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Python
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#!/usr/bin/env python3
"""Inspect a remote GGUF's metadata + tensor names without downloading the weights.
The interesting part of a GGUF (architecture, block_count, nextn_predict_layers,
tensor names) all lives in the header, which is a few MB even for a 100 GB file.
This range-fetches the first chunk and parses the header directly.
usage:
scripts/gguf-header-peek.py <hf-repo-id> [filename-substring]
scripts/gguf-header-peek.py /path/to/local.gguf
examples:
scripts/gguf-header-peek.py EasiiX/Qwen3.8-Flash-Next-MTP-Strix-Halo-GGUF
scripts/gguf-header-peek.py unsloth/Qwen3.8-Flash-Next-GGUF Q3_K_XL
"""
import struct
import subprocess
import sys
import tempfile
CHUNK = 96 * 1024 * 1024 # header is dominated by the tokenizer strings
SCALAR_BYTES = {0: 1, 1: 1, 2: 2, 3: 2, 4: 4, 5: 4, 6: 4, 7: 1, 10: 8, 11: 8, 12: 8}
SCALAR_FMT = {0: "<B", 1: "<b", 2: "<H", 3: "<h", 4: "<I", 5: "<i",
6: "<f", 7: "<B", 10: "<Q", 11: "<q", 12: "<d"}
TYPE_NAMES = {0: "u8", 1: "i8", 2: "u16", 3: "i16", 4: "u32", 5: "i32", 6: "f32",
7: "bool", 8: "str", 9: "arr", 10: "u64", 11: "i64", 12: "f64"}
class Reader:
def __init__(self, fh):
self.fh = fh
def u32(self):
return struct.unpack("<I", self.fh.read(4))[0]
def u64(self):
return struct.unpack("<Q", self.fh.read(8))[0]
def string(self):
return self.fh.read(self.u64()).decode("utf-8", "replace")
def value(self, vtype):
if vtype == 8:
return self.string()
if vtype == 9:
sub, count = self.u32(), self.u64()
if count > 32:
for _ in range(count):
self.value(sub)
return f"<{count} x {TYPE_NAMES.get(sub, sub)}>"
return [self.value(sub) for _ in range(count)]
if vtype in SCALAR_BYTES:
raw = self.fh.read(SCALAR_BYTES[vtype])
if len(raw) < SCALAR_BYTES[vtype]:
raise ValueError("truncated header: increase CHUNK")
if vtype == 7:
return bool(raw[0])
return struct.unpack(SCALAR_FMT[vtype], raw)[0]
raise ValueError(f"unknown gguf value type {vtype}")
def parse(path):
with open(path, "rb") as fh:
r = Reader(fh)
assert fh.read(4) == b"GGUF", "not a GGUF file"
version, n_tensors, n_kv = r.u32(), r.u64(), r.u64()
kv = {r.string(): r.value(r.u32()) for _ in range(n_kv)}
names = []
for _ in range(n_tensors):
names.append(r.string())
r.fh.read(8 * r.u32()) # dims
r.fh.read(12) # type + offset
return version, kv, names
def fetch(repo, want):
listing = subprocess.run(
["curl", "-s", f"https://huggingface.co/api/models/{repo}"],
capture_output=True, text=True, check=True).stdout
import json
files = [s["rfilename"] for s in json.loads(listing)["siblings"]
if s["rfilename"].endswith(".gguf")]
matches = [f for f in files if want in f] if want else files
if not matches:
raise SystemExit(f"no .gguf matching {want!r} in {repo}")
name = sorted(matches)[0]
print(f"repo: {repo}\nfile: {name} (of {len(files)} gguf files)")
url = f"https://huggingface.co/{repo}/resolve/main/{name}"
tmp = tempfile.NamedTemporaryFile(suffix=".gguf", delete=False)
subprocess.run(["curl", "-sL", "-r", f"0-{CHUNK}", "-o", tmp.name, url], check=True)
return tmp.name
def main():
if len(sys.argv) < 2:
raise SystemExit(__doc__)
target = sys.argv[1]
if target.startswith(("http", "/")) and target.endswith(".gguf"):
path = target if target.startswith("/") else fetch(target, "")
else:
path = fetch(target, sys.argv[2] if len(sys.argv) > 2 else "")
version, kv, names = parse(path)
arch = kv.get("general.architecture", "?")
print(f"gguf v{version} arch={arch} tensors={len(names)} kv={len(kv)}")
print("\n-- key metadata --")
for k in sorted(kv):
if k.startswith("tokenizer.") or k.startswith("general."):
continue
v = kv[k]
if isinstance(v, list) and len(v) > 12:
v = f"{v[:12]} ... (len {len(v)})"
print(f" {k:<46} {v}")
blocks = sorted({n.split(".")[1] for n in names
if n.startswith("blk.") and n.split(".")[1].isdigit()})
print(f"\n-- block indices: {blocks[:12]}{' ...' if len(blocks) > 12 else ''} "
f"({len(blocks)} total)")
suffixes = sorted({n.split(".", 2)[2] for n in names
if n.startswith("blk.") and len(n.split(".")) > 2})
print(f"-- per-block suffixes ({len(suffixes)}):")
for s in suffixes:
print(f" {s}")
other = sorted(n for n in names if not n.startswith("blk."))
if other:
print("-- non-block tensors:")
for n in other:
print(f" {n}")
if __name__ == "__main__":
main()