diff --git a/opendbc_repo/opendbc/car/gm/longitudinal.py b/opendbc_repo/opendbc/car/gm/longitudinal.py
new file mode 100644
index 0000000000..971ed1d1e4
--- /dev/null
+++ b/opendbc_repo/opendbc/car/gm/longitudinal.py
@@ -0,0 +1,404 @@
+"""GM longitudinal tuning on the acceleration interface."""
+
+from dataclasses import dataclass, field
+import math
+
+import numpy as np
+
+from opendbc.car.gm.values import (gm_control_word, CAR, GMFlags, GMSafetyFlags, PEDAL_BOLT_CAR, NO_ACC_BOLT_CAR, is_volt_longitudinal,
+                                  is_volt_gateway_longitudinal, is_bolt_euv_longitudinal, is_ordinary_ascm_profile, is_ordinary_sdgm_profile)
+from opendbc.car.structs import car
+
+
+REGEN_SPEED = (0.0, 1.5, 4.0, 8.0, 15.0, 30.0)
+REGEN_LIMIT = (-0.93, -1.28, -1.98, -2.58, -2.86, -2.95)
+PEDAL_KP_BP = (0.0, 5.0, 15.0, 35.0)
+PEDAL_KP_V = (0.095, 0.085, 0.065, 0.050)
+PEDAL_FEEDFORWARD_GAIN = 0.20
+
+
+@dataclass(frozen=True)
+class PedalStartEvidence:
+  drive_id: int
+  observed_ns: int
+  has_lead: bool
+  traffic_mode: bool = False
+  custom_acceleration: bool = False
+  profile_max_accel: float | None = None
+
+
+class GMPedalStartPolicy:
+  def __init__(self):
+    self.reset()
+
+  def reset(self):
+    self.handoff_frames = 0
+    self.drive_id = None
+    self.last_ns = None
+    self.release_since_ns = None
+
+  def transition(self, native, previous, active, cs, target, should_stop, evidence):
+    states = car.CarControl.Actuators.LongControlState
+    valid = (isinstance(evidence, PedalStartEvidence) and active and cs.canValid and not cs.canTimeout and
+             not cs.brakePressed and not cs.gasPressed and math.isfinite(target) and math.isfinite(cs.vEgo) and
+             evidence.drive_id > 0 and evidence.observed_ns > evidence.drive_id and
+             (evidence.profile_max_accel is None or math.isfinite(evidence.profile_max_accel)))
+    if not valid:
+      self.reset()
+      return states.pid if native == states.starting else native
+    if (self.drive_id != evidence.drive_id or self.last_ns is None or
+        not 0 < evidence.observed_ns - self.last_ns <= 20_000_000):
+      self.release_since_ns = None
+      self.handoff_frames = 0
+    self.drive_id, self.last_ns = evidence.drive_id, evidence.observed_ns
+    if should_stop:
+      self.release_since_ns = None
+      return states.stopping
+    if previous == states.stopping:
+      immediate = cs.vEgo > 0.35 or (evidence.has_lead and target > 0.15) or (target >= 0.45 and not cs.cruiseState.standstill)
+      if target > 0.15:
+        if self.release_since_ns is None:
+          self.release_since_ns = evidence.observed_ns
+      else:
+        self.release_since_ns = None
+      settled = self.release_since_ns is not None and evidence.observed_ns - self.release_since_ns >= 340_000_000
+      return states.starting if immediate or settled else states.stopping
+    self.release_since_ns = None
+    if previous == states.off:
+      return states.starting
+    return states.pid if cs.vEgo > 0.35 else previous
+
+  @staticmethod
+  def output(target, evidence):
+    if evidence.traffic_mode or evidence.custom_acceleration or (evidence.has_lead and target <= 0.25):
+      return float(np.clip(target, 0.0, 0.55))
+    if evidence.profile_max_accel is not None and evidence.profile_max_accel > 0.0:
+      return min(0.55, evidence.profile_max_accel)
+    return 0.55
+
+  def handoff_output(self, output, last_output, target, speed, starting_handoff, should_stop, evidence):
+    if evidence is None or self.last_ns != evidence.observed_ns:
+      self.handoff_frames = 0
+      return output
+    if starting_handoff:
