Declarative Configuration

Understanding secretspec.toml and its declarative approach

SecretSpec uses secretspec.toml to declare what secrets your application needs, separating requirements from storage mechanisms for portability across environments.

Basic Structure

[project]
name = "my-app"
revision = "1.0"
extends = ["../shared/common"]  # Optional: inherit from other configs


[profiles.default]
DATABASE_URL = { description = "PostgreSQL connection string", required = true }
API_KEY = { description = "External API key", required = true }
SESSION_SECRET = { description = "Session signing secret", required = true, type = "password", generate = true }

Secret Declarations

Each secret is declared with configuration options:

SECRET_NAME = {
  description = "Human-readable explanation",  # Required: shown in prompts
  required = true,                            # Optional: defaults to true
  default = "value"                           # Optional: fallback if not set
}

Options:

• description: Explains the secret’s purpose (required in the default profile; profile overrides inherit it when omitted)
• required: Whether the secret must be provided (default: true)
• default: Fallback value for optional secrets
• composed (0.16+): Derive a read-only value from other declared secrets (see Composed Secrets for the strict template and dependency semantics)
• type: Secret type for auto-generation (password, hex, base64, uuid, command, rsa_private_key, openpgp_private_key (0.21+), and ssh_private_key (0.21+))
• generate: Enable auto-generation when the secret is missing (true or a table with options)
• prompt (0.19+): Securely ask for a missing value during secretspec run and let the selected provider decide whether to save the answer

Related Concepts

• Configuration Inheritance lets projects share common secret definitions via the extends field
• Secret Generation auto-creates passwords, tokens, and keys when secrets are missing
• Run prompts (0.19+) provision stored secrets on first use, or remain invocation-only with null
• Composed Secrets (0.16+) derive values from other declared secrets without dotenv or shell expansion

Best Practices

1. Descriptive names: Use STRIPE_API_KEY instead of generic API_KEY
2. Clear descriptions: Help developers understand each secret’s purpose
3. Sensible defaults: Provide development defaults, require production values
4. Modular inheritance: Create reusable base configurations for common patterns

Complete Example

[project]
name = "web-api"
revision = "1.0"
extends = ["../shared/base", "../shared/auth"]


[profiles.default]
# Inherits DATABASE_URL, INTERNAL_API_KEY from base
# Inherits JWT_SECRET, SESSION_SECRET from auth
# Service-specific additions:
STRIPE_API_KEY = { description = "Stripe payment API", required = true }
REDIS_URL = { description = "Redis cache connection", required = true }
PORT = { description = "Server port", required = false, default = "3000" }

Last updated Oct 11, 2026