cross-repo-contract

cross-repo-contract is a skill for Claude Code, Codex from groupzer0/vs-code-agents. It costs 0 tokens per session (568 once invoked), scanned A, original, MIT.

A set of rules for working with APIs shared across multiple repositories, where a repository is a project’s source-code storage location. It uses local contract files to define the expected requests, responses, errors, and endpoints.

In plain words
What is it for?
Use it before building or consuming cross-repository API endpoints, to find contract definitions, reference request and response types, and propose a standard contract directory when one is missing.
Why use it?
It reduces mismatches between services and clients when an API changes. Reading the shared contract first helps implementations use the same types and behavior.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/groupzer0/vs-code-agents/cross-repo-contract
Any agent
npx skills add groupzer0/vs-code-agents --skill cross-repo-contract
Clone the repo
git clone --depth 1 https://github.com/groupzer0/vs-code-agents

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cross-repo-contract

README.md
[![agentmods](https://agentmods.dev/badge/skills/groupzer0/vs-code-agents/cross-repo-contract.svg)](https://agentmods.dev/skills/groupzer0/vs-code-agents/cross-repo-contract)
Your own site
<a href="https://agentmods.dev/skills/groupzer0/vs-code-agents/cross-repo-contract"><img src="https://agentmods.dev/badge/skills/groupzer0/vs-code-agents/cross-repo-contract.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 568 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00568
Opus 5 $0.00000 $0.00284
Sonnet 5 $0.00000 $0.00114
Haiku 4.5 $0.00000 $0.00057

Measured 6d ago against content hash aa3d81551f95, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

cross-repo-contract scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

vs-code-agents/skills/cross-repo-contract/SKILL.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cross-Repository API Contract Skill

Purpose

When implementing or consuming APIs that span multiple repositories, ensure type safety and contract adherence by working with locally available contract definitions.

Contract Discovery

Before implementing any API endpoint or client, check for contract definitions in these locations (in order of precedence):

  1. api-contract/ — This repo is the source of truth for the contract
  2. .contracts/ — Synced copy from an external source repo (typically via CI)

If neither exists and you are implementing API endpoints, propose creating an api-contract/ directory following the standard structure.

Standard Contract Structure

api-contract/ (or .contracts/)
├── README.md       # Purpose, sync instructions, change process
├── version.ts      # Contract version and changelog
├── types.ts        # TypeScript interfaces for all request/response/error shapes
└── endpoints.md    # Human-readable endpoint documentation

Implementation Guidelines

When Implementing API Endpoints (Backend)

  1. Read .contracts/types.ts (or api-contract/types.ts) before writing handler code
  2. Import or reference the types directly — do not redefine them
  3. Validate that Lambda/function request and response shapes match the contract exactly
  4. If the contract is missing fields you need, document as an OPEN QUESTION — do not add fields unilaterally

When Implementing API Clients (Extension/Frontend)

  1. Read api-contract/types.ts before writing client code
  2. Import types directly from the contract location
  3. Handle all error codes defined in the contract
  4. If the API behaves differently than the contract specifies, flag this as a bug

When Proposing Contract Changes

  1. Additive changes (new optional fields, new endpoints): Safe to propose inline
  2. Breaking changes (removing fields, changing types): Document as OPEN QUESTION with migration notes
  3. Always bump the version in version.ts when modifying types.ts
  4. Note that breaking changes require coordinated releases across repos

Read the full file on GitHub · 65 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 65 lines · 0 tokens per session scan A aa3d81551f95

Subscribe to this mod's changes

cross-repo-contract is a skill published in the GitHub repository groupzer0/vs-code-agents (284 stars, last pushed 7mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 568 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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