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esh-pfi-infrastructure/services/grok-token-broker/broker.py
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#!/usr/bin/env python3
"""Grok token broker — hold a refreshable xAI session credential WITHOUT touching the CLI's.
⭐ THE PROBLEM. The Grok Build coding plan (`https://cli-chat-proxy.grok.com/v1`, serving
grok-4.6) authenticates with an OIDC **session** token, not an API key: `api_key: null`,
`env_key: null` in the CLI's own model cache. It expires roughly every six hours. LiteLLM and
every other gateway on this fleet hold a STATIC credential, so a naive alias works until the
session lapses and then fails closed.
⚠⚠ THE HAZARD THAT SHAPES THIS ENTIRE DESIGN, AND WHY IT IS NOT A SIMPLE REFRESH LOOP.
`https://auth.x.ai/oauth2/token` supports the `refresh_token` grant. But **a refresh may ROTATE
the refresh token**, and many OIDC providers invalidate the old one server-side the instant a
new one is issued. The operator's interactive `grok` CLI holds its refresh token in
`~/.grok/auth.json`. If xAI rotates-and-invalidates, then a broker refreshing against the SAME
credential silently kills the CLI login — and it does so **even though the broker never writes
to that file.** Not-writing is necessary and NOT sufficient; the damage would be server-side.
heid's `groa_http_dispatch.py` refuses to refresh at all for this reason, which is the correct
call absent an answer. This broker's job is to get the answer first and then act on it.
⛔ SO THE REFRESH LOOP IS NOT ARMED UNTIL `probe-rotation` HAS RUN AND SAID IT IS SAFE.
`serve` and `refresh` both refuse without a stored probe verdict. That is deliberate: this is a
tool whose whole value is contingent on one unknown, and running it before measuring the unknown
is how you find out by breaking the operator's login.
## The probe, and what each outcome means
`probe-rotation` performs ONE refresh using a COPY of the credential, then re-presents the
ORIGINAL refresh token:
original still valid -> NON-ROTATING (or rotation without invalidation). The broker can
coexist with the CLI on one credential. Loop may be armed.
original now rejected -> ROTATING-AND-INVALIDATING. The broker MUST NOT share the CLI's
credential. It needs its own login, or the idea is dead. Refuses
to arm, and says so.
⚠ The probe itself consumes one refresh. If the answer is "rotating", the CLI's token is
already dead by the time you read the verdict — there is no way to ask this question without
spending the credential, and pretending otherwise would be worse. The remedy is a `grok` CLI
re-login, which is the same remedy heid's exit-3 path already names. **Run it when a broken CLI
login is a two-minute annoyance, not mid-panel.**
## What it never does
- Never writes `~/.grok/auth.json`. Reads it once, on `seed`, and never again.
- Never prints a token to stdout except under `token --raw`, which is for a consumer to capture.
- Never logs a token value. Expiry, scope and subject only.
"""
from __future__ import annotations
import argparse
import base64
import json
import os
import pathlib
import sys
import time
import urllib.error
import urllib.parse
import urllib.request
CLI_AUTH = pathlib.Path.home() / ".grok" / "auth.json"
STORE = pathlib.Path(os.environ.get("GROK_BROKER_HOME",
pathlib.Path.home() / ".config" / "grok-token-broker"))
CRED = STORE / "credential.json"
VERDICT = STORE / "rotation-verdict.json"
TOKEN_URL = "https://auth.x.ai/oauth2/token"
API_BASE = "https://cli-chat-proxy.grok.com/v1"
REFRESH_MARGIN_S = 1800 # refresh when under 30 min remain
def _claims(jwt: str) -> dict:
pl = jwt.split(".")[1]
pl += "=" * (-len(pl) % 4)
return json.loads(base64.urlsafe_b64decode(pl))
def _remaining(jwt: str) -> int:
try:
return int(_claims(jwt)["exp"] - time.time())
except Exception:
return -1
def _post_form(url: str, fields: dict, timeout: int = 30):
data = urllib.parse.urlencode(fields).encode()
req = urllib.request.Request(url, data=data,
headers={"Content-Type": "application/x-www-form-urlencoded"})
try:
with urllib.request.urlopen(req, timeout=timeout) as r:
return r.status, json.loads(r.read())
except urllib.error.HTTPError as e:
body = e.read().decode("utf-8", "replace")[:400]
return e.code, {"_error": body}
except Exception as e: # noqa: BLE001
return 0, {"_error": f"{type(e).__name__}: {e}"}
def _read_cli_credential() -> dict:
"""Pull access token, refresh token and client id out of the CLI's auth file.
