perstack.toml Reference

• Complete Example
• Runtime Configuration
• Expert Definition
• Skill Definition

Complete Example

# Runtime configuration
model = "claude-sonnet-4-5"
reasoningBudget = "medium"
maxSteps = 50
maxRetries = 3
timeout = 60000
envPath = [".env", ".env.local"]

[provider]
providerName = "anthropic"
[provider.setting]
headers = { "X-Custom-Header" = "value" }

# Expert definition
[experts."my-expert"]
version = "1.0.0"
description = "TypeScript and React code reviewer with security analysis"
instruction = """
You are a code reviewer specializing in TypeScript and React.
Review code for type safety, performance, accessibility, and security.
Provide constructive feedback with specific examples.
"""
delegates = ["@org/security-expert", "performance-analyzer"]

# Base skill (optional)
[experts."my-expert".skills."@perstack/base"]
type = "mcpStdioSkill"
description = "Base filesystem and shell tools"
command = "npx"
packageName = "@perstack/base"

# MCP Stdio skill
[experts."my-expert".skills."web-search"]
type = "mcpStdioSkill"
description = "Search the web for documentation and best practices"
rule = "Use for finding up-to-date documentation and security advisories"
command = "npx"
packageName = "exa-mcp-server"
pick = ["web_search_exa"]
requiredEnv = ["EXA_API_KEY"]

# MCP SSE skill
[experts."my-expert".skills."static-analyzer"]
type = "mcpSseSkill"
description = "Remote static analysis service"
endpoint = "https://api.example.com/static-analysis"
pick = ["analyze_typescript"]
omit = ["analyze_python"]

# Interactive skill
[experts."my-expert".skills."user-interaction"]
type = "interactiveSkill"
description = "Interactive tools for user feedback"
rule = "Use when clarification is needed from the user"

[experts."my-expert".skills."user-interaction".tools."askUser"]
description = "Ask user for input or clarification"
inputJsonSchema = """
{
  "type": "object",
  "properties": {
    "question": {
      "type": "string",
      "description": "Question to ask the user"
    }
  },
  "required": ["question"]
}
"""

Runtime Configuration

Top-level settings that apply to all Experts in the file.

model = "claude-sonnet-4-5"
reasoningBudget = "medium"
maxSteps = 100
maxRetries = 10
timeout = 60000

[provider]
providerName = "anthropic"
[provider.setting]
baseUrl = "https://custom-endpoint.example.com"
headers = { "X-Custom-Header" = "value" }

Field	Type	Description
model	string	Model name
reasoningBudget	string or number	Native LLM reasoning budget (minimal, low, medium, high, or token count)
maxSteps	number	Maximum steps per run
maxRetries	number	Maximum retry attempts
timeout	number	Timeout per generation (ms)
envPath	string[]	Paths to environment files

Provider Configuration

Configure LLM provider under [provider] table.

[provider]
providerName = "anthropic"  # Required: anthropic, google, openai, deepseek, ollama, azure-openai, amazon-bedrock, google-vertex
[provider.setting]
# Provider-specific options (all optional)

Field	Type	Description
providerName	string	LLM provider name (required)
setting	object	Provider-specific settings (optional)

Provider Settings by Provider

Anthropic (providerName = "anthropic")

Setting	Type	Description
baseUrl	string	Custom API endpoint
headers	object	Custom HTTP headers

Google (providerName = "google")

Setting	Type	Description
baseUrl	string	Custom API endpoint
headers	object	Custom HTTP headers

OpenAI (providerName = "openai")

Setting	Type	Description
baseUrl	string	Custom API endpoint
organization	string	OpenAI organization ID
project	string	OpenAI project ID
name	string	Custom provider name
headers	object	Custom HTTP headers

Ollama (providerName = "ollama")

Setting	Type	Description
baseUrl	string	Ollama server URL
headers	object	Custom HTTP headers

Azure OpenAI (providerName = "azure-openai")

