nasde-benchmark-creator

name

nasde-benchmark-creator

description

Create coding agent benchmarks for evaluation with nasde. Use this skill when the user wants to: - Create a new benchmark project (set of tasks for evaluating coding agents) - Add tasks to an existing benchmark - Create or modify agent variants (configurations that control agent behavior) - Set up assessment dimensions and scoring criteria - Verify that a new benchmark's Docker environment and tests work Even if the user doesn't say "benchmark" — if they're talking about creating coding challenges for AI agents or setting up evaluation criteria, this skill applies.

NASDE Benchmark Creator

Create and configure coding agent benchmarks for evaluation with nasde. A benchmark is a set of coding tasks that AI agents solve inside isolated Docker containers, scored both by functional tests (pass/fail) and by an LLM-as-a-Judge architecture assessment.

Critical: line endings on Windows (read this first)

Benchmark scripts execute inside Linux sandboxes (Docker, Daytona). If tests/test.sh, solution/solve.sh, or environment/Dockerfile are checked out with CRLF line endings (the Windows git default when core.autocrlf=true and there is no .gitattributes), every trial fails immediately with:

bash: line 1: /tests/test.sh: cannot execute: required file not found

…because the kernel reads the shebang as #!/bin/bash\r and tries to execute a non-existent /bin/bash\r. The agent finishes its work, but the verifier never runs and Harbor reports RewardFileNotFoundError.

Mitigation (always do this for a new benchmark — nasde init does it for you, but verify):

1. The benchmark repo MUST have a .gitattributes file enforcing LF for shell scripts and Dockerfiles. The minimum content:

   * text=auto eol=lf
   *.sh        text eol=lf
   *.bash      text eol=lf
   Dockerfile  text eol=lf
   *.dockerfile text eol=lf
   docker-compose.yaml text eol=lf
   docker-compose.yml  text eol=lf
   
   *.ps1       text eol=crlf
   *.bat       text eol=crlf
   *.cmd       text eol=crlf
   

   nasde init writes this automatically. If you are adding a benchmark to an existing repo without .gitattributes, create one before adding any task.

2. When writing .sh or Dockerfile content programmatically on Windows, write with explicit LF — not path.write_text(content) (which translates \n→\r\n on Windows), but path.write_text(content, encoding="utf-8", newline="") or open the file in binary mode.

3. After committing on Windows for the first time, run:

   git add --renormalize .
   git commit -m "normalize line endings"
   

   to fix any files that landed before .gitattributes was in place.

4. Sanity check before pushing a new task:

   file tasks/<task>/tests/test.sh
   # MUST say "with LF line terminators" or omit line-terminator info entirely.
   # If it says "with CRLF line terminators" — fix it (`sed -i 's/\r$//' file`).
   

This applies equally when you're adding tasks to a benchmark someone else created — if their repo has no .gitattributes and you're on Windows, your contribution will silently break for them on Linux CI and vice versa.

Step 1: Understand what to evaluate

Before creating files, clarify with the user:

• What programming language/framework? (determines Dockerfile base image)
• What kind of coding challenges? (feature implementation, refactoring, bug fixing, etc.)
• What source repository should the agent work on? (git URL cloned in Dockerfile)
• What quality dimensions should be assessed? (these are benchmark-specific, not hardcoded)

Step 2: Scaffold or create the project

For a new benchmark, run:

nasde init my-benchmark --name my-benchmark

This creates the base structure. Then customize the generated files.

For adding tasks to an existing benchmark, skip to Step 4.

Step 3: Define assessment dimensions

Edit assessment_dimensions.json. Each benchmark has its OWN dimensions — design them for what matters in this benchmark's domain.

Examples by domain:

• Refactoring: code_clarity, test_preservation, api_compatibility, performance_impact
• API integration: error_handling, api_usage_correctness, test_coverage, documentation
• Security: vulnerability_detection, fix_correctness, regression_safety, explanation_quality
• DDD: domain_modeling, architecture_compliance, extensibility, test_quality

Rules:

• Pick whatever number of dimensions actually captures the quality you care about — there is no required minimum or maximum.
• Each dimension declares its own max_score (any positive integer). Scales are independent — a coarse pass/fail-ish dimension can be 0–3 while a richly graded one can be 0–50 in the same rubric. There is no requirement for the total to sum to 100. normalized_score is computed automatically from the actual sum of max_score values. See ADR-008.
• Names in snake_case
• Each dimension has: name, title, max_score, description

Step 4: Create task files

Each task lives in tasks/<task-name>/ and needs these files:

task.toml (required — single task config)

Single config file per task, shared with Harbor. nasde-specific fields live under [nasde.*].

version = "1.0"

[task]
name = "<benchmark-name>/<task-name>"   # Harbor requires org/name format
description = "Brief description"

[metadata]
difficulty = "intermediate"
language = "C#"
framework = ".NET 8"
domain = "E-Commerce"

[agent]
timeout_sec = 1800          # Primary agent timeout. Rule of thumb: estimated_time_minutes × 60.

