pypict Test Case Generator (Claude Skill) — Install & Live Demo

Why use it

Key features

Pairwise/N-wise test generation
Constraint syntax (IF/THEN parameter rules)
Translates plain-English parameter descriptions into pict models
Outputs test cases as a table or as test code skeletons
Works with pytest, JUnit, etc.

Live Demo

What it looks like in practice

pypict-claude-skill.replay ▶ ready

0/0

Install

Pick your client

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "pypict-claude-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/omkamal/pypict-claude-skill",
        "~/.claude/skills/pypict-claude-skill"
      ],
      "_inferred": true
    }
  }
}

Open Claude Desktop → Settings → Developer → Edit Config. Restart after saving.

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "pypict-claude-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/omkamal/pypict-claude-skill",
        "~/.claude/skills/pypict-claude-skill"
      ],
      "_inferred": true
    }
  }
}

Cursor uses the same mcpServers schema as Claude Desktop. Project config wins over global.

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "pypict-claude-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/omkamal/pypict-claude-skill",
        "~/.claude/skills/pypict-claude-skill"
      ],
      "_inferred": true
    }
  }
}

Click the MCP Servers icon in the Cline sidebar, then "Edit Configuration".

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "pypict-claude-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/omkamal/pypict-claude-skill",
        "~/.claude/skills/pypict-claude-skill"
      ],
      "_inferred": true
    }
  }
}

Same shape as Claude Desktop. Restart Windsurf to pick up changes.

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "pypict-claude-skill",
      "command": "git",
      "args": [
        "clone",
        "https://github.com/omkamal/pypict-claude-skill",
        "~/.claude/skills/pypict-claude-skill"
      ]
    }
  ]
}

Continue uses an array of server objects rather than a map.

~/.config/zed/settings.json

{
  "context_servers": {
    "pypict-claude-skill": {
      "command": {
        "path": "git",
        "args": [
          "clone",
          "https://github.com/omkamal/pypict-claude-skill",
          "~/.claude/skills/pypict-claude-skill"
        ]
      }
    }
  }
}

Add to context_servers. Zed hot-reloads on save.

claude mcp add pypict-claude-skill -- git clone https://github.com/omkamal/pypict-claude-skill ~/.claude/skills/pypict-claude-skill

One-liner. Verify with claude mcp list. Remove with claude mcp remove.

Use Cases

Real-world ways to use pypict Test Case Generator

Cover a feature with combinatorial inputs without writing 64 tests

👤 QA + devs writing integration tests ⏱ ~15 min intermediate

When to use: Feature has 4+ enum-ish parameters and exhaustive testing would explode.

Prerequisites

Server/skill installed and authenticated — See repo README

Flow

Model

Use pypict skill: model checkout with payment_method=[card, paypal, applepay], shipping=[standard, express, intl], discount=[none, code, member], currency=[USD, EUR].✓ Copied

→ Pict model + ~12 pairwise cases
Generate tests

Emit pytest tests from those cases against checkout().✓ Copied

→ pytest file with parametrize

Outcome: Real combinatorial coverage with ~12 cases instead of 81.

Pitfalls

Pairwise misses higher-order bugs (3-way interactions). For safety-critical paths, use 3-wise. — Pairwise misses higher-order bugs (3-way interactions). For safety-critical paths, use 3-wise.

Cost & Limits

What this costs to run

API quota: See provider docs for rate limits
Tokens per call: Varies by tool
Monetary: See repo README for pricing details
Tip: Cache tool results and avoid repeated identical calls.

Security

Permissions, secrets, blast radius

Credential storage: Use environment variables; never commit secrets

Data egress: Tool calls go to the provider's API as documented

Troubleshooting

Common errors and fixes

pict binary not found

Install Microsoft's pict tool (or pypict bundles it). See pypict README.

Verify: pypict.exec_pict('test')

constraints rejected

pict constraint syntax is strict: IF [A] = "x" THEN [B] <> "y";. Use the skill's validator.

Verify: Run validator first

Alternatives

pypict Test Case Generator vs others

Alternative	When to use it instead	Tradeoff
Plain parametrize	Few parameters	No combinatorial benefit

More

Resources

📖 Read the official README on GitHub

🐙 Browse open issues

🔍 Browse all 400+ MCP servers and Skills