Shape-tolerant on purpose: this file belongs to another tool and its layout is not ours to
depend on. Anything not found is reported, never guessed.
"""
if not CLI_AUTH.exists():
raise SystemExit(f"REFUSING: no CLI credential at {CLI_AUTH}")
blob = json.loads(CLI_AUTH.read_text(encoding="utf-8"))
found: dict = {}
def walk(o, key_hint=""):
if isinstance(o, dict):
for k, v in o.items():
if isinstance(v, str):
if k == "key" and v.count(".") == 2 and "access" not in found:
found["access"] = v
elif "refresh" in k.lower() and len(v) > 20:
found.setdefault("refresh", v)
walk(v, k)
if "auth.x.ai::" in key_hint:
found.setdefault("client_id", key_hint.split("::", 1)[1])
elif isinstance(o, list):
for v in o:
walk(v, key_hint)
for k, v in blob.items():
walk(v, k)
missing = [f for f in ("access", "refresh") if f not in found]
if missing:
raise SystemExit(f"REFUSING: could not locate {missing} in {CLI_AUTH}. "
"Its layout changed; inspect it by hand rather than letting this guess.")
return found
def cmd_seed(_a) -> int:
STORE.mkdir(parents=True, exist_ok=True)
os.chmod(STORE, 0o700)
c = _read_cli_credential()
CRED.write_text(json.dumps({**c, "seeded_at": time.strftime("%Y-%m-%dT%H:%M:%S%z"),
"source": str(CLI_AUTH)}, indent=2), encoding="utf-8")
os.chmod(CRED, 0o600)
cl = _claims(c["access"])
print(f" seeded -> {CRED} (0600)")
print(f" scope : {cl.get('scope')}")
print(f" expires : {time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime(cl['exp']))} "
f"({_remaining(c['access']) // 60} min left)")
print(f" client : {c.get('client_id', '<not found>')}")
print("\n ⛔ The refresh loop is NOT armed. Run `probe-rotation` next, and read its warning "
"first — the probe spends one refresh and may end the CLI's session.")
return 0
def cmd_probe(a) -> int:
if not CRED.exists():
raise SystemExit("REFUSING: run `seed` first")
c = json.loads(CRED.read_text(encoding="utf-8"))
if not a.i_accept_this_may_end_the_cli_session:
print("REFUSING without --i-accept-this-may-end-the-cli-session.\n\n"
" This probe performs a real refresh. If xAI rotates AND invalidates, the\n"
" operator's `grok` CLI login dies at that moment and needs an interactive\n"
" re-login. There is no way to answer the question without spending the\n"
" credential. Run it when that is a two-minute annoyance, not mid-panel.",
file=sys.stderr)
return 2
old_refresh = c["refresh"]
fields = {"grant_type": "refresh_token", "refresh_token": old_refresh}
if c.get("client_id"):
fields["client_id"] = c["client_id"]
print(" [1/2] refreshing with the stored refresh token ...")
st, body = _post_form(TOKEN_URL, fields)
if st != 200:
print(f" refresh FAILED http={st}: {str(body.get('_error'))[:200]}", file=sys.stderr)
print(" Verdict NOT recorded. The loop stays disarmed.", file=sys.stderr)
return 4
new_refresh = body.get("refresh_token")
rotated = bool(new_refresh and new_refresh != old_refresh)
print(f" ok. refresh_token {'ROTATED' if rotated else 'unchanged'}")
if not rotated:
verdict, safe = "non-rotating", True
note = "Provider returned the same refresh token; the CLI's copy is untouched."
else:
print(" [2/2] re-presenting the ORIGINAL refresh token to see if it still works ...")
st2, _ = _post_form(TOKEN_URL, fields)
if st2 == 200:
verdict, safe = "rotating-old-still-valid", True
note = ("Rotation happens but the old refresh token still works, so the CLI's copy "
"survives. Coexistence is safe.")
else:
verdict, safe = "rotating-and-invalidating", False
note = (f"The original refresh token is now rejected (http={st2}). The CLI's login "
"is ALREADY DEAD and needs an interactive `grok` re-login. A broker MUST "
"NOT share this credential — it needs its own login.")
