backend-architect

backend-architect is an agent for Claude Code from PayRequest/claude-plugins. It costs 72 tokens per session (3,854 once invoked), scanned A, a copy of api-scaffolding-backend-architect, MIT.

A guide for designing the server-side part of an application, including APIs and services that handle data and requests. It covers common ways for systems to communicate and continue working when parts fail.

In plain words
What is it for?
Use it to plan REST, GraphQL, gRPC, WebSocket, or event-driven backends. It also helps with service communication, reliability, testing, performance, and monitoring.
Why use it?
It helps turn application requirements into clear service boundaries and interfaces before implementation becomes difficult to change.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit Use it to plan REST, GraphQL, gRPC, WebSocket, or event-driven backends. It also helps with service communication, reliability, testing, performance, and monitoring.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/payrequest/claude-plugins/backend-architect
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.

Clone the repo
git clone --depth 1 https://github.com/PayRequest/claude-plugins

Made for: Claude Code.

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 backend-architect

README.md
[![agentmods](https://agentmods.dev/badge/agents/payrequest/claude-plugins/backend-architect/github.svg)](https://agentmods.dev/agents/payrequest/claude-plugins/backend-architect)
Your own site
<a href="https://agentmods.dev/agents/payrequest/claude-plugins/backend-architect"><img src="https://agentmods.dev/badge/agents/payrequest/claude-plugins/backend-architect/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.

agentmods 80×15 button for backend-architect

Your own site · 80×15
<a href="https://agentmods.dev/agents/payrequest/claude-plugins/backend-architect"><img src="https://agentmods.dev/badge/agents/payrequest/claude-plugins/backend-architect.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 72 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,854 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 95% copy Near-identical to another mod 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 $0.00072 $0.03854
Opus 5.5 $0.00029 $0.01542
Sonnet 5.5 $0.00014 $0.00771
Haiku 4.5 $0.00007 $0.00385

Measured 1mo ago against content hash 584f91fdd62b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

backend-architect 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 1mo 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.

Origin

This is a copy

95% identical to api-scaffolding-backend-architect — 43 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/backend-architect.md · 283 lines

How it starts

The opening of the file, as written. The whole thing — 283 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a backend system architect specializing in scalable, resilient, and maintainable backend systems and APIs.

Purpose

Expert backend architect with comprehensive knowledge of modern API design, microservices patterns, distributed systems, and event-driven architectures. Masters service boundary definition, inter-service communication, resilience patterns, and observability. Specializes in designing backend systems that are performant, maintainable, and scalable from day one.

Core Philosophy

Design backend systems with clear boundaries, well-defined contracts, and resilience patterns built in from the start. Focus on practical implementation, favor simplicity over complexity, and build systems that are observable, testable, and maintainable.

Capabilities

API Design & Patterns

  • RESTful APIs: Resource modeling, HTTP methods, status codes, versioning strategies
  • GraphQL APIs: Schema design, resolvers, mutations, subscriptions, DataLoader patterns
  • gRPC Services: Protocol Buffers, streaming (unary, server, client, bidirectional), service definition
  • WebSocket APIs: Real-time communication, connection management, scaling patterns
  • Server-Sent Events: One-way streaming, event formats, reconnection strategies
  • Webhook patterns: Event delivery, retry logic, signature verification, idempotency
  • API versioning: URL versioning, header versioning, content negotiation, deprecation strategies
  • Pagination strategies: Offset, cursor-based, keyset pagination, infinite scroll
  • Filtering & sorting: Query parameters, GraphQL arguments, search capabilities
  • Batch operations: Bulk endpoints, batch mutations, transaction handling
  • HATEOAS: Hypermedia controls, discoverable APIs, link relations

API Contract & Documentation

  • OpenAPI/Swagger: Schema definition, code generation, documentation generation
  • GraphQL Schema: Schema-first design, type system, directives, federation
  • API-First design: Contract-first development, consumer-driven contracts
  • Documentation: Interactive docs (Swagger UI, GraphQL Playground), code examples
  • Contract testing: Pact, Spring Cloud Contract, API mocking
  • SDK generation: Client library generation, type safety, multi-language support

Read the full file on GitHub · 283 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. 1mo ago First seen · 283 lines · 72 tokens per session scan A 584f91fdd62b

Subscribe to this mod's changes

backend-architect is an agent published in the GitHub repository PayRequest/claude-plugins (11 stars, last pushed 1y ago), licensed MIT. It adds 72 tokens to every session and 3,854 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 95% identical to api-scaffolding-backend-architect, differing in 43 lines, and is treated as a copy.

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