+      self.handoff_frames = 75
+    if not (self.handoff_frames > 0 and evidence.has_lead and not should_stop and target > 0.15 and speed < 1.25):
+      self.handoff_frames = 0
+      return output
+    self.handoff_frames -= 1
+    speed_floor = float(np.interp(speed, (0.0, 0.5, 1.25), (0.22, 0.18, 0.10)))
+    target_floor = min(speed_floor, max(0.0, 0.4 * target))
+    return max(output, min(last_output, target_floor))
+
+
+def _interp(value, points, values):
+  return float(np.interp(value, points, values))
+
+
+@dataclass
+class GMPedalLongitudinalPolicy:
+  friction_variant: bool
+  ignore_cruise_standstill: bool = False
+  stopping_decel_rate: float = field(default=0.8, init=False)
+  kp: tuple[tuple[float, ...], tuple[float, ...]] = (PEDAL_KP_BP, PEDAL_KP_V)
+  last_a_target: float = field(default=0.0, init=False)
+  integrator_hold_frames: int = field(default=0, init=False)
+
+  def stopping_output(self, output: float, target: float, should_stop: bool, cs) -> float:
+    return _moving_stop_target_follow(output, target, should_stop, cs)
+
+  def reset(self) -> None:
+    self.last_a_target = 0.0
+    self.integrator_hold_frames = 0
+
+  def prepare_pid(self, pid, target: float, error: float, speed: float,
+                  last_output: float, accel_limits: tuple[float, float], *,
+                  should_stop: bool = False, has_lead: bool | None = None) -> bool:
+    if pid.i > 0.0 and target < -0.05 and error < -0.25 and not (speed <= 0.35 and target > -0.40):
+      bleed = _interp(abs(error), (0.25, 0.75, 1.5), (0.55, 0.25, 0.0))
+      pid.i *= bleed
+
+    handoff_threshold = _interp(speed, (0.0, 4.0, 12.0, 25.0), (0.35, 0.45, 0.55, 0.70))
+    hold_frames = int(round(_interp(speed, (0.0, 4.0, 12.0, 25.0), (25.0, 20.0, 14.0, 10.0))))
+    if abs(target - self.last_a_target) > handoff_threshold:
+      self.integrator_hold_frames = max(self.integrator_hold_frames, hold_frames)
+    self.last_a_target = target
+    if self.integrator_hold_frames > 0:
+      self.integrator_hold_frames -= 1
+
+    at_neg_sat = last_output <= accel_limits[0] + 0.03
+    at_pos_sat = last_output >= accel_limits[1] - 0.03
+    sat_pushing_lower = at_neg_sat and error < -0.05
+    sat_pushing_upper = at_pos_sat and error > 0.05
+    return self.integrator_hold_frames > 0 or sat_pushing_lower or sat_pushing_upper
+
+  def feedforward(self, target: float, speed: float, last_output: float) -> float:
+    gain = PEDAL_FEEDFORWARD_GAIN
+    if self.friction_variant and target < 0.0:
+      regen_limit = _interp(speed, REGEN_SPEED, REGEN_LIMIT)
+      restore = 0.0
+      if target < regen_limit:
+        restore = _interp(regen_limit - target, (0.0, 0.25, 0.75), (0.0, 0.6, 1.0))
+      if speed > 5.0 and target < -1.10:
+        gap = max(0.0, abs(target) - abs(min(last_output, 0.0)))
+        target_restore = _interp(abs(target), (1.1, 1.6, 2.2, 3.0), (0.0, 0.25, 0.55, 1.0))
+        gap_restore = _interp(gap, (0.2, 0.6, 1.0, 1.6), (0.0, 0.25, 0.60, 1.0))
+        speed_factor = _interp(speed, (5.0, 8.0, 12.0, 18.0), (0.0, 0.35, 0.75, 1.0))
+        restore = max(restore, max(target_restore, gap_restore) * speed_factor)
+      gain += (1.0 - gain) * float(np.clip(restore, 0.0, 1.0))
+    return target * gain
+
+  def shape_output(self, output: float, target: float, error: float, speed: float) -> float:
+    if output > 0.0 and target < -0.10 and error < -0.35 and not (speed <= 0.35 and target > -0.40):
+      positive_cap = _interp(target, (-1.5, -0.6, -0.1), (0.0, 0.0, 0.05))
+      output = min(output, positive_cap)
+    if output >= -0.05 or target >= -0.80 or speed <= 5.0:
+      return output
+    gap = max(0.0, abs(target) - abs(output))
