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.
git clone --depth 1 https://github.com/EngineerWithAI/engineerwith-agentsWrote 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/engineerwithai/engineerwith-agents/backend-architect)<a href="https://agentmods.dev/agents/engineerwithai/engineerwith-agents/backend-architect"><img src="https://agentmods.dev/badge/agents/engineerwithai/engineerwith-agents/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.
<a href="https://agentmods.dev/agents/engineerwithai/engineerwith-agents/backend-architect"><img src="https://agentmods.dev/badge/agents/engineerwithai/engineerwith-agents/backend-architect.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 | $0.00072 | $0.03854 |
| Opus 5.5 | $0.00029 | $0.01542 |
| Sonnet 5.5 | $0.00014 | $0.00771 |
| Haiku 4.5 | $0.00007 | $0.00385 |
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.
This is a copy
97% identical to api-scaffolding-backend-architect — 41 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.
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
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.
- 1mo ago First seen · 283 lines · 72 tokens per session scan A e1376b3aee9d
backend-architect is an agent published in the GitHub repository EngineerWithAI/engineerwith-agents (4 stars, last pushed 9mo 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 97% identical to api-scaffolding-backend-architect, differing in 41 lines, and is treated as a copy.
Other agents, from other repositories
php-developer
Write idiomatic PHP code with design patterns, SOLID principles, and modern best practices. Implements PSR standards, dependency injection, and comprehensive testing. Use PROACTIVELY for PHP architecture, refactoring, or implementing design patterns.
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.
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…
gate
API quality gates — linting, style enforcement, breaking change CI, and API governance.
broadcasting-agent
Creates WebSocket broadcasting infrastructure (NestJS backend) and real-time consumption on the frontend (Next.js or React). Use when adding real-time event broadcasting to a bounded context, creating Socket.IO gateways, or implementing frontend event listeners. Dispatched after infrastructure layer is complete.
dotnet-architecture-reviewer
Reviews a .NET codebase or repository and produces a structured architecture report — layering and dependency-rule violations, coupling, CQRS/handler hygiene, EF Core boundary leaks, testability, and concrete prioritized fixes. Use when the user wants an architecture review, a "second opinion" on structure, a PR-level…