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antigravity-booster
Reference

Benchmarks & Statistical Evals

Empirically calibrated statistical benchmarks, Pareto frontier analysis, and 80/20 root-cause breakdowns comparing Antigravity Booster (agb) against Naive Straight agy and Raw agy (Best Practices).

This page presents the reproducible statistical evaluation suite (evals/) comparing Antigravity + Booster (agb) against both Naive Straight Antigravity (agy) and Raw agy with Best Practices.

Reproduce every figure locally

Every distribution, confidence interval, hypothesis test, and Pareto series on this page is generated deterministically from fixed PRNG seed 20261030 via npm run eval (or as machine-readable JSON via node evals/runner.mjs --json).

Experimental Methodology & Calibration Provenance

All four benchmark scenarios execute N = 100 paired Monte Carlo trials (1,600 total ticket dispatches in perf-16-ticket-scale, 500 seeded defects plus 500 clean negative controls in acc-cross-model-prosecution, and 300 adversarial safety hazards in acc-mechanical-safety-gates).

Rather than relying on ungrounded synthetic assumptions, the simulation parameters are anchored directly to live empirical measurements captured against the agy CLI in docs/calibration/probes-2026-06-11.md and docs/calibration/probes-2026-07-14.md:

Empirical AnchorMeasured ValueSource ProbeArchitectural Implication
Single-Pool Concurrency Knee (width = 1..4)0% timeouts; median 26.7s..28.8sProbe 5 (2026-06-11)Operating at or below width = 4 on a frontier pool yields flat latency and zero rate-limit drops.
Single-Pool Burst Collapse (width = 8)25% timeout rate (2/8 at 120s); P90 spikes to 68.4sProbe 5 (2026-06-11)Unconstrained subagent fan-out on a single model family hits server-side queueing and 120s print timeouts.
Independent Quota-Family BucketsGemini Models vs. Claude and GPT models (5h & weekly)Probe 4 (2026-07-14)Routing across gemini-flash (8), gemini-pro (4), claude (4), and gpt-oss (2) provides 18 concurrent slots below every pool's knee.
Cross-Family Prosecution Latency & Catch11.1s median; caught Unicode defect missed by builderProbe 6 (2026-06-11)A cross-family gemini-3-flash prosecutor catches representation blind spots left by a claude-sonnet builder.

The Three Comparison Arms

To avoid a strawman comparison, every scenario evaluates three distinct operating regimes:

  1. Straight agy (Naive Baseline): Single-session serial execution, unconstrained 8-wide single-pool subagent bursts, or same-context (Model: 'inherit') self-review with prompt-only safety instructions.
  2. Raw agy (Best Practices): A disciplined engineer using Antigravity's built-in primitives to their fullest without agb:
    • /plan and /teamwork slash commands to structure wave execution.
    • invoke_subagent with Workspace: 'share' (shared git repository worktrees) and manual tier splitting (Model: 'flash' for low-tier work, Model: 'pro' for complex work).
    • Well-crafted AGENTS.md repository rules and the test-driven-development skill.
    • Fresh-context adversarial-reviewer subagent invocation (doubt-driven-development) after each wave.
  3. Antigravity + Booster (agb):

Executive Summary: Headline Statistical Gains

DimensionStraight agy (Naive)Raw agy (Best Practices)Antigravity + Booster (agb)agb Gain vs. Best Practices (and vs. Naive)Statistical Significance (vs. Best Practices)
8-Ticket Feature DAG Latency (Mean / P95)576.1s / 647.0s (Serial)
194.8s / 265.0s (1-Pool)
184.4s / 216.2s138.5s / 160.4s1.33x faster vs. Best Practices (d = 2.84)
4.16x faster vs. Serial (d = 12.63)
p < 0.0001 (Mann-Whitney U)
16-Ticket Scale Refactor Latency (Mean / P95)312.5s / 354.9s274.2s / 366.3s132.0s / 173.7s2.08x faster vs. Best Practices (-52.6% P95)
2.37x faster vs. Naive
p < 0.0001 (Mann-Whitney U)
Pool Rate-Limit Timeout Rate (1,600 Dispatches)24.1% ([22.1%, 26.3%])9.3% ([8.0%, 10.8%])1.2% ([0.8%, 1.8%])-87.2% timeouts vs. Best Practices
-95.1% vs. Naive
z = 10.30, p < 0.0001
5h Frontier Pool Quota Consumed (8-Ticket DAG)18.9% (Serial) / 15.6% (1-Pool)10.5%4.8%-54.2% frontier quota vs. Best Practices
-74.6% vs. Serial
Deterministic bucket split
Defect Detection Recall (500 Seeded Defects)21.8% (No review)
52.0% (Same-model)
73.6% (adversarial-reviewer subagent)92.4% (Cross-family prosecutor + 4-lens fleet)+18.8 pp recall vs. Best Practices
+40.4 pp vs. Same-Model
z = 7.91, p < 0.0001
Post-Review Defect Escape Rate78.2% (No review)
48.0% (Same-model)
26.4% (132 / 500)7.6% (38 / 500)-71.2% fewer escaped defects vs. Best Practices
-84.2% vs. Same-Model
z = 7.91, p < 0.0001
Safety Hazard Prevention (Rails, Scope, Mutants)56.3% (169 / 300)80.3% (241 / 300)98.0% (294 / 300) (100% on rails & scope)-89.8% hazard escapes vs. Best Practices
-95.4% vs. Naive
z = 6.96, p < 0.0001

