3d}] {b.kind} packed12: +{b.tag_lo} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/recon.py b/analysis_idf/recon.py
new file mode 100644
index 0000000..f87a060
--- /dev/null
+++ b/analysis_idf/recon.py
@@ -0,0 +1,89 @@
+"""Reconnaissance helpers for cracking the Thor IDFW binary."""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+TARGET = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162723.IDFW"
+TXT = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/TXT/UM11719_20231219162723.IDFW.txt"
+
+
+def hex_at(buf: bytes, off: int, n: int = 32) -> str:
+    chunk = buf[off : off + n]
+    hexs = " ".join(f"{b:02x}" for b in chunk)
+    asc = "".join(chr(b) if 32 <= b < 127 else "." for b in chunk)
+    return f"{off:04x}: {hexs}  {asc}"
+
+
+def find_all(buf: bytes, needle: bytes) -> list[int]:
+    out: list[int] = []
+    i = 0
+    while True:
+        j = buf.find(needle, i)
+        if j < 0:
+            break
+        out.append(j)
+        i = j + 1
+    return out
+
+
+def load_sidecar_samples(path: Path) -> dict[str, list[float]]:
+    """Parse the txt sample table — Tran/Vert/Long/MicL."""
+    out = {"Tran": [], "Vert": [], "Long": [], "MicL": []}
+    in_block = False
+    for line in path.read_text(errors="replace").splitlines():
+        if not in_block:
+            if line.strip() == "Waveform Data Channels":
+                in_block = True
+            continue
+        if line.startswith("Waveform Data USB Channels"):
+            break
+        parts = line.split("\t")
+        # First row is the header "\tTran\tVert\tLong\tMicL"
+        if len(parts) >= 5 and parts[1] == "Tran":
+            continue
+        if len(parts) < 5:
+            continue
+        try:
+            out["Tran"].append(float(parts[1]))
+            out["Vert"].append(float(parts[2]))
+            out["Long"].append(float(parts[3]))
+            out["MicL"].append(float(parts[4]))
+        except ValueError:
+            continue
+    return out
+
+
+def main():
+    buf = TARGET.read_bytes()
+    samples = load_sidecar_samples(TXT)
+    print(f"file size: {len(buf)} bytes")
+    print(f"sample rows: Tran={len(samples['Tran'])} Vert={len(samples['Vert'])} Long={len(samples['Long'])} MicL={len(samples['MicL'])}")
+    print(f"first 6 Tran samples: {samples['Tran'][:6]}")
+    print(f"first 6 Vert samples: {samples['Vert'][:6]}")
+    print(f"first 6 Long samples: {samples['Long'][:6]}")
+    print(f"first 6 MicL samples: {samples['MicL'][:6]}")
+
+    print()
+    print("=== BW magic '00 02 00' positions ===")
+    hits = find_all(buf, b"\x00\x02\x00")
+    print(f"{len(hits)} hits")
+    for h in hits[:20]:
+        print(hex_at(buf, h, 24))
+
+    print()
+    print("=== '40 02' segment-header positions ===")
+    hits = find_all(buf, b"\x40\x02")
+    print(f"{len(hits)} hits")
+    for h in hits:
+        ctx_pre = buf[max(0, h - 4): h].hex()
+        ctx_post = buf[h: h + 20].hex()
+        # Show byte preceding to help identify real headers vs casual occurrences
+        print(f"  0x{h:04x}  pre={ctx_pre}  post={ctx_post}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/seg_resync.py b/analysis_idf/seg_resync.py
new file mode 100644
index 0000000..6697cc8
--- /dev/null
+++ b/analysis_idf/seg_resync.py
@@ -0,0 +1,40 @@
+"""Find each segment boundary in the channel and check if errors reset there."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import decode_waveform_v2
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    sc = load_sidecar_samples(TXT)
+    decoded = decode_waveform_v2(buf[0x0f1f:])
+    GEO_LSB = 0.0003
+
+    for ch in ("Tran", "Vert", "Long"):
+        sc_counts = [int(round(v / GEO_LSB)) for v in sc[ch]]
+        dec = decoded[ch]
+        # Find every transition where error becomes zero from nonzero (or grows from zero)
+        # Print indices where dec resyncs back to exact match.
+        n = min(len(sc_counts), len(dec))
+        events = []
+        prev_match = True
+        for i in range(n):
+            match = sc_counts[i] == dec[i]
+            if match != prev_match:
+                kind = "RESYNC" if match else "DIVERGE"
+                events.append((i, kind, sc_counts[i], dec[i]))
+                prev_match = match
+        print(f"{ch}: {len(events)} transitions")
+        for i, kind, sc_v, dec_v in events[:20]:
+            print(f"  idx {i:4d}  {kind:8s}  sc={sc_v:6d}  dec={dec_v:6d}  diff={dec_v-sc_v:+d}")
+        print()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/smoke_idfh.py b/analysis_idf/smoke_idfh.py
new file mode 100644
index 0000000..ab1eb64
--- /dev/null
+++ b/analysis_idf/smoke_idfh.py
@@ -0,0 +1,46 @@
+"""Smoke-test read_idf_file on IDFH across the corpus."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from micromate.idf_file import read_idf_file
+
+
+def main():
+    target = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162648.IDFH"
+    result = read_idf_file(target)
+    ev = result.event
+    print(f"=== {target.name} ===")
+    print(f"  signature:   {result.signature}")
+    print(f"  serial:      {ev.serial}")
+    print(f"  timestamp:   {ev.timestamp}")
+    print(f"  sample_rate: {ev.sample_rate}")
+    print(f"  kind:        {ev.kind}")
+    print(f"  intervals:   {len(result.intervals or [])}")
+    print(f"  peaks:       T={ev.peaks.transverse_ips:.4f} V={ev.peaks.vertical_ips:.4f} L={ev.peaks.longitudinal_ips:.4f}")
+    print()
+
+    root = REPO / "tests/fixtures/THORDATA_example"
+    files = list(root.rglob("*.IDFH"))
+    ok = fail = nyi = 0
+    total_intervals = 0
+    for f in files:
+        try:
+            r = read_idf_file(f)
+            ok += 1
+            total_intervals += len(r.intervals or [])
+        except NotImplementedError:
+            nyi += 1
+        except Exception as exc:
+            fail += 1
+            if fail <= 3:
+                print(f"  FAIL: {f.name}: {type(exc).__name__}: {exc}")
+    print(f"Corpus: {len(files)} IDFH files | ok={ok} fail={fail} nyi={nyi}")
+    print(f"Total intervals decoded: {total_intervals}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/smoke_test.py b/analysis_idf/smoke_test.py
new file mode 100644
index 0000000..a0be7c6
--- /dev/null
+++ b/analysis_idf/smoke_test.py
@@ -0,0 +1,48 @@
+"""Smoke-test read_idf_file across the sample corpus."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from micromate.idf_file import read_idf_file, geo_count_to_ips, mic_count_to_psi
+
+
+def main():
+    target = REPO / "tests/fixtures/THORDATA_example/THORDATA_example/UPMC Presby/UM11719/UM11719_20231219162723.IDFW"
+    result = read_idf_file(target)
+    ev = result.event
+    print(f"=== {target.name} ===")
+    print(f"  signature: {result.signature}")
+    print(f"  serial:    {ev.serial}")
+    print(f"  timestamp: {ev.timestamp}")
+    print(f"  sample_rate: {ev.sample_rate}")
+    print(f"  record_time: {ev.record_time_sec}")
+    print(f"  calibration: {result.binary_metadata.calibration_date}")
+    print(f"  Tran samples: {len(result.samples['Tran'])}, peak_ips={ev.peaks.transverse_ips:.4f}")
+    print(f"  Vert samples: {len(result.samples['Vert'])}, peak_ips={ev.peaks.vertical_ips:.4f}")
+    print(f"  Long samples: {len(result.samples['Long'])}, peak_ips={ev.peaks.longitudinal_ips:.4f}")
+    print(f"  MicL samples: {len(result.samples['MicL'])}")
+    print()
+
+    # Corpus sweep
+    root = REPO / "tests/fixtures/THORDATA_example"
+    files = [f for f in root.rglob("*.IDFW") if not str(f).endswith(".CDB")]
+    ok = fail = nyi = 0
+    for f in files:
+        try:
+            r = read_idf_file(f)
+            ok += 1
+        except NotImplementedError:
+            nyi += 1
+        except Exception as exc:
+            fail += 1
+            if fail <= 5:
+                print(f"  FAIL: {f.name}: {type(exc).__name__}: {exc}")
+    print()
+    print(f"Corpus: {len(files)} IDFW files | ok={ok} fail={fail} not-implemented={nyi}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/trace_path.py b/analysis_idf/trace_path.py
new file mode 100644
index 0000000..fb9fb04
--- /dev/null
+++ b/analysis_idf/trace_path.py
@@ -0,0 +1,73 @@
+"""Trace Tran sample-by-sample to find exactly where the codec drifts."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def s4(n: int) -> int:
+    return n if n < 8 else n - 16
+
+
+def i8(b: int) -> int:
+    return b if b < 128 else b - 256
+
+
+def main():
+    buf = TARGET.read_bytes()
+    sc = load_sidecar_samples(TXT)
+    GEO_LSB = 0.0003
+    sc_tran = [int(round(v / GEO_LSB)) for v in sc["Tran"]]
+
+    body = buf[0x0f1f:]
+    # Tran[0], Tran[1] from preamble
+    t0 = int.from_bytes(body[3:5], "big", signed=True)
+    t1 = int.from_bytes(body[5:7], "big", signed=True)
+    print(f"preamble Tran[0]={t0}  Tran[1]={t1}  (sidecar: {sc_tran[0]}, {sc_tran[1]})")
+
+    # Block 0: 10 f8 at body[7:9]
+    print(f"block 0: tag {body[7]:02x} {body[8]:02x}")
+    print(f"  block 0 first 10 data bytes: {body[9:19].hex()}")
+
+    # Walk block 0 manually, comparing each sample
+    cur = t1
+    samples = [t0, t1]
+    block_off = 7
+    nn = body[8]
+    print(f"  NN = {nn}")
+    data = body[9 : 9 + nn // 2]
+    for byi, byte in enumerate(data):
+        for nib_idx, nib in enumerate(((byte >> 4) & 0xF, byte & 0xF)):
+            cur += s4(nib)
+            samples.append(cur)
+            idx = len(samples) - 1
+            if 0 <= idx < len(sc_tran):
+                sc_v = sc_tran[idx]
+                match = "✓" if sc_v == cur else "✗"
+                if idx < 12 or 240 <= idx <= 260:
+                    print(f"    idx {idx:3d}: nibble byte={byte:02x} nib={nib:x} delta={s4(nib):+d}  cur={cur:+d}  sc={sc_v:+d}  {match}")
+
+    print(f"end of block 0: cur={cur}, len(samples)={len(samples)}, decoder expected 250 here")
+    # Block 1: 20 28 starts at offset 9 + 124 = 133 from block_off=7
+    block1_off = 9 + nn // 2
+    print(f"block 1: tag {body[block1_off]:02x} {body[block1_off+1]:02x} (expecting 20 28)")
+    nn1 = body[block1_off + 1]
+    print(f"  block 1 NN = {nn1}")
+    data1 = body[block1_off + 2 : block1_off + 2 + nn1]
+    for byi, byte in enumerate(data1):
+        cur += i8(byte)
+        samples.append(cur)
+        idx = len(samples) - 1
+        if idx < len(sc_tran):
+            sc_v = sc_tran[idx]
+            match = "✓" if sc_v == cur else "✗"
+            if 248 <= idx <= 295:
+                print(f"    idx {idx:3d}: int8 byte={byte:02x} delta={i8(byte):+d}  cur={cur:+d}  sc={sc_v:+d}  {match}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/try_codec.py b/analysis_idf/try_codec.py
new file mode 100644
index 0000000..e0f5269
--- /dev/null
+++ b/analysis_idf/try_codec.py
@@ -0,0 +1,42 @@
+"""Feed candidate body offsets to the BW codec and compare with sidecar."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import decode_waveform_v2, walk_body, find_data_start
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    sc = load_sidecar_samples(TXT)
+    # Sidecar samples in 0.0003 counts (Thor geo LSB).
+    sc_tran = [int(round(v / 0.0003)) for v in sc["Tran"][:30]]
+    sc_vert = [int(round(v / 0.0003)) for v in sc["Vert"][:30]]
+    sc_long = [int(round(v / 0.0003)) for v in sc["Long"][:30]]
+    sc_micl = [int(round(v / 1e-6)) for v in sc["MicL"][:30]]  # 1 µ unit for mic? Will iterate.
+    print(f"sidecar Tran (counts): {sc_tran}")
+    print(f"sidecar Vert (counts): {sc_vert}")
+    print(f"sidecar Long (counts): {sc_long}")
+    print(f"sidecar MicL (×1e-6):  {sc_micl}")
+    print()
+
+    # Try candidate body start offsets.
+    for off in (0x0f1f, 0x1057, 0x11f1, 0x1333, 0x1bde, 0x0d30):
+        print(f"=== body @ 0x{off:04x} ===")
+        body = buf[off:]
+        decoded = decode_waveform_v2(body)
+        if not decoded:
+            print("  decode_waveform_v2 returned None")
+            continue
+        for ch in ("Tran", "Vert", "Long", "MicL"):
+            arr = decoded.get(ch, [])
+            print(f"  {ch}[{len(arr)}]: {arr[:20]}")
+        print()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/analysis_idf/verify_full.py b/analysis_idf/verify_full.py
new file mode 100644
index 0000000..ebc8b49
--- /dev/null
+++ b/analysis_idf/verify_full.py
@@ -0,0 +1,51 @@
+"""Verify decode_waveform_v2 against sidecar across all 2304 samples per channel."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import decode_waveform_v2
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    sc = load_sidecar_samples(TXT)
+    body = buf[0x0f1f:]
+    decoded = decode_waveform_v2(body)
+
+    print(f"Sidecar lengths: Tran={len(sc['Tran'])} Vert={len(sc['Vert'])} Long={len(sc['Long'])} MicL={len(sc['MicL'])}")
+    print(f"Decoded lengths: Tran={len(decoded['Tran'])} Vert={len(decoded['Vert'])} Long={len(decoded['Long'])} MicL={len(decoded['MicL'])}")
+    print()
+
+    GEO_LSB = 0.0003  # in/s per count
+    for ch in ("Tran", "Vert", "Long"):
+        sc_counts = [int(round(v / GEO_LSB)) for v in sc[ch]]
+        dec = decoded[ch]
+        n = min(len(sc_counts), len(dec))
+        matches = sum(1 for i in range(n) if sc_counts[i] == dec[i])
+        first_mismatch = next((i for i in range(n) if sc_counts[i] != dec[i]), None)
+        print(f"{ch}: compared {n}, exact matches {matches} ({100*matches/n:.2f}%)")
+        if first_mismatch is not None:
+            i = first_mismatch
+            print(f"  first mismatch at idx {i}: sidecar={sc_counts[i]} ({sc[ch][i]}), decoded={dec[i]}")
+            print(f"  context sidecar[{i-2}..{i+5}]: {sc_counts[max(0,i-2):i+5]}")
+            print(f"  context decoded[{i-2}..{i+5}]: {dec[max(0,i-2):i+5]}")
+
+    # MicL: find the multiplicative factor that fits
+    print()
+    print("=== MicL scale analysis ===")
+    sc_micl = sc["MicL"]
+    dec_micl = decoded["MicL"]
+    # Skip zero values when computing ratio
+    ratios = [sc_micl[i] / dec_micl[i] for i in range(min(50, len(sc_micl), len(dec_micl))) if dec_micl[i] != 0]
+    if ratios:
+        avg = sum(ratios) / len(ratios)
+        print(f"  avg ratio sidecar/decoded over first 50 nonzero: {avg:.4e} (n={len(ratios)})")
+        print(f"  ratios sample: {[f'{r:.4e}' for r in ratios[:6]]}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/docs/idf_protocol_reference.md b/docs/idf_protocol_reference.md
index 643de53..aef3c69 100644
--- a/docs/idf_protocol_reference.md
+++ b/docs/idf_protocol_reference.md
@@ -6,11 +6,68 @@ Series IV event-file format.  Sibling to
 Series III "Rosetta Stone") — this doc holds what we know so far and
 the open questions still to crack.
 
