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.