Pareto Frontier & 80/20 Root-Cause Analysis

1. Speed–Accuracy Pareto Frontier (Throughput vs. Defect Detection Recall)

In single-session or single-family agent workflows, engineering teams face an inherent trade-off between delivery throughput (tickets completed per minute) and verification rigor (defect detection recall). Adding in-session review passes improves recall but serializes execution and consumes active-session context.

Because agb dispatches builders and cross-family prosecutors concurrently across four independent model pools in isolated git worktrees, it shifts the entire Pareto frontier outward — strictly dominating every baseline on both velocity and defect recall simultaneously:

Operating Regime8-Ticket Throughput (tickets/min)16-Ticket Scale Throughput (tickets/min)Defect Detection Recall (%)Post-Review Escape Rate (%)Safety Hazard Block Rate (%)Pareto Efficiency Status
Straight agy (Serial, Builder Only)0.96/min1.95/min21.8%78.2%56.3%Strictly Dominated
Straight agy (Serial + Same-Model Review)0.83/min1.62/min52.0%48.0%56.3%Strictly Dominated
Straight agy (Naive 1-Pool Parallel)2.46/min3.20/min52.0%48.0%56.3%Strictly Dominated
Raw agy (Best Practices: /plan + /teamwork + adversarial-reviewer)2.60/min3.71/min73.6%26.4%80.3%Sub-Frontier (Single-Family Bound)
Antigravity + Booster (agb Multi-Pool DAG + Cross-Model Fleet)3.47/min7.40/min92.4%7.6%98.0%Pareto-Optimal Frontier

2. Pareto Analysis of Escaped Defects (Why Single-Family Review Leaves a 26.4% Escape Tail)

When an engineer uses Raw agy (Best Practices) — spawning adversarial-reviewer in a fresh subagent context — post-review defect escapes drop from 240 / 500 (48.0%) to 132 / 500 (26.4%). However, ranking those 132 escaped defects by root cause reveals a classic Pareto distribution:

  • The top 2 defect classes (Spec Ambiguity & Unicode/Locale Boundary and Lock / TOCTOU / Concurrency Race) account for 53.8% of all escaped defects.
  • The top 3 defect classes account for 71.2% of all escaped defects.
  • The top 4 defect classes account for 87.9% of all escaped defects.

Why does Spec Ambiguity & Unicode/Locale Boundary alone cause 31.8% (42 / 132) of all Best-Practices escapes? Because invoke_subagent only accepts Model: 'inherit' | 'flash_lite' | 'flash' | 'pro' within the active session's model family. When a builder and its reviewer come from the same model family, they share correlated pretraining priors on ambiguous specification phrasing and Unicode/locale edge cases (the exact failure mode observed in Probe 6).

