Sendy Agent Native Score | Agent Native Registry

Checklist Breakdown

9 of 33 checks passed. 14 unscored.

Discovery 50%

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

Auth & Onboarding 33%

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

Pricing 60%

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)

Agent Tooling Not yet scored

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

Reliability Not yet scored

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

Sendy lacks modern agent discovery mechanisms—no MCP server, OpenAPI spec, or llms.txt file. Documentation exists but requires manual navigation. The API accepts form-encoded POST requests returning JSON, which is serviceable but not agent-optimized. Self-hosted deployment means agents cannot programmatically create accounts; users must purchase a license and install the application themselves. Reliability depends on user infrastructure and Amazon SES configuration rather than Sendy's control. One-time purchase model is favorable for autonomous agents avoiding recurring charges, but setup friction significantly limits agent accessibility.

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