Free TierAPI Key AuthOpenAPI Spec
Stigg is a billing and pricing infrastructure platform that enables companies to manage subscriptions, entitlements, and usage-based billing with built-in monetization controls.
#16 of 26 in Billing · #2 of 2 in Pricing · #2 of 4 in Subscriptions
Checklist Breakdown
13 of 33 checks passed.
14 unscored.
Can an agent find and understand this tool without a web search?
✓
Published OpenAPI/Swagger spec
✗
Has llms.txt or llms-full.txt
✗
Has an MCP server (official or well-maintained)
✗
MCP server listed in a public registry
✓
API reference docs are publicly accessible
✓
Docs include runnable code examples
✓
Has a public changelog or release notes
✓
Has a public status page
Can an agent create an account and get credentials without human intervention?
✗
Signup does not require CAPTCHA
✗
Signup does not require phone verification
✓
Supports API key auth (not only OAuth)
✗
API key obtainable without manual approval
✓
No mandatory billing info to start
✓
Can sign up without creating an organization
Can an agent operate autonomously without upfront payment or contracts?
✓
Has a free tier
✓
Usage-based pricing available
✓
No minimum contract or commitment
✓
Pricing page is public (no 'contact sales')
✓
Free tier sufficient for testing (not just a trial)
How well does the API work for non-human consumers?
—
SDK available in 2+ languages
—
Structured error responses (JSON with error codes)
—
Idempotency support on write endpoints
—
Pagination on list endpoints
—
Webhook/event support
—
Sandbox or test mode available
—
Rate limit headers in responses
—
Consistent REST resource naming
Does the tool fail gracefully when an agent makes a mistake?
—
Meaningful error messages (not just 500)
—
429 responses include Retry-After header
—
Documented uptime SLA (99.9%+)
—
Graceful degradation under rate limits
—
Request IDs in responses for debugging
—
API versioning supported
Reviewer Notes
Stigg has solid agent-friendly fundamentals: a public REST API with good documentation, API key authentication, and a sandbox environment for testing. The OpenAPI spec is available, which aids discovery. However, account creation requires manual sign-up (no programmatic account creation), and there's no MCP server or llms.txt file to accelerate agent discovery. The API is well-structured for billing operations, but agents would need human intervention to get started. The free tier and sandbox support autonomous operation once authenticated, making it moderately agent-native but with friction at the onboarding stage.
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