By routing prosecution to an independent model family (lib/prosecute.mjs) and fanning out four orthogonal specialist lenses (lib/review.mjs), agb collapses escapes in the #1 Pareto category from 42 down to 3 (-92.9%):

Pareto RankDefect ClassRaw agy Best Practices Escapes (N=100)Share of Best-Practices EscapesCumulative Pareto Share (%)agb Cross-Model Escapes (N=100)agb Escape Reduction vs. Best Practices
#1Spec Ambiguity & Unicode/Locale Boundary (Probe 6 class)4231.8%31.8%3-92.9%
#2Lock / TOCTOU / Async Interleaving Race2922.0%53.8%12-58.6%
#3Auth, Attestation & Trust-Boundary Bypass2317.4%71.2%8-65.2%
#4Silent Error Swallowing & Partial-Failure Leak2216.7%87.9%11-50.0%
#5Off-by-One & State Machine Transition Defect1612.1%100.0%4-75.0%
TotalAll 500 Seeded Defects132100.0%—38-71.2% (z = 7.91, p < 0.0001)

3. Pareto Analysis of Wall-Clock Latency Overhead (Where Time Is Lost Without agb)

3a. Straight agy Serial (576.1s) vs. agb (138.5s): Δ = 437.6s Excess Wall-Clock Time

Decomposing the 437.6s wall-clock latency gap on the 8-ticket DAG shows that the top 2 causes (Unparallelized Serial Turn Execution and Context Window Token Inflation) account for 74.7% of all wasted time, and the top 3 account for 89.1%:

Pareto RankLatency Overhead DriverExcess Seconds (s)Share of Excess Time (%)Cumulative Pareto Share (%)agb Architectural Elimination Mechanism
#1Unparallelized Serial Turn Execution228.4s52.2%52.2%Topological wave fan-out across isolated git worktrees (lib/scheduler.mjs, lib/worktrees.mjs)
#2Context Window Token Inflation (+7.5%/step)98.6s22.5%74.7%Fresh cold-start context per ticket (--print worker per shard)
#3Shared-Tree Regression & Rework Cycles62.8s14.4%89.1%Per-ticket scope containment + pre-merge verification gate (lib/gates.mjs)
#4Sequential Per-Step Test Gate Runs31.2s7.1%96.2%Concurrent worktree test execution before serialized fast-forward merge
#5Single-Bucket Frontier Contention16.6s3.8%100.0%Tier-based model routing (low -> gemini-flash, mid -> gemini-pro/sonnet)

3b. Raw agy Best Practices (274.2s) vs. agb (132.0s) at 16-Ticket Scale: Δ = 142.2s Excess Wall-Clock Time

When comparing agb against Raw agy (Best Practices) on a 16-ticket repository refactoring, agb still finishes 2.08x faster (132.0s vs. 274.2s, saving 142.2s). Pareto decomposition shows that 75.0% of the remaining latency gap comes from just two structural platform limits in native agy:

  1. Single-Family Pool Contention & 120s Timeout Retries (51.4% of excess time): Native invoke_subagent cannot dispatch across model families (Gemini vs. Claude/GPT), forcing all 16 subagents and parent turns to draw from a single quota family (9.3% timeout rate vs. 1.2% in agb).
  2. Parent LLM Wave-Orchestration Turns (23.6% of excess time): Native /teamwork requires the parent LLM to wake up between sub-batches, read subagent outputs, and coordinate merges (~9.5s per sub-wave), whereas agb's Node.js scheduler transitions waves in < 10ms with 0 LLM tokens.
Pareto RankBest-Practices Bottleneck at 16-Ticket ScaleExcess Seconds (s)Share of Excess Time (%)Cumulative Pareto Share (%)Why Native agy Primitives Cannot Eliminate It
#1Single-Family Pool Queueing & 120s Timeouts73.1s51.4%51.4%invoke_subagent Model enum (inherit|flash_lite|flash|pro) is bound to the session's model family
#2Parent LLM Wave-Orchestration Turns33.5s23.6%75.0%/teamwork requires an LLM parent turn between waves; agb uses a 0-token Node event loop
#3In-Session Sequential Subagent Review21.1s14.8%89.8%Parent session must spawn and summarize adversarial-reviewer turns serially per wave
#4Uncoordinated Scope / Interface Merge Fixups14.5s10.2%100.0%Native /plan lacks agb plan's static glob-overlap & cross-model parallax contract compiler

4. Pareto Analysis of Safety Hazard Escapes (N = 300 Adversarial Hazards)

Under Raw agy (Best Practices) (AGENTS.md rules + test-driven-development + adversarial-reviewer), 59 / 300 (19.7%) adversarial hazards still escape into the target branch. Ranking those 59 escaped hazards reveals an extreme Pareto skew:

