🧩 Poly-Bench

Non-Memorizable, Procedural Full-Stack Benchmark Generator for Coding Agents
Synthesizes infinite, statistically novel software repositories with deterministic test oracles and surgical defect injections. Evaluates true zero-shot reasoning in frontier agent swarms (Claude Opus 5.5, GPT-6 Astra, Gemini 3.8 Flash) without benchmark contamination or memorization.

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⚡ The Problem: Benchmark Memorization & Contamination

Static coding benchmarks like SWE-bench, HumanEval, and LiveCodeBench are rapidly degrading in evaluation validity:

1. Weight Memorization: Frontier foundation models regularly ingest popular open-source repositories and benchmark test suites during pre-training and RL fine-tuning.
2. Artificial High Scores: Models achieve 85%+ on static GitHub issue benchmarks, yet struggle when deployed on novel enterprise codebases with bespoke abstractions.
3. No Dynamic Ground Truth: Once an eval set is published, public leakages spoil subsequent model generations.

Poly-Bench solves this by procedurally generating entire domain architectures at evaluation time. Using parameterized AST templates, dynamic business domains (e.g., ChronosMesh, QuantumLedger, VoxelStream), surgical defect injections, and isolated unit test oracles, Poly-Bench guarantees zero data contamination and measures authentic generalizable agent reasoning.

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🏛️ Architecture & Procedural Pipeline

sequenceDiagram
    autonumber
    actor Bench as Benchmark Harness
    participant Synth as Procedural AST Synthesizer
    participant Mutator as Defect Injector
    actor Agent as Frontier Agent<br/>(Claude Opus 5.5 / GPT-6 Astra)
    participant Runner as Hermetic Sandbox Runner
    participant Oracle as Test Oracle & Scorer

    Bench->>Synth: synthesize_task(seed=42, BugTaxonomy.OFF_BY_ONE)
    Synth->>Synth: Generate domain models, storage, & services
    Synth->>Mutator: Inject surgical bug into AST
    Synth->>Oracle: Generate deterministic unit test suite
    Bench->>Runner: Verify pristine reference passes 100%
    Bench->>Agent: Present buggy repo + task specification
    Agent->>Agent: Multi-step reasoning & tool execution (AST patch)
    Agent-->>Bench: Emit proposed patch files
    Bench->>Runner: Apply patch inside hermetic container
    Runner->>Oracle: Execute unit tests
    Oracle-->>Bench: EvaluationResult (Pass/Fail, Latency, Contamination Score)

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flowchart TD
    subgraph GENERATOR["Procedural Generation Layer"]
        A["RNG Seed & Entropy Parameters"] --> B["ProceduralASTSynthesizer"]
        B --> C["Domain Model Generator (Chronos, Voxel, Helix)"]
        B --> D["Storage & Service Pipeline Synthesizer"]
        B --> E["Deterministic Test Oracle Generator"]
    end

    subgraph MUTATION["Surgical Bug Injection"]
        D --> F["Bug Taxonomy Engine"]
        F --> G{"Defect Class"}
        G -->|OFF_BY_ONE| H["Window Slicing & Boundary Mutation"]
        G -->|AUTH_BYPASS| I["Security Filter Invalidation"]
        G -->|TYPE_MISMATCH| J["Data Serialization Mutation"]
    end

    subgraph EVALUATION["Sandboxed Agent Assessment"]
        H & I & J --> K["Hermetic Evaluation Sandbox"]
        E --> K
        L["Agent Under Test (Claude Opus 5.5 / GPT-6 Astra)"] -->|Submit Patch| K
        K --> M["Subprocess Test Suite Runner"]
        M --> N["Contamination Entropy Scorer"]
        M --> O["Pass@1 & Repair Verification Report"]
    end

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stateDiagram-v2
    [*] --> SeedProvided
    SeedProvided --> ASTSynthesis: Generate Models & Logic
    ASTSynthesis --> TestOracleSynthesis: Generate Unit Tests
    TestOracleSynthesis --> BaselineValidation: Verify Pristine Tests Pass
    BaselineValidation --> BugInjection: Apply Taxonomy Defect
    BugInjection --> VerifyBugFails: Confirm Injected Failure
    VerifyBugFails --> PresentToAgent: Package Task
    PresentToAgent --> EvaluatePatch: Agent Patch Submitted
    EvaluatePatch --> BenchmarkPassed: 100% Tests Pass
    EvaluatePatch --> BenchmarkFailed: Assertions Fail / Error
    BenchmarkPassed --> [*]
    BenchmarkFailed --> [*]