-**Status (2026-05-20):** ASCII text sidecar fully decoded (1,014
-sample files round-trip).  Binary `.IDFH` / `.IDFW` codec
-**not yet implemented** — binaries are stored opaquely by
-`WaveformStore.save_imported_idf`, with metadata sourced from the
-paired `.txt` sidecar.
+**Status (2026-05-28):** ASCII text sidecar fully decoded (1,014
+sample files round-trip).  **Thor IDFW** binary now decodes via
+`micromate.idf_file.read_idf_file()` — reuses the BW segment-rotated
+block codec verbatim at fixed body offset `0x0f1f`; metadata (serial,
+timestamp, sample_rate, record_time, calibration_date) extracted from
+the binary header.  Sample fidelity is 87–99% byte-exact on quiet
+events; loud events hit the BW codec's known walker-stops-early
+limitation.  Residual ~3% drift on per-sample deltas (likely a
+Thor-specific 12-bit delta refinement not yet modelled).
+
+**Thor IDFH histograms also decoded.**  Body has one or more segments;
+each 12-byte segment header `[length_be 2B][0a 00 00 00][00 NN][05 3f]`
+introduces `N = (length - 10) // 72` interval records of 72 bytes
+each.  Each interval = 4 × 16-byte per-channel records:
+`[int16 min][int16 max][int16 ??][uint16 halfp][2B 00][uint16 ??][2B 00][uint16 ??]`.
+Geo peak `= max(|min|, |max|) / 32768 × 10` in/s (matches sidecar
+~1.8%); freq `= 512 / halfp` Hz (None for halfp ≤ 5 → ">100"
+sentinel).  Corpus: **all 859 Thor IDFH files decode, 181,071
+intervals**.  Wired through `read_idf_file()` →
+`save_imported_idf()` → sidecar's `extensions.idf_intervals`.
+
+**Note on the BE9439 outliers in the example corpus:** Two files
+(`BE9439_20200713131747.IDFW` and `BE9439_20200713124251.IDFH`) are
+**Series III Blastware** binaries, not Thor.  Provenance: TMI tried
+to use Thor to manage auto-call-homes for Series III units; the
+experiment didn't work out, but it did leave a few BW event files
+in Thor's per-serial directory structure with `.IDFW`/`.IDFH`
+extensions — Thor's forwarder applied its own naming convention to
+the BW bodies it was relaying.  Their header `10 00 01 80 00 00
+Instantel STRT ff fe <end_key> <start_key>` is the BW SUB 5A STRT
+record, not a Thor body preamble.  The reader detects them by
+signature and raises `NotImplementedError` pointing callers at
+`read_blastware_file()`, which extracts BW-format peaks from them.
+
+**Still NYI for Thor IDFH:** per-channel `int16 field4` (possibly
+time-of-peak); the two uint16 fields (probably PVS contributions);
+8-byte interval tail (PVS data); mic dB(L) exact conversion constant.
+
+### Codec breakthroughs (2026-05-28)
+
+- **Body offset is a fixed `0x0f1f`** across 151/154 corpus IDFW
+  files.  Preceded by a 4-byte record-type marker (`46 00 00 00`)
+  + magic preamble `00 02 00 [Tran[0] BE] [Tran[1] BE]`.
+- **Sample stream is BW's segment-rotated block codec verbatim.**
+  Thor reuses `10 NN` (nibble), `20 NN` (int8), `00 NN` (RLE),
+  `30 NN` (packed12), `40 02` (segment header) tags with the same
+  semantics.  Channel rotation Tran→Vert→Long→MicL.
+- **Geo LSB = 0.0003 in/s** (not BW's 0.005), because Thor's 16-bit
+  ADC range maps to 10 in/s without the 16-count BW quantization step.
+- **Mic ≈ 2.14×10⁻⁶ psi/count** (rough scale; refine after channel
+  block calibration constants are decoded).
+- **BW compliance anchor `\xbe\x80\x00\x00\x00\x00` reappears at
+  IDFW offset 0x952** — sample_rate at anchor−6 (uint16 BE),
+  record_time at anchor+6 (float32 BE), same layout as BW.
+- **Event timestamp at offset 0x97A** — 8 bytes `[day][month]
+  [year_be][unk][hour][min][sec]`.  Stop-time mirrors at 0x982.
+- **Serial as null-terminated ASCII at 0x14E**.
+- **Calibration date** at 0x194–0x197 (day, month, year_be).
+- Per-sample residual drift of ~3% suggests Thor encodes int8/nibble
+  deltas with an extra refinement bit that BW doesn't carry —
+  unsolved; errors resync within a few samples so cumulative impact
+  is small.
 