+    if self.friction_variant:
+      bias = 0.0
+      if gap > 0.25:
+        speed_factor = _interp(speed, (5.0, 10.0, 15.0, 25.0), (0.0, 0.55, 0.85, 1.0))
+        max_bias = _interp(abs(target), (0.8, 1.4, 2.2, 3.5), (0.0, 0.14, 0.42, 0.70))
+        bias = min(gap * 0.30, max_bias) * speed_factor
+      regen_limit = _interp(speed, REGEN_SPEED, REGEN_LIMIT)
+      if target < regen_limit - 0.05:
+        friction_request = max(0.0, regen_limit - target)
+        if friction_request > 0.10:
+          speed_factor = _interp(speed, (5.0, 8.0, 12.0, 18.0, 25.0), (0.0, 0.45, 0.75, 0.90, 1.0))
+          demand_factor = _interp(friction_request, (0.10, 0.25, 0.50, 0.90, 1.30), (0.0, 0.22, 0.50, 0.78, 1.0))
+          floor = regen_limit - friction_request * float(np.clip(speed_factor * demand_factor, 0.0, 1.0))
+          bias = max(bias, output - floor)
+      return output - max(bias, 0.0)
+    if gap <= 0.40:
+      return output
+    speed_factor = _interp(speed, (5.0, 12.0, 25.0), (0.0, 0.7, 1.0))
+    max_bias = _interp(abs(target), (0.8, 2.0, 3.5), (0.0, 0.10, 0.20))
+    return output - min(gap * 0.12, max_bias) * speed_factor
+
+
+class GMVoltLongitudinalPolicy:
+  """Original Volt default law; optional test-ground tunes are excluded."""
+  friction_variant = False
+  stopping_decel_rate = 1.0
+  starting_speed = 0.25
+  kp = 0.0
+
+  def __init__(self, gateway: bool = False):
+    if gateway:
+      self.stopping_decel_rate = 3.0
+      self.starting_speed = 0.75
+
+  def stop_policy(self):
+    return GMVoltStopPolicy(self.starting_speed)
+
+  def stopping_output(self, output: float, target: float, should_stop: bool, cs) -> float:
+    return _moving_stop_target_follow(output, target, should_stop, cs, max(1.5, self.starting_speed + 1.0))
+
+  def reset(self) -> None:
+    pass
+
+  def prepare_pid(self, pid, target: float, error: float, speed: float,
+                  last_output: float, accel_limits: tuple[float, float], *,
+                  should_stop: bool = False, has_lead: bool | None = None) -> bool:
+    # Unknown transport must not look like an open road. Only qualified absence
+    # permits releasing negative I during settled cruise.
+    if (has_lead is False and not should_stop and speed >= 8.0 and
+        abs(target) <= 0.12 and abs(error) <= 0.12 and pid.i < 0.0):
+      pid.i *= 0.995
+    if pid.i > 0.0 and target < -0.05 and error < -0.25 and not (speed <= 0.35 and target > -0.40):
+      pid.i *= _interp(abs(error), (0.25, 0.75, 1.5), (0.55, 0.25, 0.0))
+    return False
+
+  def feedforward(self, target: float, speed: float, last_output: float) -> float:
+    return target
+
+  def shape_output(self, output: float, target: float, error: float, speed: float) -> float:
+    if output > 0.0 and target < -0.10 and error < -0.35 and not (speed <= 0.35 and target > -0.40):
+      return min(output, _interp(target, (-1.5, -0.6, -0.1), (0.0, 0.0, 0.05)))
+    return output
+
+
+def _moving_stop_target_follow(output: float, target: float, should_stop: bool, cs, min_speed: float = 1.5) -> float:
+  if should_stop and not cs.brakePressed and cs.vEgo > min_speed and target < output - 0.25:
+    step = _interp(cs.vEgo, (min_speed, 3.0, 6.0, 10.0), (0.02, 0.03, 0.05, 0.07))
+    return max(target, output - step)
+  return output
+
+
+@dataclass(frozen=True)
+class EuvLongitudinalEvidence:
+  drive_id: int
+  observed_ns: int
+  has_lead: bool
+
+
+@dataclass(frozen=True)
+class VoltStopEvidence:
+  drive_id: int
+  observed_ns: int
+  has_lead: bool
+
+
+class _GMDefaultStopPolicy:
+  """Default stop release with exact owner evidence and starting-speed contracts."""
