Gevva0· Cascading Decision Engine
T-1T0T1T2
Introducing Gevva0

Stop generating tokens.

Start locking verdicts.

A local 4-Tier Cascading Decision Engine. Each request stops at the cheapest tier that can answer it with confidence. Only the hard cases reach the full LLM.

TIER −1 · RULES
< 50 µs
Static routing rules
TIER 0 · MARKOV
< 3 ms
Absorbing chains · 768D
TIER 1 · FAST-PATH
37 ms
K=64 logit scoring
TIER 2 · CoT
256 tok
Hot-KV reasoning
The Decision Trilemma

Accurate, fast, or cheap. Until now, pick two.

Frontier reasoning LLMClaude Opus 4.6 Thinking · JevBench
0 ms
Small 4B deciderImajev-4B · JevBench #1 entrant
0 ms
Gevva0 · 4-Tier CascadeGemma 4 26B-A4B · single local GPU
0 ms
Median (p50) latency, log scale. Source: JevBench report, Oct 2026.

Frontier LLMs

Accurate on complex policy, but 1,500–25,000 ms per call and $5–$40 per 1,000 decisions.

Small classifiers

Answer in 100–350 ms, but break down on multi-hop policy, temporal math, and prompt injection.

Gevva0

Intelligence 84.62 vs Opus 83.90, at a 44 ms median, on hardware you own, with no API bill.

The Cascade

Exit at the earliest tier that's sure.

TIER −1 · ROUTED
0
rule matches · 0 direct exits
TIER 0 · EXIT_0
0
5.0% · 100% accurate · 16.5 ms
TIER 1 · FAST-PATH
0
77.9% · 91.4% acc · 37 ms
TIER 2 · CoT
0
17.1% · 75.6% acc · 256 tok
Tier −1 · Static Rules

Routing in microseconds. No GPU involved.

Pre-compiled regex and keyword rules from RoutingRules/*.json run in under 50 µs and hot-reload without restarting the model.

FORCE_COT: temporal and financial math, probability, stoichiometry go straight to Tier 2
SKIP_TIER0: boolean logic, API schemas, and long legal text skip the embedding model, which handles them poorly
0 DIRECT_EXIT rules during benchmarks, so every scored answer comes from a model
● Tier −1 Rule Evaluator0.000 ms
P1 · Temporal, Rate-Limiting & Financial ArithmeticFORCE_COT
P2 · Probabilistic & Statistical ReasoningFORCE_COT
P3 · Nested Boolean & Symbolic LogicSKIP_TIER0
P6 · Hierarchical Legal & Policy (≥100 words)SKIP_TIER0
regex: \b(Give probabilities|conditional probability|Bayes|false-positive rate|base rate|…)\b
DIRECT_EXIT
FORCE_COT
SKIP_TIER0
EVALUATE_ALL
Tier 0 · Absorbing Markov Chains

Geometry instead of generation.

The query is embedded with EmbeddingGemma 2 (740M params, 768D). It then takes a random walk across domain landmarks until it lands in one of the candidate answers, and the landing probabilities are computed in closed form.

B = (I − Q)−1 R
Q: landmark→landmark transitions · R: landmark→answer absorption · final = 0.65·cosine + 0.35·Markov
JevBench: 12 / 12 early exits correct, 16.5 ms p50
Decision Index 0.3: all 344 / 344 out-of-domain items correctly passed up to Tier 1, zero false exits
● 768D Domain Manifoldembedding…
① Structural option & negation guard0.0 ms
② Landmark proximity dmin ≤ 0.22—
③ Entropy H ≤ 0.45 · margin Δ ≥ 0.25—
Tier 1 · Fast-Path

One forward pass. Zero tokens generated.

Gemma 4 26B-A4B (MoE, 4B active) reads the answer-letter logits directly from a single forward pass. The scores are auto-calibrated with Platt temperature scaling, so the confidence values can be trusted.

Only 52 tokens matter: ' A'…' Z' and 'A'…'Z'. So we patched the output head to project onto a 64-row slice instead of the full 262,144-token vocabulary.

Pac-Man p50, full vocab
37.0 ms
with K=64 micro-head
33.0
● Output projection z = h·Wᵀ262,144 rows
each cell = 64 vocabulary rows · 4,096 cells
−99.98% output-head GEMV · ≈5 ms saved per decision
[A] East · power pellet
0%
[B] North · hallway
0%
[C] Reverse
0%
Tier 2 · Bounded Chain-of-Thought

Reason only when it pays off.

When Tier 1 confidence is low, or a rule says FORCE_COT, the full LLM continues from the KV cache Tier 1 already filled. The prompt is never processed twice. It writes up to 256 tokens of reasoning (max_cot_tokens=256), then reads a calibrated answer.

The full vocabulary is restored only for the reasoning step (full_vocab_scope())
Up to 30% faster on long-context CoT
Probability accuracy 70% → 80%; 41 hard JevBench items handled
Asymmetric audit: quotes are extracted after the verdict is locked, so they can't change it
● Hot-KV continuationreuse_kv=True
Gevva0: Tier 1 prefill ■ → CoT continues in place ■
Naive: re-run the whole prompt before reasoning ■
hard-opus-a-temporal_numeric-12 · shift rest-period violations
Tier 1 fast-pathC ✗
Tier 2 verifiedB ✓
Three Demos · Try Them Locally

From arcade reflexes to game-theory-optimal play.

TIER 1TIER 2GAME-LOOP BRIDGE

Pac-Man

The rulebook stays pinned in KV cache. The next turn is decided while Pac-Man is still in the hallway, so it's ready by the junction with 0 ms wait.

p50 latency37.0 33 ms
Benchmarks · JevBench v1.6.1 & Decision Index 0.3

Frontier-level intelligence at a 44 ms median.

● JevBench composite (N=240, raw)intelligence · calibration · speed · cost
GPU-adjusted: 81.40 fast-path / 80.71 cascade (raw 87.34 / 86.60). Gevva0 rows scored with official composite scorer.
● Intelligence (chance-corrected)
0
Gevva0 cascade
44 ms p50 · local
vs
0
Claude Opus 4.6 Thinking
4,850 ms p50 · cloud
● Decision Index 0.3 (N=350)score · p50

Put a cascade in front of your LLM.

Apache 2.0. Runs on one local GPU. No API keys, no data leaving the building, no per-token bill. Decisions and streaming chat share a single loaded model, so you don't need a second copy in VRAM.

❯ uv sync
❯ uv run gevva0 serve --port 8000 # decision UI at /ui · chat at /chat
❯ uv run python demos/pacman/run.py
engine.decide() · stateless REST DecisionBridge · 60 FPS loops Tier0DecisionBridge · sub-3 ms Vision via mmproj
Act 1/10 ·
00:00 / 00:00
▶ Click to play · Space pause · ←/→ scenes · F fullscreen · N narrate