 ---
 
diff --git a/micromate/idf_file.py b/micromate/idf_file.py
index b3cd669..bee7555 100644
--- a/micromate/idf_file.py
+++ b/micromate/idf_file.py
@@ -1,64 +1,450 @@
 """
-micromate/idf_file.py — placeholder for the Thor IDF binary codec.
+micromate/idf_file.py — Thor IDF binary codec.
 
-Thor's ``.IDFH`` (histogram) and ``.IDFW`` (waveform) event files are an
-Instantel proprietary binary format that has not yet been reverse-
-engineered.  Today seismo-relay treats them as opaque blobs:
-``WaveformStore.save_imported_idf`` stores the bytes verbatim and reads
-all device-authoritative metadata from the paired ``.IDFW.txt`` /
-``.IDFH.txt`` ASCII sidecar (parsed by ``idf_ascii_report.py``).
+Decodes the Instantel Micromate Series IV ``.IDFW`` (waveform) and
+``.IDFH`` (histogram) binary on-disk format.  Sister module to
+``minimateplus/event_file_io.py``.
 
-When we crack the binary codec — same reverse-engineering playbook we
-used to byte-perfect-parse Series III BW files (see
-``docs/instantel_protocol_reference.md`` and ``minimateplus/event_file_io.py``)
-— this module will grow:
+Status (2026-05-28):
 
-  - ``read_idf_file(path) -> IdfEvent``
-        Parse a ``.IDFW``/``.IDFH`` binary and return a fully populated
-        ``IdfEvent`` whose waveform-sample arrays come from the binary
-        (the .txt sidecar's tabular sample block being a best-effort
-        check).  Lets us ingest Thor events even when the operator
-        hasn't enabled the .txt exporter — closing the
-        ``had_report=False`` gap that the thor-watcher forwarder
-        currently tolerates as a known limitation.
+- **Genuine Series IV / Thor binaries** are all signed
+  ``00 12 01 00 00 00 Instantel\\0`` (sig-A in earlier notes).  Two
+  Series III (Blastware) binaries appear in the example corpus
+  (``BE9439_*``) — they share the ``.IDFW``/``.IDFH`` extension by
+  filing convention but carry a BW STRT header (``10 00 01 80 00 00
+  Instantel STRT...``) and are NOT Thor data.  The reader detects
+  them by signature and raises NotImplementedError pointing callers
+  at ``minimateplus.event_file_io.read_blastware_file()``.
+- **IDFW waveform body** reuses the BW segment-rotated block codec
+  verbatim.  Body always starts at file offset ``0x0f1f``.  Samples
+  decoded via ``minimateplus.waveform_codec.decode_waveform_v2``
+  with 87–99% byte-exact match against ``.IDFW.txt`` sidecar (quiet
+  events).  Loud events hit the BW codec's known walker-stops-early
+  limit.  Residual ~3% drift on per-sample deltas — likely a
+  Thor-specific 12-bit delta refinement that BW's codec doesn't
+  model.  Geo LSB = 0.0003 in/s; mic factor ~2.14e-6 psi/count.
+- **IDFH histogram body**: 12-byte segment header
+  ``[len_be 2B] 0a 00 00 00 [00 NN_counter] 05 3f`` introduces a
+  segment of ``N`` 72-byte interval records (``N = (len - 10) // 72``).
+  Each record holds 4 × 16-byte per-channel min/max/halfp + 8-byte
+  tail.  Geo peaks via ``max(|min|, |max|) / 32768 × 10`` in/s
+  (matches sidecar within ~1.8%), freq via ``512 / halfp`` Hz.
+  **All 859 Thor IDFH files in the corpus decode (181,071 intervals).**
+- Binary metadata directly extracted: serial, timestamp, sample_rate,
+  record_time, calibration_date.  Other fields fall back to the paired
+  ``.IDFW.txt`` / ``.IDFH.txt`` sidecar (consumed by
+  ``WaveformStore.save_imported_idf``).
 
-  - ``write_idf_file(path, event)`` (eventually)
-        Round-trip event reconstruction, used for verifying the codec
-        against captured device files the way ``write_blastware_file``
-        verifies the Series III codec.
-
-  - Helpers for decoding the binary's per-channel sample arrays into
-    physical units, the per-event flash buffer's monitor-log records,
-    etc.
-
-The reverse-engineering path: pair every ``.IDFW`` binary in
-``thor-watcher/example-data/`` with its sibling ``.IDFW.txt``, treating
-the txt's "Waveform Data Channels" block as ground-truth, and align
-the binary's per-channel int16-or-similar arrays against it.  Header
-fields (sample rate, channel count, record time, timestamps) sit before
-the sample block — same approach as the BW codec where ASCII strings
-inside the binary (``Project:``, ``Client:``, etc.) anchored field
-discovery.
+The full reverse-engineering writeup lives in
+``docs/idf_protocol_reference.md``.
 """
 
 from __future__ import annotations
 
+import datetime
+import struct
+from dataclasses import dataclass
 from pathlib import Path
-from typing import Union
+from typing import Optional, Union
 
-from .models import IdfEvent
+from minimateplus.waveform_codec import decode_waveform_v2
+
+from .models import IdfEvent, IdfPeaks, IdfReport
 
 
-def read_idf_file(path: Union[str, Path]) -> "IdfEvent":
-    """Parse a Thor ``.IDFW``/``.IDFH`` binary into an ``IdfEvent``.
+# Genuine Series IV / Thor IDF binary signature: 6 bytes, then ASCII "Instantel".
+_THOR_PREFIX = b"\x00\x12\x01\x00\x00\x00"
+# Stray Series III (Blastware) binaries that occasionally turn up in Thor
+# corpus directories renamed to the .IDFW/.IDFH convention.  Their header
+# (`10 00 01 80 00 00 Instantel STRT ...`) is byte-for-byte a BW SUB 5A
+# STRT record, not a Thor binary.  Detected so we can refuse-and-route
+# rather than mis-parse.
+_BW_STRAY_PREFIX = b"\x10\x00\x01\x80\x00\x00"
+_INSTANTEL_TAG = b"Instantel"
 
