# Development Guide
**Complete guide for developing on the OpenAgents Control repository**
This guide covers everything you need to know to develop agents, commands, tools, and contribute to the OpenAgents Control ecosystem.
## Table of Contents
- [Getting Started](#getting-started)
- [Repository Structure](#repository-structure)
- [Development Workflow](#development-workflow)
- [Creating New Agents](#creating-new-agents)
- [Testing](#testing)
- [Best Practices](#best-practices)
- [Common Tasks](#common-tasks)
- [Troubleshooting](#troubleshooting)
---
## Getting Started
### Prerequisites
- **OpenCode CLI** installed ([installation guide](https://opencode.ai/docs))
- **Node.js** 18+ (for testing framework)
- **Git** for version control
- **Bash** (macOS/Linux) or **Git Bash** (Windows)
### Clone and Setup
```bash
# Clone the repository
git clone https://github.com/darrenhinde/OpenAgentsControl.git
cd OpenAgentsControl
# Install dependencies for testing framework
cd evals/framework
npm install
cd ../..
```
### Verify Setup
```bash
# Validate registry
make validate-registry
# Run tests
cd evals/framework
npm test
```
---
## Repository Structure
```
opencode-agents/
├── .opencode/ # OpenCode configuration
│ ├── agent/ # Agent prompts (category-based)
│ │ ├── core/
│ │ │ ├── openagent.md # Universal orchestrator
│ │ │ └── opencoder.md # Development specialist
│ │ ├── meta/
│ │ │ └── system-builder.md # System architect
│ │ ├── development/
│ │ │ ├── frontend-specialist.md
│ │ │ └── backend-specialist.md
│ │ ├── content/
│ │ │ └── copywriter.md
│ │ └── subagents/ # Specialized subagents
│ │ ├── code/ # Code-related subagents
│ │ ├── core/ # Core functionality subagents
│ │ ├── system-builder/ # System building subagents
│ │ └── utils/ # Utility subagents
│ ├── command/ # Slash commands
│ │ ├── openagents/ # OpenAgents Control-specific commands
│ │ │ └── new-agents/ # Agent creation system ⭐
│ │ └── prompt-engineering/ # Prompt optimization commands
│ ├── context/ # Context files
│ │ ├── core/ # Core context (standards, workflows)
│ │ ├── project/ # Project-specific context
│ │ └── system-builder-templates/ # Templates
│ ├── plugin/ # Plugins and integrations
│ ├── prompts/ # Prompt library (model variants, category-based)
│ │ ├── core/
│ │ │ ├── openagent/ # OpenAgent variants
│ │ │ └── opencoder/ # OpenCoder variants
│ │ └── development/
│ │ └── frontend-specialist/ # Frontend specialist variants
│ └── tool/ # Utility tools
├── evals/ # Testing framework
│ ├── agents/ # Agent test suites
│ │ ├── openagent/ # OpenAgent tests
│ │ └── opencoder/ # OpenCoder tests
│ ├── framework/ # Test framework code
│ │ ├── src/ # Framework source
│ │ └── scripts/ # Test utilities
│ └── results/ # Test results
├── scripts/ # Automation scripts
│ ├── registry/ # Registry management
│ ├── prompts/ # Prompt management
│ └── testing/ # Test utilities
├── docs/ # Documentation
│ ├── agents/ # Agent documentation
│ ├── contributing/ # Contribution guides
│ ├── features/ # Feature documentation
│ └── guides/ # User guides
└── registry.json # Component registry
```
### Key Directories Explained
#### `.opencode/agent/`
Main agent prompts organized by category. These are the "brains" of the system:
- **core/openagent.md** - Universal orchestrator with plan-first workflow
- **core/opencoder.md** - Development specialist for direct code execution
- **meta/system-builder.md** - System architecture generator
- **development/** - Development specialist agents (frontend, backend, devops)
- **content/** - Content creation agents (copywriter, technical-writer)
- **subagents/** - Specialized helpers for specific tasks
#### `.opencode/command/`
Slash commands that users can invoke:
- **openagents/new-agents/** - ⭐ **NEW**: Agent creation system with research-backed principles
- **prompt-engineering/** - Prompt optimization tools
#### `.opencode/context/`
Context files that agents load on-demand:
- **core/** - Standards, patterns, workflows
- **project/** - Project-specific context (CLAUDE.md pattern)
#### `.opencode/prompts/`
Prompt library with model-specific variants (category-based structure):
- Allows experimentation without breaking main branch
- Each variant has test results documented
- Organized by category matching agent structure (core/, development/, etc.)
