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API · 4 min read ·

Safe demo APIs with validation and rate limits

  • validation
  • rate-limit
  • demo API

Problem

Portfolios claim API skill without showing a request/response path — or they proxy expensive APIs with no limits.

Approach

Expose POST /api/demo that validates JSON, sanitizes input, rate-limits by IP, and returns a mock result with zero paid upstream calls.

Result

Interactive playground at /lab/playground.

What I learned

Demo endpoints should prove engineering habits (validation, limits), not burn API budget.

Related insights

Keep exploring

Ask the grounded assistant about this decision, or open the lab playground.