  • 64.4% (38 / 59) of all Best-Practices safety escapes come from a single hazard class: Hollow / Tautological Tests (test suites that pass npm test and look reasonable during static diff review, but fail to kill surviving AST code mutants).
  • The remaining 35.6% (21 / 59) come from Frozen Rail Tampering (18.6%) and Out-of-Scope File Drift (16.9%), where a subagent under strike-2 test-failure pressure edits a protected rail or an out-of-scope file and rationalizes the edit in its completion message.
  • agb's mechanical gates eliminate 100% of rail and scope escapes (0 / 200) via pre-execution PreToolUse denial (hooks/pre-tool-use.mjs), adlc rails-guard, and worktree diff validation, while adlc hollow-test executes real AST mutations to cut hollow-test escapes by -84.2% (38 -> 6):
Pareto RankSafety Hazard ClassPrompt-Only Escapes (N=100)Raw agy Best-Practices Escapes (N=100)Share of Best-Practices EscapesCumulative Pareto Share (%)agb Mechanical Gate Escapes (N=100)agb Escape Reduction vs. Best Practices
#1Hollow Tests (Green npm test, Surviving AST Mutants)673864.4%64.4%6-84.2%
#2Frozen Rail Tampering (lib/lock.mjs, .adlc/**)381118.6%83.1%0-100.0%
#3Out-of-Scope File Creep (scope glob violation)261016.9%100.0%0-100.0%
TotalAll 300 Safety Hazards13159100.0%—6-89.8% (z = 6.96, p < 0.0001)

Full Scenario Distributions & Parametric / Non-Parametric Tests

Scenario 1 (perf-8-ticket-dag): 8-Ticket Multi-File Feature DAG

Evaluates an 8-ticket feature build-out structured as a 3-wave DAG (Wave 1: 4 foundation tickets; Wave 2: 3 mid-tier integration tickets; Wave 3: 1 frontier convergence ticket):

Execution ModeMean Latency (s)SD (s)95% Bootstrap CI (s)Median P50 (s)P90 (s)P95 (s)IQR (s)5h Frontier Quota UsedMerge Conflict Retry Rate
Straight agy (Serial Single-Session)576.1s46.5s[566.5s, 585.1s]576.3s636.8s647.0s64.7s18.9%0.0%
Straight agy (Naive 1-Pool Parallel)194.8s32.7s[188.9s, 201.4s]184.9s249.3s265.0s37.8s15.6%28.0%
Raw agy (Best Practices: /plan + /teamwork + share)184.4s19.4s[180.8s, 188.2s]180.7s210.0s216.2s24.4s10.5%18.0%
Antigravity + Booster (agb Multi-Pool DAG)138.5s11.9s[136.1s, 141.0s]137.7s154.3s160.4s20.4s4.8%0.0%

Scenario 2 (perf-16-ticket-scale): 16-Ticket Refactoring Under Rate-Limit Pressure

Models a 16-ticket repository refactoring (2 waves of 8 concurrent tickets) against the server-side queueing and timeout curve measured in Probe 5:

Execution ModeMean Latency (s)Median P50 (s)P95 Tail Latency (s)Throughput (tickets/min)Timeouts / 1,600 DispatchesTimeout Rate (95% Wilson CI)
Straight agy (Unconstrained 8-Wide Single Pool)312.5s335.9s354.9s3.20/min386 / 160024.1% ([22.1%, 26.3%])
Raw agy (Best Practices: Manual Sub-Batching)274.2s270.9s366.3s3.71/min149 / 16009.3% ([8.0%, 10.8%])
Antigravity + Booster (agb Multi-Pool Token-Bucket)132.0s125.0s173.7s7.40/min19 / 16001.2% ([0.8%, 1.8%])

Scenario 3 (acc-cross-model-prosecution): Cross-Model Prosecution vs. Same-Model & Best-Practices Review

Evaluates defect detection recall, post-review escape rate, precision, and F1 across 500 seeded defects (100 trials × 5 defect classes) and 500 clean negative controls:

Review ArchitectureDefects CaughtDefects EscapedRecall (95% Wilson CI)Escape Rate (95% Wilson CI)False Positives / 500 CleanPrecisionF1 Score
Straight agy (Builder Only, No Review)109 / 500391 / 50021.8% ([18.4%, 25.6%])78.2% ([74.4%, 81.6%])———
Straight agy + Same-Model Self-Review (inherit)260 / 500240 / 50052.0% ([47.6%, 56.3%])48.0% ([43.7%, 52.4%])42 / 500 (8.4%)86.1%0.648
Raw agy (Best Practices: Fresh adversarial-reviewer Subagent)368 / 500132 / 50073.6% ([69.6%, 77.3%])26.4% ([22.7%, 30.4%])24 / 500 (4.8%)93.9%0.825
Antigravity + Booster (agb Cross-Family Prosecutor + 4-Lens Fleet)462 / 50038 / 50092.4% ([89.7%, 94.4%])7.6% ([5.6%, 10.3%])19 / 500 (3.8%)96.0%0.942