[environment]
memory_mb = 4096            # Container memory limit. Claude Code needs 4096+, default 2048 is too low.

[verifier]
timeout_sec = 300           # Timeout for tests/test.sh.

[nasde.source]              # Only needed when task has no environment/Dockerfile (nasde auto-generates one).
git = "https://github.com/org/repo.git"
ref = "main"

Timeout priority: --timeout CLI flag > task.toml [agent] timeout_sec > Harbor default. Timeouts are per-task — there is no project-wide default in nasde.toml.

instruction.md (required)

Agent-facing task description. Structure it as:

# Task: <Name>

## Context
Working environment, codebase location (/app), technology stack.

## Requirement
What the agent must implement/fix/change. Concrete examples with inputs and expected outputs.

## Scope
What's in scope, what's not.

## Quality Expectations
Architecture and code quality expectations.

## Success Criteria
Numbered list matching what test.sh verifies.

## Constraints
What the agent must NOT do (e.g., don't modify existing tests).

environment/Dockerfile (required)

Reminder for Windows authors: the Dockerfile and any helper scripts it COPYs in must have LF line endings — Docker tolerates CRLF in some commands but not in RUN shell snippets, and any shell script copied with CRLF will hit the same shebang failure as test.sh.

FROM <base-image>

RUN apt-get update && apt-get install -y git curl wget ca-certificates && rm -rf /var/lib/apt/lists/*

WORKDIR /app
RUN git clone <repository-url> .

# Pre-install dependencies so the agent doesn't waste time
RUN <dependency-install-command>

# Verify the environment works
RUN <build-or-compile-command>

CMD ["/bin/bash"]

The Dockerfile MUST be self-contained — the agent starts working immediately.

tests/test.sh (required — Harbor verifier)

Reminder for Windows authors: this file MUST be saved with LF line endings. See "Critical: line endings on Windows" at the top of this skill. CRLF here = bash: required file not found and a wasted trial.

#!/bin/bash
cd /app

echo "Step 1: Verifying build..."
if <build-command>; then
    echo "✓ Build succeeded"
else
    echo "✗ Build failed"
    echo 0 > /logs/verifier/reward.txt
    exit 1
fi

echo "Step 2: Running tests..."
if <test-command>; then
    echo "✓ Tests pass"
else
    echo "✗ Tests failed"
    echo 0 > /logs/verifier/reward.txt
    exit 1
fi

echo "EVALUATION PASSED ✓"
echo 1 > /logs/verifier/reward.txt
exit 0

Rules:

• Every failure: echo 0 > /logs/verifier/reward.txt + exit 1
• Final success: echo 1 > /logs/verifier/reward.txt + exit 0
• Order steps from fundamental (build) to specific (implementation checks)

assessment_criteria.md (required for LLM-as-a-Judge evaluation)

Per-task rubric. Structure:

# Assessment Criteria: <Task Name>

Evaluate across N dimensions. Each dimension uses its own scale (0–`max_score`),
defined in `assessment_dimensions.json`. The ladder below shows what each score
means for one specific dimension — repeat for each dimension.

## 1. <Dimension Name> (0–<max_score>)

| Score | Criteria |
|-------|----------|
| 0           | <worst case> |
| <middle>    | <middle case> |
| <max_score> | <best case> |

**Key checks:**
- Specific things to look for

Pick a max_score that matches the granularity you can actually distinguish. A coarse pass/fail-ish dimension might be 0–3; a richly graded one might be 0–50. Choose the resolution per dimension, independently.

solution/solve.sh (optional)

Reference solution for verifying test.sh works. Not executed by Harbor.

Step 5: Create variants

Each variant is a directory under variants/<variant-name>/ with a required variant.toml declaring the agent type.

variant.toml (required)

agent = "claude"   # or "codex" or "gemini"

For Codex variants, always set the model explicitly to avoid inheriting the Claude model from nasde.toml:

agent = "codex"
model = "gpt-5.3-codex"   # Required for Codex — use an OpenAI model ID

Codex models (recommended first, as of 2026-03):

• gpt-5.4 — flagship frontier model, best overall for professional work
• gpt-5.4-mini — fast, efficient mini model for responsive coding and subagents
• gpt-5.3-codex — industry-leading coding model for complex software engineering
• gpt-5.3-codex-spark — near-instant real-time coding iteration (ChatGPT Pro only)
• Older: gpt-5.2-codex, gpt-5.1-codex, gpt-5-codex, gpt-5-codex-mini

Without model in variant.toml, Codex inherits nasde.toml's default (e.g. claude-sonnet-4-6), which silently produces garbage results.

