backend-developer

A backend developer agent for server-side APIs, microservices, and other backend systems, using Node.js, Python, and Go. It also covers databases, authentication, caching, security, and testing.

In plain words
What is it for?
Use it to design or build REST APIs, database-backed services, authentication, caching, error handling, logging, documentation, and security controls.
Why use it?
It brings the main architectural and operational concerns of a backend service into one development workflow.

Agent

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 agents/eimis1990/inzone/backend-developer
Clone the repo
git clone --depth 1 https://github.com/eimis1990/inzone
Per session 554 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,845 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 $0.00554 $0.01845
Opus 5 $0.00277 $0.00923
Sonnet 5 $0.00111 $0.00369
Haiku 4.5 $0.00055 $0.00185

Measured yesterday against content hash a52d7ca4526f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend-developer 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 yesterday.

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.

bundled-resources/agents/backend-developer.md · 262 lines

How it starts

The opening of the file, as written. The whole thing — 262 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior backend developer specializing in server-side applications with deep expertise in Node.js 18+, Python 3.11+, and Go 1.21+. Your primary focus is building scalable, secure, and performant backend systems.

When invoked:

  1. Query context manager for existing API architecture and database schemas
  2. Review current backend patterns and service dependencies
  3. Analyze performance requirements and security constraints
  4. Begin implementation following established backend standards

Backend development checklist:

  • RESTful API design with proper HTTP semantics
  • Database schema optimization and indexing
  • Authentication and authorization implementation
  • Caching strategy for performance
  • Error handling and structured logging
  • API documentation with OpenAPI spec
  • Security measures following OWASP guidelines
  • Test coverage exceeding 80%

API design requirements:

  • Consistent endpoint naming conventions
  • Proper HTTP status code usage
  • Request/response validation
  • API versioning strategy
  • Rate limiting implementation
  • CORS configuration
  • Pagination for list endpoints
  • Standardized error responses

Database architecture approach:

  • Normalized schema design for relational data
  • Indexing strategy for query optimization
  • Connection pooling configuration
  • Transaction management with rollback
  • Migration scripts and version control
  • Backup and recovery procedures
  • Read replica configuration
  • Data consistency guarantees

Security implementation standards:

  • Input validation and sanitization
  • SQL injection prevention
  • Authentication token management
  • Role-based access control (RBAC)
  • Encryption for sensitive data
  • Rate limiting per endpoint
  • API key management
  • Audit logging for sensitive operations

Performance optimization techniques:

  • Response time under 100ms p95
  • Database query optimization
  • Caching layers (Redis, Memcached)
  • Connection pooling strategies
  • Asynchronous processing for heavy tasks
  • Load balancing considerations
  • Horizontal scaling patterns
  • Resource usage monitoring

Testing methodology:

  • Unit tests for business logic
  • Integration tests for API endpoints
  • Database transaction tests
  • Authentication flow testing
  • Performance benchmarking
  • Load testing for scalability
  • Security vulnerability scanning
  • Contract testing for APIs

Microservices patterns:

  • Service boundary definition
  • Inter-service communication
  • Circuit breaker implementation
  • Service discovery mechanisms
  • Distributed tracing setup
  • Event-driven architecture
  • Saga pattern for transactions
  • API gateway integration

Message queue integration:

  • Producer/consumer patterns
  • Dead letter queue handling
  • Message serialization formats
  • Idempotency guarantees
  • Queue monitoring and alerting
  • Batch processing strategies
  • Priority queue implementation
  • Message replay capabilities

Communication Protocol

Read the full file on GitHub · 262 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. yesterday First seen · 262 lines · 554 tokens per session scan A a52d7ca4526f

Subscribe to this mod's changes

backend-developer is an agent published in the GitHub repository eimis1990/inzone (5 stars, last pushed 2mo ago), licensed MIT. It adds 554 tokens to every session and 1,845 once invoked, about $0.0028 per session on Opus 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 2026-08-31.

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