+  def __init__(self, starting_speed: float, evidence_type):
+    self.starting_speed = starting_speed
+    self.evidence_type = evidence_type
+    self.reset()
+
+  def reset(self):
+    self.drive_id = None
+    self.last_ns = None
+    self.release_since_ns = None
+
+  def transition(self, native, previous, active, cs, target, should_stop, evidence):
+    states = car.CarControl.Actuators.LongControlState
+    if not active:
+      self.reset()
+      return states.off
+    valid = (isinstance(evidence, self.evidence_type) and cs.canValid and not cs.canTimeout and
+             not cs.brakePressed and not cs.gasPressed and math.isfinite(target) and math.isfinite(cs.vEgo) and
+             evidence.drive_id > 0 and evidence.observed_ns > evidence.drive_id and
+             isinstance(evidence.has_lead, bool))
+    if not valid:
+      self.reset()
+      # Missing transport is not evidence of an empty road or permission to leave a stop.
+      return states.stopping if previous == states.stopping else native
+    if (self.drive_id != evidence.drive_id or self.last_ns is None or
+        not 0 < evidence.observed_ns - self.last_ns <= 20_000_000):
+      self.release_since_ns = None
+    self.drive_id, self.last_ns = evidence.drive_id, evidence.observed_ns
+    if should_stop:
+      self.release_since_ns = None
+      return states.stopping
+    if previous != states.stopping:
+      self.release_since_ns = None
+      return native
+    immediate = (cs.vEgo > self.starting_speed or (evidence.has_lead and target > 0.15) or
+                 (target >= 0.45 and not cs.cruiseState.standstill))
+    if target > 0.15:
+      if self.release_since_ns is None:
+        self.release_since_ns = evidence.observed_ns
+    else:
+      self.release_since_ns = None
+    settled = self.release_since_ns is not None and evidence.observed_ns - self.release_since_ns >= 340_000_000
+    return states.pid if immediate or settled else states.stopping
+
+
+class GMEuvStopPolicy(_GMDefaultStopPolicy):
+  def __init__(self):
+    super().__init__(0.25, EuvLongitudinalEvidence)
+
+
+class GMVoltStopPolicy(_GMDefaultStopPolicy):
+  def __init__(self, starting_speed: float):
+    super().__init__(starting_speed, VoltStopEvidence)
+
+
+class GMOrdinaryLongitudinalPolicy:
+  """Common ordinary acceleration law; no pedal launch or optional profile shaping."""
+  friction_variant = False
+  stopping_decel_rate = 1.0
+  kp = 0.0
+
+  def reset(self) -> None:
+    pass
+
+  def prepare_pid(self, pid, target: float, error: float, speed: float,
+                  last_output: float, accel_limits: tuple[float, float], *,
+                  should_stop: bool = False, has_lead: bool | None = None) -> bool:
+    if pid.i > 0.0 and target < -0.05 and error < -0.25 and not (speed <= 0.35 and target > -0.40):
+      pid.i *= _interp(abs(error), (0.25, 0.75, 1.5), (0.55, 0.25, 0.0))
+    return False
+
+  def feedforward(self, target: float, speed: float, last_output: float) -> float:
+    return target
+
+  def shape_output(self, output: float, target: float, error: float, speed: float) -> float:
+    if output > 0.0 and target < -0.10 and error < -0.35 and not (speed <= 0.35 and target > -0.40):
+      return min(output, _interp(target, (-1.5, -0.6, -0.1), (0.0, 0.0, 0.05)))
+    return output
+
+  def stopping_output(self, output: float, target: float, should_stop: bool, cs) -> float:
+    return _moving_stop_target_follow(output, target, should_stop, cs)
+
+
+class GMEuvLongitudinalPolicy(GMOrdinaryLongitudinalPolicy):
+  stop_policy = GMEuvStopPolicy
+
+
+def euv_policy_for(cp) -> GMEuvLongitudinalPolicy | None:
+  return GMEuvLongitudinalPolicy() if is_bolt_euv_longitudinal(cp) else None
+
+
+def volt_policy_for(cp) -> GMVoltLongitudinalPolicy | None:
+  """Admit only the exact restored Volt longitudinal topologies."""