-    Not yet implemented.  When implemented, this will be the canonical
-    entry point for reading Thor binaries — the ASCII sidecar parser
-    becomes an optional fast-path metadata supplement rather than the
-    sole source of device-authoritative data.
+# Constant body offset for sig-A IDFW files (verified across 151/154 corpus
+# files in tests/fixtures/THORDATA_example).  The body is the segment-rotated
+# block stream consumed by decode_waveform_v2; bytes [0:3] are the magic
+# ``00 02 00`` preamble.
+_BODY_START_SIG_A = 0x0F1F
+
+# Geophone count → in/s, derived from sidecar ground truth: the smallest
+# non-zero sample in 1,014-file corpus is 0.0003 in/s.
+_GEO_LSB_IPS = 0.0003
+
+# Microphone count → psi, derived from sidecar regression on 50 sample
+# pairs from UM11719_20231219162723.IDFW (mic-heavy event).
+_MIC_LSB_PSI = 2.14e-6
+
+# IDFH histogram constants.
+_IDFH_INTERVAL_SIZE = 72        # bytes per per-interval record
+_IDFH_SEGMENT_HEADER = 10       # bytes: [len_be 2B][0a 00 00 00 4B][00 NN 2B][05 3f 2B]
+_IDFH_SEGMENT_TAIL   = 2        # bytes after the interval data block, before next marker
+_IDFH_HALFP_FREQ_NUM = 512.0    # freq_hz = NUM / halfp; halfp ≤ 5 means ">100 Hz" sentinel
+_IDFH_GEO_FULL_SCALE = 10.0     # in/s — Normal range
+_IDFH_INT16_FS = 32768.0
+_IDFH_CHANNELS = ("Tran", "Vert", "Long", "MicL")
+
+
+# ─── Binary metadata extraction ─────────────────────────────────────────────
+
+
+@dataclass
+class IdfBinaryMetadata:
+    """Fields recoverable from the sig-A binary header (no .txt needed)."""
+    serial:           Optional[str] = None
+    event_datetime:   Optional[datetime.datetime] = None
+    sample_rate:      Optional[int] = None
+    record_time_sec:  Optional[float] = None
+    calibration_date: Optional[datetime.date] = None
+
+
+def _read_ascii_z(buf: bytes, off: int, maxlen: int = 64) -> Optional[str]:
+    if off >= len(buf):
+        return None
+    end = buf.find(b"\x00", off, off + maxlen)
+    if end < 0:
+        end = min(off + maxlen, len(buf))
+    s = buf[off:end].decode("ascii", errors="replace").strip()
+    return s or None
+
+
+def _decode_8byte_timestamp(buf: bytes, off: int) -> Optional[datetime.datetime]:
+    """Layout: ``[day][month][year_hi][year_lo][unknown][hour][min][sec]``."""
+    if off + 8 > len(buf):
+        return None
+    day, mon, yh, yl, _unk, hr, mn, sc = buf[off : off + 8]
+    year = (yh << 8) | yl
+    if not (2015 <= year <= 2050 and 1 <= mon <= 12 and 1 <= day <= 31
+            and 0 <= hr < 24 and 0 <= mn < 60 and 0 <= sc < 60):
+        return None
+    try:
+        return datetime.datetime(year, mon, day, hr, mn, sc)
+    except ValueError:
+        return None
+
+
+def extract_binary_metadata(buf: bytes) -> IdfBinaryMetadata:
+    """Pull serial/timestamp/sample_rate/record_time/calibration from the
+    sig-A binary header.
+
+    Field positions confirmed against UM11719_20231219162723.IDFW; stable
+    across the 151-file sig-A corpus.
     """
-    raise NotImplementedError(
-        "IDF binary codec not yet implemented; the .IDFW/.IDFH binary format "
-        "is undecoded.  Use parse_idf_report() on the paired .txt sidecar "
-        "for device-authoritative metadata."
+    md = IdfBinaryMetadata()
+
+    # Serial: null-terminated ASCII at 0x14E.
+    md.serial = _read_ascii_z(buf, 0x14E, maxlen=16)
+
+    # Sample rate + record time live in a BW-compatible compliance block.
+    # Locate the 6-byte anchor `be 80 00 00 00 00` and read offsets relative
+    # to it: anchor-6 = sample_rate uint16 BE; anchor+6 = record_time float32 BE.
+    anchor = buf.find(b"\xbe\x80\x00\x00\x00\x00", 0x800, 0xA00)
+    if anchor > 0:
+        sr_bytes = buf[anchor - 6 : anchor - 4]
+        if len(sr_bytes) == 2:
+            sr = int.from_bytes(sr_bytes, "big")
+            if sr in (256, 512, 1024, 2048, 4096):
+                md.sample_rate = sr
+        rt_bytes = buf[anchor + 6 : anchor + 10]
+        if len(rt_bytes) == 4:
+            try:
+                rt = struct.unpack(">f", rt_bytes)[0]
+                if 0.1 <= rt <= 600.0:
+                    md.record_time_sec = float(rt)
+            except struct.error:
+                pass
+
+    # Event timestamp: 8 bytes.  Position differs between IDFW (0x97A) and
+    # IDFH (0x9F8); scan a small range and accept the first valid decode.
+    for off in (0x97A, 0x9F8):
+        ts = _decode_8byte_timestamp(buf, off)
+        if ts is not None:
+            md.event_datetime = ts
+            break
+
+    # Calibration date: day, month, year_be at 0x194-0x197.
+    if len(buf) > 0x197:
+        day, mon = buf[0x194], buf[0x195]
+        year = int.from_bytes(buf[0x196 : 0x198], "big")
+        if 1 <= mon <= 12 and 1 <= day <= 31 and 2015 <= year <= 2050:
+            try:
+                md.calibration_date = datetime.date(year, mon, day)
+            except ValueError:
+                pass
+
+    return md
+
+
+# ─── Sample decoder + unit conversion ───────────────────────────────────────
+
+
+def _decode_waveform_samples(buf: bytes) -> Optional[dict]:
+    """Decode samples from the sig-A body starting at file offset 0x0f1f.
+
+    Returns the raw decoder counts dict — geo LSB = 0.0003 in/s, mic in
+    its own count unit (see :func:`mic_count_to_psi`).  Returns None if
+    decoding fails.
+    """
+    if len(buf) < _BODY_START_SIG_A + 8:
+        return None
+    body = buf[_BODY_START_SIG_A:]
+    return decode_waveform_v2(body)
+
+
+def geo_count_to_ips(count: int) -> float:
+    """Convert a Thor geo decoder count to in/s.  LSB = 0.0003 in/s."""
+    return count * _GEO_LSB_IPS
+
+
+def mic_count_to_psi(count: int) -> float:
+    """Convert a Thor mic decoder count to psi.  Scale derived from
+    regression over 50 sample pairs in UM11719_20231219162723.IDFW;
+    consistent to ~5%.  Calibration constants from the channel block
+    can refine this once decoded.
+    """
+    return count * _MIC_LSB_PSI
+
+
+# ─── IDFH histogram decoder ─────────────────────────────────────────────────
+
+
+@dataclass
+class IdfhInterval:
+    """One decoded histogram interval (typically one minute of monitoring)."""
+    offset:    int    # file byte offset of the 72-byte record
+    # Per-channel min/max ADC counts (int16 BE), half-period samples, peak count.
+    # Peak = max(|min|, |max|).  freq_hz = 512/halfp (None if halfp ≤ 5 →
+    # ">100 Hz" sentinel; matches sidecar convention).
+    tran_min:    int
+    tran_max:    int
+    tran_halfp:  int
+    vert_min:    int
+    vert_max:    int
+    vert_halfp:  int
+    long_min:    int
+    long_max:    int
+    long_halfp:  int
+    micl_min:    int
+    micl_max:    int
+    micl_halfp:  int
+
+    def peak_count(self, channel: str) -> int:
+        mn = getattr(self, f"{channel.lower()}_min")
+        mx = getattr(self, f"{channel.lower()}_max")
+        return max(abs(mn), abs(mx))
+
+    def peak_ips(self, channel: str) -> float:
+        """Convert peak count to in/s (geo channels only)."""
+        return self.peak_count(channel) / _IDFH_INT16_FS * _IDFH_GEO_FULL_SCALE
+
+    def freq_hz(self, channel: str) -> Optional[float]:
+        halfp = getattr(self, f"{channel.lower()}_halfp")
+        if halfp <= 5:
+            return None
+        return _IDFH_HALFP_FREQ_NUM / halfp
+
+
+def _decode_idfh_interval(buf72: bytes, offset: int) -> IdfhInterval:
+    """Decode one 72-byte interval record into per-channel min/max/halfp."""
+    import struct
+    fields = []
+    for i in range(4):
+        block = buf72[i * 16 : (i + 1) * 16]
+        mn = struct.unpack_from(">h", block, 0)[0]
+        mx = struct.unpack_from(">h", block, 2)[0]
+        # block[4:6] = int16 BE, role unknown (possibly time-of-peak)
+        halfp = struct.unpack_from(">H", block, 6)[0]
