diff --git a/5-Applications/tools-scripts/famm/semantic_mass_z_accelerator.py b/5-Applications/tools-scripts/famm/semantic_mass_z_accelerator.py
new file mode 100644
index 00000000..05cb4c25
--- /dev/null
+++ b/5-Applications/tools-scripts/famm/semantic_mass_z_accelerator.py
@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+"""Semantic Mass Z-domain accelerator receipt.
+
+Fits a simple autoregressive recurrence to a semantic mass stream and emits a
+FAMM routing receipt. This is a lightweight measured shortcut: it turns
+history into coefficients + state + residual seal.
+
+The runner is intentionally small. It is not proof; it is a computational
+routing witness.
+"""
+
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+from pathlib import Path
+from typing import Any
+
+import numpy as np
+
+
+def sha256_json(value: Any) -> str:
+    payload = json.dumps(value, sort_keys=True, separators=(",", ":")).encode("utf-8")
+    return hashlib.sha256(payload).hexdigest()
+
+
+def fit_ar(sequence: np.ndarray, order: int) -> tuple[np.ndarray, np.ndarray, float]:
+    if order < 1:
+        raise ValueError("order must be >= 1")
+    if len(sequence) <= order + 1:
+        raise ValueError("sequence too short for requested AR order")
+
+    y = sequence[order:]
+    X = np.column_stack([sequence[order - i - 1 : len(sequence) - i - 1] for i in range(order)])
+    coeffs, *_ = np.linalg.lstsq(X, y, rcond=None)
+    pred = X @ coeffs
+    residual = y - pred
+    rmse = float(np.sqrt(np.mean(residual**2)))
+    return coeffs, residual, rmse
+
+
+def route_from_poles(poles: np.ndarray, rmse: float, cfg: dict[str, Any]) -> dict[str, Any]:
+    pole_abs = np.abs(poles)
+    max_abs = float(np.max(pole_abs)) if len(pole_abs) else 0.0
+    near_unit_tol = float(cfg.get("near_unit_tol", 0.05))
+    stable_radius = float(cfg.get("stable_radius", 1.0))
+    residual_max = float(cfg.get("residual_rmse_max", 0.1))
+
+    if max_abs >= stable_radius:
+        route = "closure_or_quarantine"
+        reason = "pole outside admissible stable ROC"
+    elif np.any(np.abs(pole_abs - 1.0) <= near_unit_tol):
+        route = "long_memory_delta_mem"
+        reason = "pole near unit circle indicates long semantic memory"
+    elif rmse <= residual_max:
+        route = "carry_recurrence_seal_residual"
+        reason = "stable recurrence with bounded residual"
+    else:
+        route = "increase_order_or_seal_residual"
+        reason = "stable but residual exceeds configured bound"
+
+    return {
+        "route": route,
+        "reason": reason,
+        "max_abs_pole": max_abs,
+        "pole_abs": [float(x) for x in pole_abs.tolist()],
+        "residual_rmse": rmse,
+    }
+
+
+def run(config: dict[str, Any]) -> dict[str, Any]:
+    seq = np.array(config["semantic_mass_sequence"], dtype=float)
+    order = int(config.get("ar_order", 4))
+    coeffs, residual, rmse = fit_ar(seq, order)
+
+    # AR recurrence: mu[k] = sum_i a_i mu[k-i]
+    # Characteristic: lambda^p - a1 lambda^(p-1) - ... - ap = 0
+    poly = np.concatenate([[1.0], -coeffs])
+    poles = np.roots(poly)
+
+    decision = route_from_poles(poles, rmse, config.get("route_thresholds", {}))
+
+    receipt = {
+        "receipt_type": "famm_semantic_mass_z_receipt",
+        "schema_version": "0.1.0",
+        "basis_layer": "MASS_Z_ACCEL",
+        "ar_order": order,
+        "sequence_len": int(len(seq)),
+        "coefficients": [float(x) for x in coeffs.tolist()],
+        "poles": [{"re": float(p.real), "im": float(p.imag), "abs": float(abs(p))} for p in poles],
+        "residual": {
+            "rmse": rmse,
+            "samples_sha256": sha256_json([float(x) for x in residual.tolist()]),
+            "max_abs": float(np.max(np.abs(residual))),
+        },
+        "route_decision": decision,
+        "no_drift_boundary": (
+            "This is a computational recurrence witness for Semantic Mass routing. "
+            "It is not proof and does not replace exact receipts."
+        ),
+    }
+    receipt["receipt_sha256"] = sha256_json(receipt)
+    return receipt
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--config", required=True)
+    parser.add_argument("--out", required=True)
+    args = parser.parse_args()
+
+    cfg = json.loads(Path(args.config).read_text(encoding="utf-8"))
+    receipt = run(cfg)
+
+    out_path = Path(args.out)
+    out_path.parent.mkdir(parents=True, exist_ok=True)
+    out_path.write_text(json.dumps(receipt, indent=2, sort_keys=True), encoding="utf-8")
+
+    print(f"Wrote {out_path}")
+    print(f"Route: {receipt['route_decision']['route']} — {receipt['route_decision']['reason']}")
+    print(f"Receipt SHA-256: {receipt['receipt_sha256']}")
+
+
+if __name__ == "__main__":
+    main()