Postscript

https://postscript.io
39
Fair
Agent Native Score
Free TierAPI Key AuthOpenAPI Spec

Postscript is an SMS and email marketing platform designed for e-commerce businesses to drive customer engagement and retention through personalized messaging campaigns.

Categories: Communications · E Commerce
#34 of 63 in Communications · #9 of 42 in E Commerce
Checklist Breakdown

13 of 33 checks passed. 14 unscored.

Discovery 63%

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 50%

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 100%

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

Postscript has an API with documented endpoints and OAuth support, but lacks MCP server or llms.txt for easy agent discovery. Account creation requires manual setup through the web interface with email verification, preventing programmatic signup. The API documentation exists but is not comprehensive; structured responses are available but error handling could be more granular. Rate limiting is in place with reasonable free tier access, though sandbox environment is unavailable for testing.

Top 10 Lists
Top 10 Communications → Top 10 E Commerce →

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