+        # block[10:12] and block[14:16] are uint16 BE with unknown semantics
+        # (likely sum / count contributions for the PVS computation).
+        fields.extend([mn, mx, halfp])
+    # Tail 8 bytes (buf72[64:72]) carry PVS-related data; not yet decoded.
+    return IdfhInterval(
+        offset=offset,
+        tran_min=fields[0], tran_max=fields[1], tran_halfp=fields[2],
+        vert_min=fields[3], vert_max=fields[4], vert_halfp=fields[5],
+        long_min=fields[6], long_max=fields[7], long_halfp=fields[8],
+        micl_min=fields[9], micl_max=fields[10], micl_halfp=fields[11],
+    )
+
+
+def decode_idfh_body(buf: bytes) -> list:
+    """Walk an IDFH file and decode every interval record.
+
+    The body has one or more segments; each segment header is 12 bytes:
+    ``[length_be 2B][0a 00 00 00][00 NN_counter][05 3f]`` where ``length``
+    is bytes from the magic through the end of the interval block
+    (= 10 + 72 × n_intervals).  Segments are separated by a 2-byte tail
+    + next-segment 2-byte prefix (the bytes before the next length field).
+    Confirmed against the 859-file corpus (181,071 intervals decoded; 1
+    failure is the sig-B BE9439 file).
+    """
+    intervals: list = []
+    i = 0
+    while True:
+        j = buf.find(b"\x0a\x00\x00\x00", i)
+        if j < 0 or j < 2:
+            break
+        # Validate: [length_be][0a 00 00 00][00 NN][05 3f]
+        if buf[j + 4] != 0x00 or buf[j + 6 : j + 8] != b"\x05\x3f":
+            i = j + 1
+            continue
+        length = int.from_bytes(buf[j - 2 : j], "big")
+        n = (length - _IDFH_SEGMENT_HEADER) // _IDFH_INTERVAL_SIZE
+        if n <= 0:
+            i = j + 1
+            continue
+        header_start = j - 2
+        interval_start = header_start + _IDFH_SEGMENT_HEADER
+        for k in range(n):
+            off = interval_start + k * _IDFH_INTERVAL_SIZE
+            if off + _IDFH_INTERVAL_SIZE > len(buf):
+                break
+            chunk = buf[off : off + _IDFH_INTERVAL_SIZE]
+            intervals.append(_decode_idfh_interval(chunk, off))
+        # Advance past this segment + the 2-byte tail.
+        i = header_start + length + _IDFH_SEGMENT_TAIL
+    return intervals
+
+
+# ─── Top-level reader ───────────────────────────────────────────────────────
+
+
+@dataclass
+class IdfReadResult:
+    """Return type for :func:`read_idf_file`.
+
+    For waveforms (``.IDFW``), ``samples`` holds the per-channel sample
+    arrays in Thor decoder counts.  For histograms (``.IDFH``),
+    ``samples`` is empty and ``intervals`` holds the per-interval
+    record list (peaks, freqs).
+    """
+    event:           IdfEvent
+    samples:         dict   # {"Tran": [...], ...} for IDFW; empty for IDFH
+    binary_metadata: IdfBinaryMetadata
+    signature:       str    # always "thor" for now (sig-A genuine Thor)
+    intervals:       Optional[list] = None  # list[IdfhInterval] for IDFH; None for IDFW
+
+
+def read_idf_file(path: Union[str, Path]) -> IdfReadResult:
+    """Parse a Thor ``.IDFW`` binary into an ``IdfEvent`` + decoded samples.
+
+    Currently implements signature-A waveforms only.  Signature-B
+    (old-firmware) and ``.IDFH`` histograms raise NotImplementedError;
+    use the paired ``.IDFW.txt`` / ``.IDFH.txt`` sidecar for those via
+    ``parse_idf_report()``.
+
+    Returns an :class:`IdfReadResult`.  The caller converts int sample
+    counts to physical units via :func:`geo_count_to_ips` /
+    :func:`mic_count_to_psi`.
+    """
+    p = Path(path)
+    buf = p.read_bytes()
+
+    if len(buf) < 16 or buf[6:16] != _INSTANTEL_TAG + b"\x00":
+        raise ValueError(f"{p.name}: not an IDF file (missing Instantel magic)")
+
+    sig_prefix = buf[:6]
+    if sig_prefix == _THOR_PREFIX:
+        signature = "thor"
+    elif sig_prefix == _BW_STRAY_PREFIX:
+        raise NotImplementedError(
+            f"{p.name}: file has a Series III (Blastware) STRT header in "
+            "an IDF-named container — not a Thor binary.  Route through "
+            "minimateplus.event_file_io.read_blastware_file() instead "
+            "(peaks decode; samples & full metadata don't, but it's not "
+            "Thor data so the Thor codec doesn't apply)."
+        )
+    else:
+        raise ValueError(f"{p.name}: unknown IDF signature {sig_prefix.hex()}")
+
+    is_histogram = p.suffix.upper() == ".IDFH"
+    md = extract_binary_metadata(buf)
+
+    if is_histogram:
+        intervals = decode_idfh_body(buf)
+        if not intervals:
+            raise ValueError(f"{p.name}: IDFH body decoded no intervals")
+        # Peaks: max across all intervals on each channel (per-channel max
+        # of stored max-magnitudes; sidecar's PPV row carries the same).
+        peak_tran = max((iv.peak_ips("Tran") for iv in intervals), default=0.0)
+        peak_vert = max((iv.peak_ips("Vert") for iv in intervals), default=0.0)
+        peak_long = max((iv.peak_ips("Long") for iv in intervals), default=0.0)
+        rep = IdfReport(
+            serial_number=md.serial,
+            event_type="Full Histogram",
+            event_datetime=md.event_datetime,
+            filename=p.name,
+            sample_rate=md.sample_rate,
+            record_time_sec=md.record_time_sec,
+        )
+        peaks = IdfPeaks(
+            transverse_ips=peak_tran,
+            vertical_ips=peak_vert,
+            longitudinal_ips=peak_long,
+            peak_vector_sum_ips=None,
+            mic_pspl_dbl=None,
+        )
+        event = IdfEvent(
+            serial=md.serial or "UNKNOWN",
+            timestamp=md.event_datetime or datetime.datetime(1970, 1, 1),
+            kind="Histogram",
+            filename=p.name,
+            sample_rate=md.sample_rate,
+            record_time_sec=md.record_time_sec,
+            peaks=peaks,
+            report=rep,
+        )
+        return IdfReadResult(
+            event=event,
+            samples={},
+            binary_metadata=md,
+            signature=signature,
+            intervals=intervals,
+        )
+
+    # Waveform path.
+    decoded = _decode_waveform_samples(buf)
+    if decoded is None:
+        raise ValueError(f"{p.name}: waveform body codec failed")
+
+    rep = IdfReport(
+        serial_number=md.serial,
+        event_type="Full Waveform",
+        event_datetime=md.event_datetime,
+        filename=p.name,
+        sample_rate=md.sample_rate,
+        record_time_sec=md.record_time_sec,
+    )
+
+    def _peak_ips(ch: str) -> float:
+        arr = decoded.get(ch, [])
+        return geo_count_to_ips(max((abs(v) for v in arr), default=0))
+
+    peaks = IdfPeaks(
+        transverse_ips=_peak_ips("Tran"),
+        vertical_ips=_peak_ips("Vert"),
+        longitudinal_ips=_peak_ips("Long"),
+        # PVS requires aligned per-sample √(T²+V²+L²); leave None — the
+        # sidecar carries it and the bridge picks it up if present.
+        peak_vector_sum_ips=None,
+        mic_pspl_dbl=None,
+    )
+
+    event = IdfEvent(
+        serial=md.serial or "UNKNOWN",
+        timestamp=md.event_datetime or datetime.datetime(1970, 1, 1),
+        kind="Waveform",
+        filename=p.name,
+        sample_rate=md.sample_rate,
+        record_time_sec=md.record_time_sec,
+        peaks=peaks,
+        report=rep,
+    )
+
+    return IdfReadResult(
+        event=event,
+        samples=decoded,
+        binary_metadata=md,
+        signature=signature,
     )
diff --git a/sfm/waveform_store.py b/sfm/waveform_store.py
index d982dce..031a9c0 100644
--- a/sfm/waveform_store.py
+++ b/sfm/waveform_store.py
@@ -467,21 +467,21 @@ class WaveformStore:
         Ingest a Thor (Micromate Series IV) IDF event file (`.IDFW` or
         `.IDFH`) produced by Thor's TXT exporter.
 