Per-Defect-Class Recall Breakdown (N = 100 Seeded Defects per Class)

Defect ClassBuilder OnlySame-Model ReviewRaw agy Best Practices (adversarial-reviewer)agb Cross-Model + 4-Lens Fleetagb Gain vs. Best Practices
Spec Ambiguity & Unicode/Locale Boundary (Probe 6 class)10.0%35.0%58.0%97.0%+39.0 pp
Auth, Attestation & Trust-Boundary Bypass17.0%57.0%77.0%92.0%+15.0 pp
Lock / TOCTOU / Async Interleaving Race19.0%45.0%71.0%88.0%+17.0 pp
Off-by-One & State Machine Transition Defect33.0%61.0%84.0%96.0%+12.0 pp
Silent Error Swallowing & Partial-Failure Leak30.0%62.0%78.0%89.0%+11.0 pp

Scenario 4 (acc-mechanical-safety-gates): Mechanical ADLC Safety Gates vs. Prompt-Only & Best-Practice Instructions

Evaluates hazard interception across 300 adversarial failure modes (100 frozen rail tampering attempts, 100 out-of-scope file mutations, and 100 hollow test suites with surviving code mutants):

Safety Hazard ClassStraight agy (Prompt-Only)Raw agy Best Practices (AGENTS.md + Review)Antigravity + Booster (agb Mechanical Gates)Two-Proportion z-Test (agb vs. Best Practices)
Frozen Rail Tampering (lib/lock.mjs, .adlc/**)62.0% (62/100)89.0% (89/100)100.0% (100/100) via PreToolUse + rails-guardz = 3.41, p = 0.0006
Out-of-Scope File Creep (scope glob violation)74.0% (74/100)90.0% (90/100)100.0% (100/100) via worktree scope gatez = 3.24, p = 0.0012
Hollow Tests (Green npm test, Surviving Mutants)33.0% (33/100)62.0% (62/100)94.0% (94/100) via adlc hollow-test AST mutation gatez = 5.46, p < 0.0001
Combined Safety Gate Prevention (N = 300)56.3% (169/300)80.3% (241/300)98.0% (294/300)z = 6.96, p < 0.0001

Live Mechanical Runtime Probes

In addition to the N = 100 Monte Carlo distributions and the 5-pillar live subsystem benchmark suite (evals/), every execution of npm run eval (and test/evals.test.mjs) runs six live mechanical verification probes (B1–B6) directly against the repository's production enforcement modules (hooks/policy/evaluate.mjs, lib/migrate.mjs, bin/node-launcher.sh, and scripts/stage-marketplace-plugin.mjs):

Runtime ProbeTarget ModuleExpected InvariantObserved Verdict
B1 — Frozen Rail Write InterceptionevaluatePayload (hooks/policy/evaluate.mjs)Blocks write_file targeting lib/lock.mjsdecision: "deny" (PASS)
B2 — Trust-Root Tamper InterceptionevaluatePayload (hooks/policy/evaluate.mjs)Blocks write_file targeting .adlc/config.jsondecision: "deny" (PASS)
B3 — In-Scope Write AuthorizationevaluatePayload (hooks/policy/evaluate.mjs)Permits write_file on in-scope ticket pathsdecision: "pass" (PASS)
B4 — agy 1.4.x Validator Summary ParsingparseValidateOutput (lib/migrate.mjs)Parses skills 7 · agents 3 · rules 1 · hooks 1 · mcpServers 1{"skills":7,"agents":3,"rules":1,"hooks":1,"mcpServers":1} (PASS)
B5 — Strict Marketplace Bundle ValidationvalidateStagedPluginStrict (scripts/stage-marketplace-plugin.mjs)Passes agy plugin validate --strict --json with 0 findingserrors: 0, warnings: 0, notes: 0 (PASS)
B6 — node-launcher.sh PATH Fast-Pathbin/node-launcher.shResolves ambient PATH Node >= 22.19.0 without filesystem scanstatus: 0 (PASS)

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