For Gemini CLI variants, always set the model with the google/ prefix:

agent = "gemini"
model = "google/gemini-3-flash-preview"   # Required format: google/<model-name>

Gemini models (recommended first, as of 2026-03):

• google/gemini-3.1-pro-preview — advanced thinking model, best for deep reasoning
• google/gemini-3-flash-preview — best quality/speed ratio, daily coding tasks
• google/gemini-3.1-flash-lite-preview — fastest, simple and repetitive tasks

Scoping a variant to specific tasks (optional)

If a variant only makes sense for certain tasks — e.g. a skill whose examples are tuned to one repo's conventions — declare a tasks list. It restricts the variant to those tasks so --all-variants never runs it against the wrong codebase:

agent = "claude"
model = "claude-sonnet-4-6"
tasks = ["my-benchmark/task-a"]   # only runs against these tasks

Omit tasks for a general-purpose variant (the default — runs against all tasks). The scope wins even over an explicit --tasks filter.

Claude Code variant

variants/vanilla/
  variant.toml       # agent = "claude"
  CLAUDE.md          # Instructions (injected to /app/CLAUDE.md)
  skills/            # Optional: skill snapshots (injected to /app/.claude/skills/)

Codex variant

variants/codex-baseline/
  variant.toml       # agent = "codex"
  AGENTS.md          # Instructions (injected to /app/AGENTS.md)
  agents_skills/     # Optional: skill snapshots (native injection -> $HOME/.agents/skills/)
    my-skill/
      SKILL.md       # MUST start with --- YAML frontmatter (name + description)

Gemini CLI variant

variants/gemini-baseline/
  variant.toml       # agent = "gemini"
  GEMINI.md          # Instructions (injected to /app/GEMINI.md)
  gemini_skills/     # Optional: skill snapshots (native injection -> ~/.gemini/skills/)
    my-skill/
      SKILL.md       # MUST start with --- YAML frontmatter (name + description)

Codex/Gemini skills are registered natively (Harbor config.agent.skills), not via sandbox_files — these CLIs auto-discover skills only from a HOME-scoped dir, never from a /app cwd dir. This applies to all ways a skill is supplied to a Codex/Gemini variant: the agents_skills/ / gemini_skills/ snapshot above, a [[skill]] by-reference entry in variant.toml, and a [nasde.plugin]'s own skills/. Each SKILL.md must start with a --- YAML frontmatter line: Codex's loader rejects a file that opens with anything else (missing YAML frontmatter delimited by ---) and silently skips the skill. Put any provenance comment below the closing ---. See ADR-012.

If no harbor_config.json exists, nasde auto-generates one from variant.toml. To customize (e.g., add MCP servers), create it explicitly:

{
  "agents": [
    {
      "import_path": "nasde_toolkit.agents.configurable_claude:ConfigurableClaude",
      "name": "<variant-name>",
      "kwargs": {
        "sandbox_files": {
          "/app/CLAUDE.md": "/absolute/path/to/variants/<variant>/CLAUDE.md",
          "/logs/agent/sessions/.claude.json": "/absolute/path/to/variants/<variant>/claude_config.json"
        }
      }
    }
  ]
}

Critical: "name" field is REQUIRED — without it, Opik tagging breaks.

Variant design patterns

Design variants to test specific hypotheses:

• Minimal (baseline) — bare instructions, no extra guidance
• Guided — detailed domain-specific guidance, patterns to follow
• Skill-augmented — skills injected for domain expertise (e.g., tactical DDD)
• Tool-augmented — MCP server access (e.g., codebase search)
• Cross-agent — same instructions for Claude, Codex, and Gemini to compare agent performance

Every benchmark needs at least one variant (typically vanilla or baseline).

Step 6: Verify the benchmark works

Before running with a real agent:

1. Build the Docker image:

   docker build -t benchmark-test -f tasks/<task>/environment/Dockerfile .
   

2. Test the verifier with reference solution (if available):

   docker run --rm -it benchmark-test bash
   # Inside container:
   bash /path/to/solution/solve.sh
   bash /path/to/tests/test.sh
   cat /logs/verifier/reward.txt  # Should be 1
   

3. Dry run on a single task:

   nasde run --variant vanilla --tasks <task-name> --without-eval -C .
   

4. Final pre-flight on Windows authors — verify no CRLF leaked in:

   find tasks -name '*.sh' -exec sh -c 'file "$1" | grep -q CRLF && echo "BAD: $1"' _ {} \;
   find tasks -name 'Dockerfile' -exec sh -c 'file "$1" | grep -q CRLF && echo "BAD: $1"' _ {} \;
   # Both should print nothing.
   

   If anything prints, fix with sed -i 's/\r$//' <file> and re-commit.