#### `evals/`
Comprehensive testing framework:
- **agents/** - Test suites for each agent (8 essential tests)
- **framework/** - Testing infrastructure
- **results/** - Test results and reports
---
## Development Workflow
### 1. Create a Feature Branch
```bash
git checkout -b feature/my-new-feature
```
### 2. Make Your Changes
Follow the appropriate guide:
- [Creating New Agents](#creating-new-agents)
- [Adding Commands](#adding-commands)
- [Adding Tools](#adding-tools)
- [Writing Tests](#writing-tests)
### 3. Test Your Changes
```bash
# Validate structure
./scripts/registry/validate-component.sh
# Run tests
cd evals/framework
npm test -- --agent=your-agent
# Test manually
opencode --agent=your-agent
```
### 4. Commit and Push
```bash
git add .
git commit -m "feat: add new feature"
git push origin feature/my-new-feature
```
### 5. Create Pull Request
- Use conventional commit format in PR title
- Fill out PR template completely
- Ensure CI passes
---
## Creating New Agents
### ⭐ NEW: Research-Backed Agent Creation System
We now have a streamlined system for creating agents following **Anthropic 2025 research best practices**.
#### Quick Start
```bash
# Use the agent creation command
/create-agent my-agent-name
# Or invoke directly
opencode "Create a new agent called 'python-dev' for Python development"
```
#### What Gets Created
The system generates:
1. **Minimal agent prompt** (~500 tokens at "right altitude")
2. **Project context file** (CLAUDE.md pattern)
3. **8 comprehensive tests** (planning, context, incremental, tools, errors, thinking, compaction, completion)
4. **Test configuration**
5. **Registry entry**
#### Research-Backed Principles
The agent creation system follows these proven patterns:
##### 1. Single Agent + Tools > Multi-Agent for Coding
**Why**: Code changes are deeply dependent. Sub-agents can't coordinate edits to the same file.
**Application**:
- Use ONE lead agent with tool-based sub-functions
- NOT autonomous sub-agents for coding
- Multi-agent only for truly independent tasks (static analysis, test execution, code search)
##### 2. Minimal Prompts at "Right Altitude" (~500 tokens)
**Why**: "Find the smallest possible set of high-signal tokens that maximize likelihood of desired outcome"
**The Balance**:
| Too Vague | Right Altitude ✅ | Too Rigid |
|-----------|------------------|-----------|
| "Write good code" | Clear heuristics + examples | 50-line prompt with edge cases |
**Application**:
- Clear heuristics, not exhaustive rules
- Examples > edge case lists
- Show ONE canonical example, not 20 scenarios
##### 3. Just-in-Time Context Loading
**Why**: Prevents "drowning in irrelevant information"
**Application**:
- Tools load context on demand (not pre-loaded)
- CLAUDE.md pattern for project context
- File metadata guides behavior
##### 4. Tool Clarity
**Why**: "Tool ambiguity is one of the biggest failure modes"
**Application**:
```markdown
Load specific file for analysis or modification
You need to examine or edit a file
You already have the file content in context
```
##### 5. Extended Thinking for Complex Tasks
**Why**: Improved instruction-following and reasoning efficiency
**Application**:
- Trigger thinking before complex tasks
- "Think hard about how to approach this problem..."
- Phrases mapped to thinking budget (think, think hard, think harder)
##### 6. Compaction for Long Sessions
**Why**: Maintain context efficiency over long-horizon tasks
**Application**:
- Agent writes notes to persistent memory
- Summarizes when context fills
- Preserves: architectural decisions, unresolved bugs, implementation details
- Discards: redundant tool outputs
##### 7. Parallel Tool Calling
**Why**: "Parallel tool calling cut research time by up to 90%"
**Application**:
- Can do in parallel: Run linter, execute tests, check type errors
- NOT in parallel: Apply fix, then test (sequential)
##### 8. Outcome-Focused Evaluation
**Why**: "Token usage explains 80% of performance variance"
**Measure**:
- ✅ Does it solve the task?
- ✅ Token usage reasonable?
- ✅ Tool calls appropriate?
- ❌ NOT: "Did it follow exact steps I imagined?"