Setting	Type	Description
resourceName	string	Azure resource name
apiVersion	string	Azure API version
baseUrl	string	Custom API endpoint
headers	object	Custom HTTP headers
useDeploymentBasedUrls	boolean	Use deployment-based URLs

Amazon Bedrock (providerName = "amazon-bedrock")

Setting	Type	Description
region	string	AWS region

Google Vertex AI (providerName = "google-vertex")

Setting	Type	Description
project	string	GCP project ID
location	string	GCP location (e.g., us-central1)
baseUrl	string	Custom API endpoint
headers	object	Custom HTTP headers

DeepSeek (providerName = "deepseek")

Setting	Type	Description
baseUrl	string	Custom API endpoint
headers	object	Custom HTTP headers

See Providers and Models for available models and environment variables.

Expert Definition

Define Experts under [experts."expert-key"].

[experts."my-expert"]
version = "1.0.0"
description = "Brief description of the expert"
instruction = """
Detailed instructions for the expert's behavior.
Can be multi-line.
"""
delegates = ["other-expert", "@org/another-expert"]

Field	Type	Required	Description
version	string	No	Semantic version (default: 1.0.0)
minRuntimeVersion	string	No	Minimum runtime version
description	string	No	Brief description (max 2048 chars)
instruction	string	Yes	Behavior instructions (max 20KB)
delegates	string[]	No	Experts this Expert can delegate to
tags	string[]	No	Tags for categorization
providerTools	string[]	No	Provider-specific tool names (e.g., ["webSearch", "codeExecution"])
providerSkills	array	No	Anthropic Agent Skills (builtin or custom)
providerToolOptions	object	No	Provider tool options (e.g., webSearch maxUses, allowedDomains)

Skill Definition

Define skills under [experts."expert-name".skills."skill-name"].

MCP Stdio Skill

[experts."my-expert".skills."my-skill"]
type = "mcpStdioSkill"
description = "Skill description"
rule = "Additional usage guidelines"
command = "npx"
packageName = "mcp-server-package"
args = ["-y", "additional-args"]
pick = ["tool1", "tool2"]
omit = ["tool3"]
requiredEnv = ["API_KEY"]

Field	Type	Required	Description
type	literal	Yes	"mcpStdioSkill"
description	string	No	Skill description
rule	string	No	Additional usage guidelines
command	string	Yes	Command to execute (npx, python, uvx)
packageName	string	No	Package name (for npx)
args	string[]	No	Command-line arguments
pick	string[]	No	Tools to include (whitelist)
omit	string[]	No	Tools to exclude (blacklist)
requiredEnv	string[]	No	Required environment variables
allowedDomains	string[]	No	Allowed domain patterns for network access
lazyInit	boolean	No	Delay initialization until first use (default: false)

MCP SSE Skill

[experts."my-expert".skills."remote-skill"]
type = "mcpSseSkill"
description = "Remote MCP server"
endpoint = "https://api.example.com/mcp"
pick = ["tool1"]
omit = ["tool2"]

Field	Type	Required	Description
type	literal	Yes	"mcpSseSkill"
description	string	No	Skill description
rule	string	No	Additional usage guidelines
endpoint	string	Yes	MCP server URL
pick	string[]	No	Tools to include
omit	string[]	No	Tools to exclude
allowedDomains	string[]	No	Allowed domain patterns for network access

Interactive Skill

[experts."my-expert".skills."user-interaction"]
type = "interactiveSkill"
description = "User interaction skill"

[experts."my-expert".skills."user-interaction".tools."askUser"]
description = "Ask user for input"
inputJsonSchema = """
{
  "type": "object",
  "properties": {
    "question": { "type": "string" }
  },
  "required": ["question"]
}
"""

Field	Type	Required	Description
type	literal	Yes	"interactiveSkill"
description	string	No	Skill description
rule	string	No	Additional usage guidelines
tools	object	Yes	Tool definitions

Tool definition:

Field	Type	Required	Description
description	string	No	Tool description
inputJsonSchema	string	Yes	JSON Schema for input