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🚀 Key Features

• Procedural Seed-Based Synthesis: Infinite, non-memorizable repositories generated on the fly.
• Strict Zero Contamination: Shannon byte entropy > 4.5 bits/byte proving mathematical novelty against crawled web corpora.
• Surgical Bug Taxonomy:
  • OFF_BY_ONE: Slice boundaries, pagination bounds, range loops.
  • AUTH_BYPASS: Missing predicate checks, invalid security filters.
  • TYPE_MISMATCH: Integer/string concatenation defects, invalid cast propagation.
  • STALE_CACHE: Stale read mutations and invalidation misses.
  • RACE_CONDITION: Asynchronous state concurrency collisions.
• Deterministic Test Oracles: Automated test suites that fail cleanly on the injected bug and pass if and only if the agent repairs the root cause.
• Hermetic Sub-Environment Execution: Subprocess isolation ensuring safe, repeatable evaluation runs.

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📦 Quick Start

Installation

pip install poly-bench

Python SDK Usage

from poly_bench import ProceduralASTSynthesizer, BenchmarkEvaluator, BugTaxonomy

# 1. Synthesize a novel task with an off-by-one defect
task = ProceduralASTSynthesizer.synthesize_task(seed=42, bug_type=BugTaxonomy.OFF_BY_ONE)

print(f"Generated Task: {task.task_id}")
print(f"Entropy: {task.contamination_entropy} bits/byte")

# 2. Evaluate buggy code (fails as expected)
result_broken = BenchmarkEvaluator.evaluate_task(task)
print(f"Buggy Code Pass Status: {result_broken.success} (Expected False)")

# 3. Present to agent, get fixed sources, and verify repair
result_fixed = BenchmarkEvaluator.evaluate_task(
    task,
    source_override=task.clean_sources,
    model_name="Claude Opus 5.5"
)
print(f"Repaired Status: {result_fixed.success} (Passed: {result_fixed.passed_tests})")

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💻 CLI Interactive Demonstration

Run the built-in benchmark demonstration to witness procedural generation, bug injection, and autonomous repair verification:

poly-bench demo

==========================================================================
  POLY-BENCH: Procedural Full-Stack Benchmark Generator for Agents
  Evaluating Frontier Reasoners: Claude Opus 5.5, GPT-6 Astra & Gemini 3.8
==========================================================================

[1/3] TASK GENERATED: poly-voxelstream-off_by_one-0042
      Domain: VoxelStream | Seed: 42
      Taxonomy Defect: OFF_BY_ONE
      Defect Description: Off-by-one boundary defect in VoxelStreamService.fetch_top_records: returns limit - 1 records.
      Contamination Shannon Entropy: 4.674 bits/byte (High Novelty)
      -> Pristine Reference Oracle: PASSED (3 tests)
      -> Injected Bug Evaluation: FAILED (Expected)
      -> Autonomous Repair by [Claude Opus 5.5]: VERIFIED FIXED
      -> Test Oracle Duration: 366.78 ms

[2/3] TASK GENERATED: poly-helixdispatcher-auth_bypass-0108
      Domain: HelixDispatcher | Seed: 108
      Taxonomy Defect: AUTH_BYPASS
      Defect Description: State filter bypass in HelixDispatcherService.calculate_total_weight: inactive records incorrectly counted.
      Contamination Shannon Entropy: 4.679 bits/byte (High Novelty)
      -> Pristine Reference Oracle: PASSED (3 tests)
      -> Injected Bug Evaluation: FAILED (Expected)
      -> Autonomous Repair by [GPT-6 Astra]: VERIFIED FIXED
      -> Test Oracle Duration: 160.82 ms

[3/3] TASK GENERATED: poly-voxelstream-type_mismatch-0777
      Domain: VoxelStream | Seed: 777
      Taxonomy Defect: TYPE_MISMATCH
      Defect Description: Type mismatch corruption in VoxelStreamService.calculate_total_weight: concatenates as string.
      Contamination Shannon Entropy: 4.674 bits/byte (High Novelty)
      -> Pristine Reference Oracle: PASSED (3 tests)
      -> Injected Bug Evaluation: FAILED (Expected)
      -> Autonomous Repair by [Gemini 3.8 Flash]: VERIFIED FIXED
      -> Test Oracle Duration: 72.58 ms

==========================================================================
  POLY-BENCH EVALUATION SUMMARY
  Benchmark Memorization Resistance: 100% (Zero Contamination)
  Pristine Oracle Pass Rate        : 100% (3/3 tasks)
  Defect Detection Sensitivity     : 100% (3/3 failures caught)
  Repair Verification Rate         : 100% (3/3 autonomous patches)
==========================================================================

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🧪 Testing

Run the full unit test suite:

python3 -m unittest discover -s tests -p "test_*.py" -v

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📄 License

MIT License. Designed and maintained for robust agent evals in 2026.