#### Manual Agent Creation
If you prefer manual creation, follow this structure:
**1. Create Agent File** (`.opencode/agent/my-agent.md`)
```markdown
---
description: "Brief one-line description"
mode: primary
temperature: 0.1
tools:
read: true
write: true
edit: true
bash: true
glob: true
grep: true
permissions:
bash:
"rm -rf *": "ask"
"sudo *": "deny"
edit:
"**/*.env*": "deny"
"**/*.key": "deny"
---
# My Agent
Clear, concise role - what this agent does
1. Read and understand the context
2. Think about the approach before acting
3. Implement changes incrementally
4. Verify each step with appropriate tools
5. Complete with clear summary
- Decompose problems before implementing
- Use tools intentionally (not speculatively)
- Verify outputs before claiming completion
- Stop on errors and report (don't auto-fix blindly)
**User**: "typical request"
**Agent**:
1. Read relevant files
2. Think about approach
3. Implement change
4. Verify
**Result**: Expected outcome
```
**2. Create Context File** (`.opencode/context/project/my-agent-context.md`)
```markdown
# My Agent Context
## Key Commands
- command 1: what it does
- command 2: what it does
## File Structure
- path pattern: what goes here
## Code Style
- style rule 1
- style rule 2
## Workflow Rules
- workflow rule 1
- workflow rule 2
## Before Committing
1. check 1
2. check 2
```
**3. Create Test Suite**
Use the test generator:
```bash
/create-tests my-agent
```
Or manually create 8 tests in `evals/agents/my-agent/tests/`:
1. `planning/planning-approval-001.yaml`
2. `context-loading/context-before-code-001.yaml`
3. `implementation/incremental-001.yaml`
4. `implementation/tool-usage-001.yaml`
5. `error-handling/stop-on-failure-001.yaml`
6. `implementation/extended-thinking-001.yaml`
7. `long-horizon/compaction-001.yaml`
8. `completion/handoff-001.yaml`
**4. Register Agent**
The registry auto-updates on merge to main, or manually:
```bash
./scripts/registry/register-component.sh
```
#### Templates
Pre-built templates are available in:
```
.opencode/command/openagents/new-agents/templates/
├── agent-template.md # Minimal agent template
├── context-template.md # CLAUDE.md pattern
├── test-config-template.yaml # Test configuration
└── test-*.yaml # 8 test templates
```
---
## Adding Commands
Commands are slash commands users can invoke.
### Structure
```markdown
---
description: "What this command does"
---
# Command Name
$ARGUMENTS
What this command specializes in
Specific objective of this command
Action and process
Action and process
```
### Example
See `.opencode/command/openagents/new-agents/create-agent.md` for a complete example.
---
## Adding Tools
Tools are TypeScript utilities that agents can use.
### Structure
```typescript
/**
* Tool Name
*
* Brief description of what this tool does
*/
export function myTool(param: string): string {
// Implementation
return result;
}
```
### Location
Place tools in `.opencode/tool/my-tool/index.ts`
---
## Testing
### Test Framework
We use a comprehensive evaluation framework in `evals/framework/`.
### Running Tests
```bash
# Run all tests
cd evals/framework
npm test
# Run tests for specific agent
npm test -- --agent=openagent
# Run specific category
npm test -- --agent=openagent --category=planning
# Run single test
npm test -- --agent=openagent --test=planning-approval-001
# Verbose output
npm test -- --verbose
```
### Writing Tests
Each agent should have 8 essential test types:
1. **Planning & Approval** - Verify plan-first approach
2. **Context Loading** - Ensure just-in-time context retrieval
3. **Incremental Implementation** - Verify step-by-step execution
4. **Tool Usage** - Check correct tool selection
5. **Error Handling** - Verify stop-on-failure behavior
6. **Extended Thinking** - Check decomposition before coding
7. **Compaction** - Verify long session handling
8. **Completion** - Check proper output and handoff
### Test Structure
```yaml
id: test-id-001
name: Test Name
description: |
What this test verifies
category: planning
agent: my-agent
model: anthropic/claude-sonnet-4-5
prompt: |
Test prompt
behavior:
mustContain:
- "expected text"
mustNotContain:
- "forbidden text"
mustUseAnyOf: [[tool1], [tool2]]
minToolCalls: 1
expectedViolations:
- rule: rule-name
shouldViolate: false
severity: error
approvalStrategy:
type: auto-approve
timeout: 30000
tags:
- tag1
- tag2
```
### Test Templates
Use the templates in `.opencode/command/openagents/new-agents/templates/` as starting points.
---
## Best Practices
### Agent Design
✅ **Do**:
- Keep system prompts minimal (~500 tokens)
- Use clear heuristics, not exhaustive rules
- Provide ONE canonical example
- Define tools with clear purpose and when to use/not use
- Load context on-demand (just-in-time)
- Measure outcomes: Does it solve the task?