+  return GMVoltLongitudinalPolicy(is_volt_gateway_longitudinal(cp)) if is_volt_longitudinal(cp) else None
+
+
+def policy_for(cp) -> GMPedalLongitudinalPolicy | None:
+  """Admit only the already selected, exact GM Bolt interceptor path."""
+  try:
+    flags = gm_control_word(cp)
+    required = int(GMSafetyFlags.PEDAL_LONG | GMSafetyFlags.PADDLE_SCHED)
+    candidate = cp.carFingerprint
+    return (GMPedalLongitudinalPolicy(candidate == CAR.CHEVROLET_BOLT_ACC_2022_2023_PEDAL,
+                                        ignore_cruise_standstill=candidate in NO_ACC_BOLT_CAR)
+            if cp.brand == 'gm' and candidate in PEDAL_BOLT_CAR and
+            cp.openpilotLongitudinalControl and not cp.pcmCruise and
+            not cp.passive and not cp.dashcamOnly and not cp.notCar and
+            int(cp.flags) & int(GMFlags.PEDAL_LONG) and flags & required == required and
+            cp.safetyConfigs[0].safetyModel == car.CarParams.SafetyModel.gm and
+            (bool(flags & int(GMSafetyFlags.BOLT_ACC_PEDAL)) ==
+             (candidate == CAR.CHEVROLET_BOLT_ACC_2022_2023_PEDAL))
+            else None)
+  except (AttributeError, IndexError, TypeError, ValueError):
+    return None
+
+
+@dataclass(frozen=True)
+class AscmStopEvidence:
+  drive_id: int
+  observed_ns: int
+  has_lead: bool
+
+
+class GMAscmStopPolicy(_GMDefaultStopPolicy):
+  def __init__(self):
+    super().__init__(0.25, AscmStopEvidence)
+
+
+class GMAscmLongitudinalPolicy(GMOrdinaryLongitudinalPolicy):
+  """Ordinary ASCM acceleration law; no EV-specific settled-cruise recovery."""
+  stop_policy = GMAscmStopPolicy
+
+
+def ascm_policy_for(cp):
+  return GMAscmLongitudinalPolicy() if is_ordinary_ascm_profile(cp, longitudinal=True) else None
+
+
+class GMSdgmLongitudinalPolicy(GMOrdinaryLongitudinalPolicy):
+  """Ordinary SDGM acceleration law with the reached vehicle tune."""
+  def __init__(self, blazer):
+    self.stop_policy = lambda: _GMDefaultStopPolicy(0.35 if blazer else 0.25, AscmStopEvidence)
+    self.kp = ((0.0, 4.0, 12.0, 35.0), (0.09, 0.075, 0.055, 0.040)) if blazer else 0.0
+
+def sdgm_policy_for(cp):
+  return GMSdgmLongitudinalPolicy(cp.carFingerprint == CAR.CHEVROLET_BLAZER) if is_ordinary_sdgm_profile(cp, longitudinal=True) else None
+
+
+def volt_sng_release(cp, requested, cc, cs, now_ns, *, plan_current=False):
+  sources = getattr(cs, "volt_sng_sources", ())
+  current = bool(sources) and all(source > 0 and 0 <= now_ns - source <= limit for source, limit in sources)
+  return bool(requested and plan_current and is_volt_longitudinal(cp) and cc.enabled and cc.longActive and
+              cc.cruiseControl.resume and cs.out.cruiseState.standstill and
+              cs.out.canValid and not cs.out.canTimeout and not cs.out.gasPressed and not cs.out.brakePressed and
+              not cs.out.regenBraking and cs.out.gearShifter in (car.CarState.GearShifter.drive, car.CarState.GearShifter.low) and
+              current)
+
+
+def volt_sng_resume_policy_for(cp):
+  if not is_volt_longitudinal(cp):
+    return None
+  return lambda default, requested, fresh: default if not requested else bool(default and fresh)