-        Thor binaries are stored as opaque bytes — seismo-relay doesn't
-        yet decode the proprietary IDF binary format (codec slot lives
-        at ``micromate/idf_file.py``).  Device-authoritative metadata
-        comes from the paired ``.IDFW.txt`` / ``.IDFH.txt`` sidecar
-        when supplied.
-
         Workflow:
-          1. Parse the paired TXT report (when supplied) via
-             ``micromate.parse_idf_report`` → dict.
-          2. Wrap parsed dict + filename into a typed ``micromate.IdfEvent``.
-          3. Copy bytes verbatim into ``<root>/<serial>/<filename>``.
-          4. Bridge IdfEvent → ``minimateplus.Event`` (for the existing
-             sidecar / DB insert machinery) via
-             ``IdfEvent.to_minimateplus_event(waveform_key)``.
-          5. Write the ``.sfm.json`` sidecar with
+          1. For sig-A `.IDFW` binaries, decode samples + binary metadata
+             via ``micromate.idf_file.read_idf_file()``.  Failure or
+             non-IDFW path falls through to the .txt-only flow.
+          2. Parse the paired TXT report (when supplied) via
+             ``micromate.parse_idf_report`` → dict.  TXT remains the
+             source of truth for fields the binary doesn't yet supply
+             (full peak set with ZC freq / Time of Peak, sensor self-check,
+             firmware string, project strings).
+          3. Wrap parsed dict + filename into a typed ``micromate.IdfEvent``.
+          4. Copy bytes verbatim into ``<root>/<serial>/<filename>``.
+          5. Bridge IdfEvent → ``minimateplus.Event`` and attach
+             ``raw_samples`` from the binary decoder (when available).
+          6. Write the `.h5` clean-waveform file when samples decoded.
+          7. Write the ``.sfm.json`` sidecar with
              ``source.kind = "idf-import"`` and the full raw IDF report
              under ``extensions.idf_report``.
 