print(f" original token -> http={st2}")
c["access"] = body.get("access_token", c["access"])
if new_refresh:
c["refresh"] = new_refresh
CRED.write_text(json.dumps(c, indent=2), encoding="utf-8")
os.chmod(CRED, 0o600)
VERDICT.write_text(json.dumps({
"verdict": verdict, "safe_to_arm": safe, "note": note,
"probed_at": time.strftime("%Y-%m-%dT%H:%M:%S%z"),
"token_url": TOKEN_URL, "api_base": API_BASE,
}, indent=2), encoding="utf-8")
os.chmod(VERDICT, 0o600)
print(f"\n VERDICT: {verdict} (safe_to_arm={safe})\n {note}")
if not safe:
print("\n ⚠ TELL THE OPERATOR: the `grok` CLI on this box needs a re-login.", file=sys.stderr)
return 0 if safe else 5
def _ensure_armed() -> dict:
if not VERDICT.exists():
raise SystemExit("REFUSING: no rotation verdict. Run `probe-rotation` first — this tool "
"will not refresh a credential whose rotation behaviour is unmeasured.")
v = json.loads(VERDICT.read_text(encoding="utf-8"))
if not v.get("safe_to_arm"):
raise SystemExit(f"REFUSING: verdict is '{v['verdict']}'. {v['note']}")
return v
def cmd_refresh(_a) -> int:
_ensure_armed()
c = json.loads(CRED.read_text(encoding="utf-8"))
fields = {"grant_type": "refresh_token", "refresh_token": c["refresh"]}
if c.get("client_id"):
fields["client_id"] = c["client_id"]
st, body = _post_form(TOKEN_URL, fields)
if st != 200:
print(f"refresh failed http={st}: {str(body.get('_error'))[:200]}", file=sys.stderr)
return 4
c["access"] = body["access_token"]
if body.get("refresh_token"):
c["refresh"] = body["refresh_token"]
c["refreshed_at"] = time.strftime("%Y-%m-%dT%H:%M:%S%z")
CRED.write_text(json.dumps(c, indent=2), encoding="utf-8")
os.chmod(CRED, 0o600)
print(f" refreshed; {_remaining(c['access']) // 60} min remaining")
return 0
def cmd_token(a) -> int:
"""Print a currently-valid access token, refreshing first if it is close to expiry."""
if not CRED.exists():
raise SystemExit("REFUSING: run `seed` first")
c = json.loads(CRED.read_text(encoding="utf-8"))
if _remaining(c["access"]) < REFRESH_MARGIN_S:
_ensure_armed()
if cmd_refresh(a) != 0:
return 4
c = json.loads(CRED.read_text(encoding="utf-8"))
if a.raw:
sys.stdout.write(c["access"])
else:
print(f" valid for {_remaining(c['access']) // 60} more minutes "
f"(use --raw to emit the token itself)")
return 0
def cmd_status(_a) -> int:
print(f" store : {STORE}")
if not CRED.exists():
print(" state : NOT SEEDED")
return 0
c = json.loads(CRED.read_text(encoding="utf-8"))
print(f" seeded : {c.get('seeded_at')} from {c.get('source')}")
print(f" access : {_remaining(c['access']) // 60} min remaining")
if VERDICT.exists():
v = json.loads(VERDICT.read_text(encoding="utf-8"))
print(f" rotation: {v['verdict']} safe_to_arm={v['safe_to_arm']} ({v['probed_at']})")
print(f" armed : {'YES' if v['safe_to_arm'] else 'NO — ' + v['verdict']}")
else:
print(" rotation: UNMEASURED — loop disarmed, `token` will refuse to refresh")
print(f" api_base: {API_BASE}")
return 0
def main() -> int:
ap = argparse.ArgumentParser(description=__doc__.split("\n")[0])
sub = ap.add_subparsers(dest="cmd", required=True)
sub.add_parser("seed", help="copy the CLI credential into the broker's own store")
p = sub.add_parser("probe-rotation", help="measure whether refresh rotates AND invalidates")
p.add_argument("--i-accept-this-may-end-the-cli-session", action="store_true")
sub.add_parser("refresh", help="refresh now (requires a safe verdict)")
t = sub.add_parser("token", help="emit a valid access token, refreshing if near expiry")
t.add_argument("--raw", action="store_true")
sub.add_parser("status", help="report state without touching anything")
a = ap.parse_args()
return {"seed": cmd_seed, "probe-rotation": cmd_probe, "refresh": cmd_refresh,
"token": cmd_token, "status": cmd_status}[a.cmd](a)
if __name__ == "__main__":
raise SystemExit(main())