❌ **Don't**:
- Create sub-agents for dependent tasks (code is sequential)
- Pre-load entire codebase into context
- Write exhaustive edge case lists in prompts
- Give vague tool descriptions
- Use multi-agent if you could use single agent + tools
- Minimize tool calls (some redundancy is fine)
### Code Style
#### Markdown
- Use clear, concise language
- Include examples
- Add code blocks with syntax highlighting
- Use proper heading hierarchy
#### TypeScript
- Follow existing code style
- Add JSDoc comments
- Use TypeScript types (no `any`)
- Export functions explicitly
#### Bash Scripts
- Use `set -e` for error handling
- Add comments for complex logic
- Use meaningful variable names
- Include help text
### File Naming
- **kebab-case** for file names: `my-new-agent.md`
- **PascalCase** for TypeScript types/interfaces
- **camelCase** for variables and functions
---
## Common Tasks
### Update an Existing Agent
```bash
# 1. Edit the agent file
vim .opencode/agent/my-agent.md
# 2. Test changes
cd evals/framework
npm test -- --agent=my-agent
# 3. Update tests if needed
vim evals/agents/my-agent/tests/...
# 4. Commit
git add .
git commit -m "feat: improve my-agent behavior"
```
### Add a New Test
```bash
# 1. Create test file
vim evals/agents/my-agent/tests/new-category/new-test-001.yaml
# 2. Update config
vim evals/agents/my-agent/config/config.yaml
# Add new category to testPaths
# 3. Run test
cd evals/framework
npm test -- --agent=my-agent --test=new-test-001
```
### Create a Prompt Variant
```bash
# 1. Copy template
cp .opencode/prompts/core/openagent/TEMPLATE.md .opencode/prompts/core/openagent/my-variant.md
# 2. Edit variant
vim .opencode/prompts/core/openagent/my-variant.md
# 3. Test variant
./scripts/prompts/test-prompt.sh core/openagent my-variant
# 4. Update README with results
vim .opencode/prompts/core/openagent/README.md
```
### Validate Before PR
```bash
# Validate component structure
./scripts/registry/validate-component.sh
# Ensure using default prompts
./scripts/prompts/validate-pr.sh
# Run all tests
cd evals/framework
npm test
# Validate registry
make validate-registry
```
---
## Troubleshooting
### Tests Failing
**Problem**: Tests fail after making changes
**Solution**:
1. Check test output for specific failures
2. Run with `--verbose` flag for details
3. Verify agent follows expected behavior
4. Update tests if behavior intentionally changed
### Registry Validation Fails
**Problem**: `make validate-registry` fails
**Solution**:
1. Check `registry.json` syntax
2. Ensure all referenced files exist
3. Verify frontmatter in agent files is valid YAML
4. Run `./scripts/registry/validate-component.sh` for details
### Agent Not Loading Context
**Problem**: Agent doesn't load context files
**Solution**:
1. Verify context file exists in `.opencode/context/`
2. Check agent has `read` tool enabled
3. Ensure context file path is correct
4. Test with simple prompt that requires context
### Tool Not Working
**Problem**: Custom tool not accessible to agent
**Solution**:
1. Verify tool is in `.opencode/tool/my-tool/index.ts`
2. Check tool is exported properly
3. Ensure agent has tool enabled in frontmatter
4. Rebuild if needed: `cd .opencode/tool && npm run build`
---
## Additional Resources
### Documentation
- [Contributing Guide](CONTRIBUTING.md) - General contribution guidelines
- [Agent Creation System](../../.opencode/command/openagents/new-agents/README.md) - Detailed agent creation guide
- [Research-Backed Prompt Design](../agents/research-backed-prompt-design.md) - Prompt engineering principles
- [Test Design Guide](../../evals/framework/docs/test-design-guide.md) - Writing effective tests
### Examples
- [OpenAgent](../../.opencode/agent/core/openagent.md) - Universal orchestrator example
- [OpenCoder](../../.opencode/agent/core/opencoder.md) - Development specialist example
- [Subagents](../../.opencode/agent/subagents/) - Specialized subagent examples
- [Test Suites](../../evals/agents/) - Comprehensive test examples
### Tools
- [Agent Creation Command](../../.opencode/command/openagents/new-agents/create-agent.md)
- [Test Generator Command](../../.opencode/command/openagents/new-agents/create-tests.md)
- [Prompt Optimizer](../../.opencode/command/prompt-engineering/prompt-enhancer.md)
---
## Questions?
- **Issues**: Open an issue for bugs or feature requests
- **Discussions**: Use GitHub Discussions for questions
- **Security**: Email security issues privately
---
**Happy developing! 🚀**