@@ -490,7 +490,33 @@ class WaveformStore:
         """
         from micromate import IdfEvent, parse_idf_report
 
-        # Parse the .txt sidecar (best-effort; non-fatal on failure).
+        # 1. Binary decode (sig-A IDFW and IDFH).  Non-fatal: any failure
+        # leaves samples / binary metadata unfilled and we proceed with
+        # the .txt path as before.
+        idf_samples: Optional[dict] = None
+        idf_intervals: Optional[list] = None
+        binary_md = None
+        binary_peaks = None
+        is_histogram = False
+        try:
+            from micromate.idf_file import read_idf_file
+            res = read_idf_file(source_path)
+            idf_samples = res.samples or None
+            idf_intervals = res.intervals
+            is_histogram = res.intervals is not None
+            binary_md = res.binary_metadata
+            binary_peaks = res.event.peaks
+        except NotImplementedError:
+            # sig-B — codec doesn't handle this yet.
+            pass
+        except Exception as exc:
+            log.warning(
+                "save_imported_idf: binary codec failed for %s: %s — "
+                "falling back to .txt-only ingest",
+                source_path.name, exc,
+            )
+
+        # 2. Parse the .txt sidecar (best-effort; non-fatal on failure).
         report_dict: dict = {}
         if idf_report_text is not None:
             try:
@@ -501,7 +527,38 @@ class WaveformStore:
                     exc,
                 )
 
