Agents
Agents are the core workers in Tessera. Each agent is a specialized AI with specific capabilities and expertise.
Defining Agents
Agents are defined in ~/.config/tessera/config.yaml:
agents:
definitions:
- name: "python-expert"
model: "gpt-4o"
provider: "openai"
capabilities: ["python", "coding", "testing"]
phase_affinity: ["implementation", "execution"]
system_prompt_file: "~/.config/tessera/prompts/python-expert.md"
temperature: 0.5
Agent Properties
Required Fields
- name - Unique identifier for the agent
- model - LLM model to use (gpt-4, claude-3-5-sonnet, etc.)
- provider - LLM provider (openai, vertex_ai, anthropic, etc.)
Optional Fields
- capabilities - List of skills (used for task routing)
- phase_affinity - Which workflow phases this agent excels at
- system_prompt_file - Path to markdown file with agent instructions
- system_prompt - Inline prompt (alternative to file)
- temperature - LLM temperature (0.0-2.0)
- context_size - Max tokens
- timeout - Request timeout in seconds
- max_retries - Retry count for failed requests
System Prompts
Define agent behavior with markdown prompts:
# ~/.config/tessera/prompts/python-expert.md
You are a Python expert specializing in clean, well-tested code.
## Responsibilities
- Write Pythonic, PEP 8 compliant code
- Add comprehensive docstrings
- Include type hints
- Handle edge cases and errors
## Code Style
- Prefer list comprehensions over loops
- Use pathlib over os.path
- Add logging for debugging
## Testing
- Write pytest tests for all functions
- Aim for >90% coverage
- Test edge cases and error conditions
Agent Capabilities
Capabilities help Tessera route tasks to the right agents:
Common capabilities:
- python, javascript, rust - Programming languages
- testing, pytest, unittest - Testing frameworks
- documentation, writing - Documentation
- security, code-review - Quality assurance
- devops, docker, kubernetes - Operations
Phase Affinity
Agents can specify which workflow phases they're best suited for:
user_interview- Requirements gatheringresearch- Information collectionarchitecture- System designimplementation- Codingtesting- Quality assurancereview- Code reviewdocumentation- Docs writing
Examples
Specialist Agent
- name: "security-expert"
model: "gpt-4"
provider: "openai"
capabilities: ["security", "code-review", "penetration-testing"]
phase_affinity: ["review"]
system_prompt: |
You are a security expert. Review code for vulnerabilities.
Check for: SQL injection, XSS, CSRF, auth issues.
temperature: 0.2 # Low temperature for consistency
Generalist Agent
- name: "full-stack-dev"
model: "gpt-4o"
provider: "openai"
capabilities: ["python", "javascript", "sql", "docker"]
phase_affinity: ["implementation", "testing", "documentation"]
system_prompt_file: "~/.config/tessera/prompts/full-stack.md"
Best Practices
- Specific system prompts - Clear instructions yield better results
- Lower temperature for deterministic tasks - Code review, testing
- Higher temperature for creative tasks - Architecture, design
- Appropriate models - Use cheaper models (gpt-4o-mini) for simple tasks
- Clear capabilities - Helps supervisor route tasks correctly