system-interface-contracts

Name: system-interface-contracts
Availability: InStock
Author: jacob-balslev

Define stable interface contracts with fields, invariants, and versioning rules.

1|Updated May 6, 2026

Search Tags:#versioning #error handling #observability #idempotency #interface contracts #system boundaries #contract tests

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npx skills add https://github.com/jacob-balslev/skill-graph --skill system-interface-contracts

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: system-interface-contracts
Source: https://github.com/jacob-balslev/skill-graph/tree/main/marketplace/skills/system-interface-contracts
Command: npx skills add https://github.com/jacob-balslev/skill-graph --skill system-interface-contracts

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

It prevents integration drift by making system-to-system boundaries explicit, testable, and resilient to change.

Core Features & Use Cases

Contract-first boundary definition: Specify producer/consumer ownership, inputs/outputs, invariants, and forbidden states so modules can evolve without breaking each other.
Deterministic behavior requirements: Define error, retry, timeout, idempotency/deduplication rules, and observability needed to prove the contract is honored.
Compatibility and versioning guidance: Separate additive vs breaking changes and set deprecation/versioning expectations for safe evolution.
Verification checklist + eval surface: Provide a structured authoring gate and an evaluation artifact to support consistent review.

Quick Start

Use system-interface-contracts to write a clear contract before multiple modules or agents implement different sides of the same boundary, including fields, invariants, error/timeout/retry, idempotency, and versioning rules.

Frequently Asked Questions about system-interface-contracts

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

FAQPage Schema

What is an interface contract and how does it prevent integration drift?▼

An interface contract makes system-to-system boundaries explicit by defining producer and consumer ownership, inputs, outputs, and invariants, which prevents modules from breaking each other during evolution.

How do I define idempotency and retry rules for API boundaries?▼

You define deterministic behavior rules for API boundaries by specifying explicit error handling, timeout, retry, and idempotency or deduplication expectations within the interface contract to ensure producers and consumers remain aligned.

How do I version API changes without breaking existing consumers?▼

Version API changes safely by separating additive modifications from breaking changes within the interface contract, setting clear deprecation expectations and compatibility rules so existing consumers can adapt without failures.

What should be included in contract tests for system boundaries?▼

Contract tests for system boundaries should include verification criteria and fixtures covering both positive and negative cases, ensuring that required fields, forbidden states, and observability expectations are consistently honored.

When do I need to write an interface contract for my services?▼

You need to write an interface contract before multiple modules, services, or agents implement different sides of the same boundary, ensuring that ownership, invariants, and deterministic behavior are explicitly agreed upon.

Does defining system boundaries require specifying forbidden states?▼

Yes, defining system boundaries requires specifying forbidden states alongside required and optional fields to establish clear invariants, ensuring that modules can evolve safely without violating expected interface behavior.