massgen-config-creator

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Guide for creating properly structured YAML configuration files for MassGen. This skill should be used when agents need to create new configs for examples, case studies, testing, or demonstrating features.

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Config Creator

This skill provides guidance for creating new YAML configuration files that follow MassGen conventions and best practices.

Purpose

The config-creator skill helps you create well-structured, validated configuration files for MassGen agents. It ensures consistency across the codebase and helps avoid common mistakes.

When to Use This Skill

Use the config-creator skill when you need to:

Create example configs demonstrating new features
Write configs for case studies or releases
Build reusable multi-agent workflow configs
Test new backend or tool integrations
Share configuration patterns with users

Authoritative Documentation

IMPORTANT: The primary source of truth for config creation is:

📖 docs/source/development/writing_configs.rst

This file contains:

Complete config creation workflow
All current conventions and rules
Property placement reference
Validation checklist
Common patterns and examples
Up-to-date templates

Always consult this document for the latest configuration standards.

Critical Rules (Quick Reference)

1. Never Invent Properties

ALWAYS read 2-3 existing configs first to understand current conventions:

# Find similar configs
ls massgen/configs/tools/{category}/

# Read examples
cat massgen/configs/basic/multi/two_agents_gemini.yaml
cat massgen/configs/tools/mcp/filesystem_claude.yaml

2. Property Placement Matters

cwd → BACKEND-level (individual agent workspace)
context_paths → ORCHESTRATOR-level (shared read-only files)
enable_web_search → BACKEND-level
enable_planning_mode → ORCHESTRATOR.COORDINATION-level

See docs/source/development/writing_configs.rst for complete property reference.

3. Key Conventions

✅ DO:

Prefer cost-effective models (gpt-5-nano, gpt-5-mini, gemini-2.5-flash)
Give all agents identical system_message
Use separate workspaces per agent
Include "What happens" comments explaining execution flow

❌ DON'T:

Reference massgen v1 or legacy paths
Invent new properties
Suggest cleanup commands that delete logs

Quick Start Workflow

Step 1: Research Existing Configs

# Find configs in your category
ls massgen/configs/tools/{relevant_category}/

# Read 2-3 similar examples
cat massgen/configs/basic/multi/two_agents_gemini.yaml

Step 2: Copy and Adapt

Copy a similar config as your starting point
Adapt values, never invent properties
Follow the structure from existing configs

Step 3: Test

massgen --config massgen/configs/tools/{category}/{your_config}.yaml "Test prompt"

Step 4: Validate

Refer to the validation checklist in docs/source/development/writing_configs.rst

File Naming and Location

Naming Pattern:

{agent_description}_{feature}.yaml

Location Categories:

massgen/configs/basic/ - Simple examples
massgen/configs/tools/filesystem/ - Filesystem operations
massgen/configs/tools/web-search/ - Web search
massgen/configs/tools/code-execution/ - Code execution
massgen/configs/tools/multimodal/ - Image, vision, audio
massgen/configs/tools/mcp/ - MCP integrations
massgen/configs/tools/planning/ - Planning mode

Common Patterns (Quick Reference)

Single Agent

agent:  # Singular
  id: "my_agent"
  backend:
    type: "claude"
    model: "claude-sonnet-4"

Multi-Agent

agents:  # Plural
  - id: "agent_a"
    backend:
      type: "openai"
      model: "gpt-5-mini"
    system_message: "Shared task description"

  - id: "agent_b"
    backend:
      type: "gemini"
      model: "gemini-2.5-flash"
    system_message: "Shared task description"

With Filesystem Access

agents:
  - backend:
      cwd: "workspace1"  # Backend-level

orchestrator:
  context_paths:  # Orchestrator-level
    - path: "massgen/configs/resources/v0.0.29-example/source"
      permission: "read"

Reference Files

Primary Documentation:

Config writing guide: docs/source/development/writing_configs.rst ⭐ START HERE
YAML schema reference: docs/source/reference/yaml_schema.rst
Example configs: massgen/configs/

Supporting Documentation:

Supported models: docs/source/reference/supported_models.rst
Backend configuration: docs/source/user_guide/backends.rst
MCP integration: docs/source/user_guide/mcp_integration.rst

Tips for Agents

When creating configs programmatically:

Always read the authoritative docs first: docs/source/development/writing_configs.rst
Read existing configs to understand current patterns
Copy structure from similar configs, don't invent
Test immediately after creating
When in doubt, consult the full guide in docs/source/development/writing_configs.rst

This skill is a quick reference guide. For comprehensive, up-to-date information, always refer to the official documentation files listed above.