-        # Build the typed IdfEvent.  Filename is authoritative for
+        # 3. Backfill report_dict with binary metadata for fields the
+        # .txt didn't supply.  Binary takes precedence on tied fields
+        # where the binary is more reliable (timestamp, sample_rate),
+        # and fills in fields entirely missing from the .txt.
+        if binary_md is not None:
+            if binary_md.serial and not report_dict.get("serial_number"):
+                report_dict["serial_number"] = binary_md.serial
+            if binary_md.event_datetime and not report_dict.get("event_datetime"):
+                report_dict["event_datetime"] = binary_md.event_datetime
+            if binary_md.sample_rate and not report_dict.get("sample_rate"):
+                report_dict["sample_rate"] = binary_md.sample_rate
+            if binary_md.record_time_sec and not report_dict.get("record_time_sec"):
+                report_dict["record_time_sec"] = binary_md.record_time_sec
+            # Calibration date (binary) vs calibration text (.txt) cohabit
+            # under different keys; no overwrite needed.
+            if binary_md.event_datetime and not report_dict.get("event_type"):
+                report_dict["event_type"] = (
+                    "Full Histogram" if is_histogram else "Full Waveform"
+                )
+
+        # Binary-derived peaks fill in when the .txt didn't supply them.
+        # They're ~3% low vs the device-authoritative .txt values (residual
+        # codec drift), so .txt always wins when present.
+        if binary_peaks is not None:
+            if binary_peaks.transverse_ips and not report_dict.get("tran_ppv"):
+                report_dict["tran_ppv"] = binary_peaks.transverse_ips
+            if binary_peaks.vertical_ips and not report_dict.get("vert_ppv"):
+                report_dict["vert_ppv"] = binary_peaks.vertical_ips
+            if binary_peaks.longitudinal_ips and not report_dict.get("long_ppv"):
+                report_dict["long_ppv"] = binary_peaks.longitudinal_ips
+
+        # 4. Build the typed IdfEvent.  Filename is authoritative for
         # (serial, timestamp, kind); the report's event_datetime takes
         # precedence over the filename timestamp inside from_report().
         idf_event = IdfEvent.from_report(report_dict, source_path.name)
@@ -511,7 +568,7 @@ class WaveformStore:
         # serial that overrides a misnamed export).
         serial = serial_hint or idf_event.serial or "UNKNOWN"
 
-        # Filesystem write.
+        # 5. Filesystem write of binary bytes.
         filename = source_path.name
         bw_path = self._serial_dir(serial) / filename
         bw_path.write_bytes(idf_bytes)
@@ -523,13 +580,41 @@ class WaveformStore:
         # surrogate — every distinct binary maps to a distinct row.
         waveform_key = bytes.fromhex(sha256)[:16]
 
-        # Bridge to minimateplus.Event for the existing sidecar / DB
+        # 6. Bridge to minimateplus.Event for the existing sidecar / DB
         # insert paths.  See IdfEvent.to_minimateplus_event() for the
         # caveats of this bridge (mic units, missing fields → sidecar).
         ev = idf_event.to_minimateplus_event(waveform_key)
 
-        # Write the sidecar.  Source kind "idf-import" was added to the
-        # allow-list in event_file_io.event_to_sidecar_dict for this.
+        # Attach the decoded sample arrays.  Thor's decoder counts use
+        # LSB = 0.0003 in/s for geo (vs BW's 16-count units at 0.005 in/s)
+        # — the .h5 writer's geo_range="normal" yields LSB = 10/32768
+        # ≈ 0.000305 in/s, so plotted samples come out ~1.7% high.
+        # Acceptable known offset; refine with a Thor-aware h5 path later.
+        if idf_samples is not None:
+            ev.raw_samples = idf_samples
+            n_samples = max((len(idf_samples.get(ch, [])) for ch in ("Tran", "Vert", "Long", "MicL")), default=0)
+            ev.total_samples = ev.total_samples or n_samples
+
+        # 7. Write the .h5 clean-waveform file when we actually have samples.
+        # Histograms (IDFH) don't have waveform samples — skip h5 for those.
+        hdf5_filename: Optional[str] = None
+        if idf_samples is not None and not is_histogram:
+            hdf5_path = self.hdf5_path_for(serial, filename)
+            try:
+                event_hdf5.write_event_hdf5(
+                    hdf5_path, ev,
+                    serial=serial,
+                    geo_range="normal",   # Thor's geo full scale is also 10 in/s (Normal)
+                    source_kind="idf-import",
+                )
+                hdf5_filename = hdf5_path.name
+            except Exception as exc:
+                log.warning(
+                    "save_imported_idf: HDF5 write failed for %s: %s — continuing without .h5",
+                    hdf5_path, exc,
+                )
+
+        # 8. Write the sidecar.  Source kind "idf-import" is on the allow-list.
         sidecar_path = self.sidecar_path_for(serial, filename)
         existing_review = None
         if sidecar_path.exists():
@@ -554,19 +639,46 @@ class WaveformStore:
         # Time of Peak, sensor self-check, calibration, firmware).
         if report_dict:
             sidecar["extensions"]["idf_report"] = report_dict
+        # For histograms, also stash the binary-decoded per-interval
+        # records so the UI / report layer doesn't need to re-walk the
+        # IDFH file at render time.
+        if idf_intervals is not None:
+            sidecar["extensions"]["idf_intervals"] = [
+                {
+                    "offset":     iv.offset,
+                    "tran_peak":  iv.peak_count("Tran"),
+                    "tran_halfp": iv.tran_halfp,
+                    "tran_freq":  iv.freq_hz("Tran"),
+                    "vert_peak":  iv.peak_count("Vert"),
+                    "vert_halfp": iv.vert_halfp,
+                    "vert_freq":  iv.freq_hz("Vert"),
+                    "long_peak":  iv.peak_count("Long"),
+                    "long_halfp": iv.long_halfp,
+                    "long_freq":  iv.freq_hz("Long"),
+                    "mic_peak":   iv.peak_count("MicL"),
+                    "mic_halfp":  iv.micl_halfp,
+                    "mic_freq":   iv.freq_hz("MicL"),
+                }
+                for iv in idf_intervals
+            ]
         event_file_io.write_sidecar(sidecar_path, sidecar)
 
         log.info(
             "WaveformStore.save_imported_idf serial=%s filename=%s filesize=%d "
-            "report_attached=%s",
-            serial, filename, filesize, bool(report_dict),
+            "kind=%s report_attached=%s binary_decoded=%s h5=%s intervals=%d",
+            serial, filename, filesize,
+            "histogram" if is_histogram else "waveform",
+            bool(report_dict),
+            (idf_samples is not None) or (idf_intervals is not None),
+            hdf5_filename or "(skipped)",
+            len(idf_intervals) if idf_intervals else 0,
         )
         return ev, {
             "filename":           filename,
             "filesize":           filesize,
             "sha256":             sha256,
             "a5_pickle_filename": None,
-            "hdf5_filename":      None,
+            "hdf5_filename":      hdf5_filename,
             "sidecar_filename":   sidecar_path.name,
             "serial":             serial,
         }