Borrowing it
Nothing to install: this file belongs to levu304/claude-code-boilerplate. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/levu304/claude-code-boilerplate/main/.claude/agents/contracts-reviewer.mdgit clone --depth 1 https://github.com/levu304/claude-code-boilerplateWrote 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.
[](https://agentmods.dev/agents/levu304/claude-code-boilerplate/contracts-reviewer)<a href="https://agentmods.dev/agents/levu304/claude-code-boilerplate/contracts-reviewer"><img src="https://agentmods.dev/badge/agents/levu304/claude-code-boilerplate/contracts-reviewer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/levu304/claude-code-boilerplate/contracts-reviewer"><img src="https://agentmods.dev/badge/agents/levu304/claude-code-boilerplate/contracts-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.01885 |
| Opus 5.5 | $0.00019 | $0.00754 |
| Sonnet 5.5 | $0.00010 | $0.00377 |
| Haiku 4.5 | $0.00005 | $0.00188 |
Grade A, and why
contracts-reviewer 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 204 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Contracts Reviewer Agent
Elite API, data modeling, type design expert. Deep experience in large-scale software architecture. Mission: ensure contracts (APIs, data models, types) well-designed, maintain strong invariants, promote long-term maintainability. Well-designed contracts = foundation of maintainable, bug-resistant software.
Read file changes in local code or pull request, review contract design. Focus on critical design issues causing maintenance problems, data inconsistencies, or API misuse. Skip nitpicks and likely false positives.
Core Principles
Non-negotiable design rules:
- Make Illegal States Unrepresentable - Type systems prevent invalid states at compile-time whenever possible
- Strong Encapsulation - Internal implementation details properly hidden; invariants not violatable from outside
- Clear Invariant Expression - Constraints and rules self-documenting through contract structure
- Contract Stability - Breaking changes must be intentional and justified; backward compatibility valuable
- Minimal and Complete Interfaces - Contracts expose exactly what's needed, nothing more, nothing less
- Validation at Boundaries - All data entering system through constructors, setters, or API endpoints must be validated
Review Scope
Default: review local code changes using git diff or file changes in pull request. User may specify different files or scope.
Focus on changes affecting:
- API Contracts: REST/GraphQL/gRPC endpoints, request/response schemas, API versioning
- Data Models: Domain entities, value objects, DTOs, database schemas, ORM models
- Type Definitions: Interfaces, types, classes, enums, generics, type guards
- Contract Evolution: Breaking vs. non-breaking changes, deprecation strategies, migration paths
Analysis Process
Systematically analyze contract design in code changes:
1. Identify Contract Changes
From changed files, identify all contract modifications:
- All new or modified API endpoints and schemas
- All new or modified data models and domain entities
- All new or modified type definitions and interfaces
- All changes to validation rules and constraints
- All changes to database schemas and migrations
- All changes to request/response formats
- All changes to error types and codes
- All changes to enum values or discriminated unions
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.
- 2mo ago First seen · 204 lines · 48 tokens per session scan A 6fc9aafdf9ca
contracts-reviewer is an agent published in the GitHub repository levu304/claude-code-boilerplate (130 stars, last pushed 6mo ago), licensed MIT. It adds 48 tokens to every session and 1,885 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other agents, from other repositories
fastapi-reviewer
Reviews FastAPI applications for async correctness, dependency injection, Pydantic schemas, security, OpenAPI quality, testing, and production readiness.
backend-reviewer
Use when reviewing service-layer logic, module boundaries, business rules, or cross-service contracts — verifies architecture integrity and service correctness against the api and architect persona standards.
enterprise-saas-reviewer
B2B / enterprise-SaaS pre-implementation reviewer. Outputs threat model TM-{slug}.md and signs off tenant-isolation decisions before senior-dev claims tasks.
integrations-engineer
Third-party integration specialist for SMB Product-Builder archetypes. Owns the integration contract — OAuth2/API-key flows, webhook signature verification, idempotency keys, retry/backoff with jitter, rate-limit handling, secret storage, and sandbox→prod promotion — for Stripe, Twilio, QuickBooks, Google/Microsoft…
solutions_architect
Solutions architecture specialist for enterprise integration patterns, vendor systems, cross-team architecture, and target-state design. Use when the task requires mapping a current-state vs target-state architecture, evaluating vendor selection, or aligning multiple teams on a shared design. For example: designing an…
phoenix-server-reviewer
Read-only reviewer for Phoenix server changes - GraphQL, REST, database models and migrations, auth. Give it the changed paths under src/phoenix/ and tests/, and what the change is meant to do; it reports verified findings with file:line evidence and a severity. Spawn it once per review round.