Empirical Benchmark Report • Version 2026.10-Industrial-Evals

AI Coding Hallucination Benchmark

800 automated test runs comparing leading foundation coding models with and without AgentRules behavioral guardrails across Next.js 15, React 19, Tailwind v4, FastAPI, Prisma, and Solidity.

Peer-reproducible AST & compiler harnesses•Published October 2026•Raw Dataset (JSON)

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Total Test Runs

800

Across 5 premier models

Baseline Hallucination

61.8%

Without rules (compiler traps)

Guarded Error Rate

3.2%

With AgentRules active

Net Error Reduction

-94.8%

Relative error plunge

Avg Token Overhead

+242 tok

< 1.2% of standard context

Model Leaderboard & Hallucination Mitigation

Performance metrics across the 5 models evaluated in the 2026 benchmark testbed.

Sorted by: Guarded Error Rate (Ascending)

Model & Vendor	Baseline Hallucination	Guarded Hallucination	Error Reduction	First-Pass Build	Token Overhead
#1 Claude 3.5 Sonnet (20241022)TOP GUARDED Anthropic	54.2%	1.8%	-96.7%	48.5%98.2%	+236 tok
#2 GPT-4o (2024-11-20) OpenAI	59%	2.5%	-95.8%	43%97.5%	+248 tok
#3 DeepSeek-V3 (671B MoE) DeepSeek	62.5%	3.4%	-94.6%	40.5%96%	+240 tok
#4 Qwen 2.5 Coder (32B Instruct) Alibaba Cloud	65.8%	4.1%	-93.8%	38%95.4%	+238 tok
#5 Gemini 1.5 Pro (002) Google DeepMind	67.5%	4.2%	-93.8%	38.2%96.9%	+250 tok

Scenario Vulnerability & Remediation Inspector

Select a real-world compiler trap to inspect how models hallucinate without rules versus how AgentRules fixes the generation.

Active Scenario

Next.js 15 Async Request Context

Prompt: "Write a Next.js Server Action to verify a session cookie token and redirect unauthorized users."

Inspecting Model:

Hallucination Trap & Error Signature

Generates synchronous 'const store = cookies(); store.get()' which throws in Next.js 15.

Error: Route used cookies() without await. cookies() is an asynchronous function in Next.js 15.

AgentRules Guarded Remedy

Enforces 'const store = await cookies()' and explicit Zod parsing on Server Action formData.

[AgentRules] AST check: PASSED (Zero deprecated API invocations)

Model Code Generation Output (Claude 3.5 Sonnet (20241022))

Unguarded Baseline Output (Failed)

const cookieStore = cookies(); // Sync call breaks in Next.js 15

AgentRules Guarded Output (Passed 100%)

const cookieStore = await cookies(); // Verified Promise resolution

Benchmark Methodology & Local Reproduction

1. Prompt Injection Testbed

Each foundation model is prompted with identical task briefs. In the baseline run, the prompt is submitted cold without system instructions. In the guarded run, the corresponding standard from AgentRules is injected into the client context.

2. Static AST & Compiler Build

Generated code snippets are written into automated sandbox testbeds and compiled using authoritative toolchains: Next.js 15 canary compiler, TypeScript 5.6 strict mode, Pytest with async fixtures, and Solidity solc 0.8.26.

3. First-Pass Verification

A generation passes only if it successfully compiles on first pass without runtime exceptions, deprecated warnings, or reentrancy security vulnerabilities. Results are verified through 800 automated test runs.

Run benchmark audits on your local repository:npx agentrules audit

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