api-contract-tester

Validate CYPHER V3 API routes for schema compliance and latency.

4|1|Updated Feb 12, 2026
One-click install
npx skills add https://github.com/0xjc65eth/CYPHER-V3 --skill api-contract-tester
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: api-contract-tester
Source: https://github.com/0xjc65eth/CYPHER-V3/tree/main/skills/api-contract-tester
Command: npx skills add https://github.com/0xjc65eth/CYPHER-V3 --skill api-contract-tester

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Prevents silent contract breakages between CYPHER V3 backend routes and the frontend by validating that endpoints return the expected keys, shapes, and live values so bugs do not reach users unnoticed.

Core Features & Use Cases

  • Schema contract assertions: checks required fields and types for BTC market, ordinals, runes, BRC-20, and fee endpoints.
  • Real-data validation: detects mocked or hardcoded responses by asserting reasonable value ranges and content patterns.
  • Performance monitoring: measures latency and flags slow or timing-out endpoints.
  • Breaking-change detection: saves JSON snapshots and compares top-level keys to detect schema drift before deployments.
  • Use Case: integrate into local testing or CI to fail pull requests that remove fields, introduce mock data, or degrade endpoint performance.

Quick Start

Run the API contract tester against a running CYPHER V3 instance at http://localhost:4444 to validate endpoints, schemas, and latency.

Frequently Asked Questions about api-contract-tester

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I prevent silent API breaking changes in CI?

You can prevent silent API breaking changes in CI by running schema validation tests against live endpoints, checking JSON response keys, and comparing snapshots to fail pull requests that introduce schema drift or mock data. This ensures endpoints return expected shapes and live values before deployment.

How does API contract testing detect mocked or hardcoded responses?

API contract testing detects mocked or hardcoded responses through real-data validation, which asserts that endpoint values fall within reasonable ranges and match expected content patterns, flagging any static or fake data that deviates from live API behavior.

Can I validate BRC-20 and ordinals endpoint schemas against a local server?

Yes, you can validate BRC-20, ordinals, and BTC market endpoint schemas against a local server by providing an accessible CYPHER V3 server URL to check required fields, types, and response latency for schema integrity.

What is the best way to monitor API endpoint performance and latency thresholds?

The best way to monitor API endpoint performance is by applying contract tests that measure response latency and flag slow or timing-out endpoints, ensuring your market data, fee, and token routes meet defined latency thresholds during local and CI runs.

Do I need a running server to test API contracts and schema compliance?

Yes, you need an accessible CYPHER V3 server URL to test API contracts and schema compliance, because the validation process checks live endpoints for required JSON response keys, real-data values, and latency metrics.

Why does schema validation fail when top-level JSON keys are removed?

Schema validation fails when top-level JSON keys are removed because the contract tester saves JSON snapshots and compares them to detect breaking changes, intentionally failing CI runs if expected fields are missing to prevent frontend integration bugs.