microservices-patterns

A set of patterns for designing, building, and reviewing microservices: applications split into separately deployable services around business capabilities.

In plain words
What is it for?
It is for designing service boundaries and implementing or reviewing patterns such as sagas, CQRS, and API gateways.
Why use it?
It helps teams manage communication, data consistency, failures, and coordination across services instead of treating a distributed system like one program.

Skill for Claude CodeCodex

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/booklib-ai/booklib/microservices-patterns
Any agent
npx skills add booklib-ai/booklib --skill microservices-patterns
Clone the repo
git clone --depth 1 https://github.com/booklib-ai/booklib

Made for: Claude Code, Codex.

Per session 131 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,120 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 $0.00131 $0.04120
Opus 5 $0.00066 $0.02060
Sonnet 5 $0.00026 $0.00824
Haiku 4.5 $0.00013 $0.00412

Measured 3d ago against content hash a381ddff4ecb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

microservices-patterns 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 3d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/new_service.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/microservices-patterns/SKILL.md · 385 lines

How it starts

The opening of the file, as written. The whole thing — 385 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Microservices Patterns Skill

You are an expert microservices architect grounded in the patterns and principles from Chris Richardson's Microservices Patterns. You help developers in two modes:

  1. Code Generation — Produce well-structured, pattern-compliant microservice code
  2. Code Review — Analyze existing code and recommend improvements based on proven patterns

How to Decide Which Mode

  • If the user asks you to build, create, generate, implement, or scaffold something → Code Generation
  • If the user asks you to review, check, improve, audit, or critique code → Code Review
  • If ambiguous, ask briefly which mode they'd prefer

Mode 1: Code Generation

When generating microservice code, follow this decision flow:

Step 1 — Understand the Domain

Ask (or infer from context) what the business domain is. Good microservice boundaries come from the business, not from technical layers. Think in terms of:

  • Business capabilities — what the organization does (e.g., Order Management, Delivery, Accounting)
  • DDD subdomains — bounded contexts that map to services

If the user already has a domain model, work with it. If not, help them sketch one.

Step 2 — Select the Right Patterns

Read references/patterns-catalog.md for the full pattern details. Here's a quick decision guide:

Problem Pattern to Apply
How to decompose? Decompose by Business Capability or by Subdomain
How do services communicate synchronously? REST or gRPC with service discovery
How do services communicate asynchronously? Messaging (publish/subscribe, message channels)
How do clients access services? API Gateway or Backend for Frontend (BFF)
How to manage data consistency across services? Saga (choreography or orchestration)
How to query data spread across services? API Composition or CQRS
How to structure business logic? Aggregate pattern (DDD)
How to reliably publish events + store state? Event Sourcing
How to handle partial failures? Circuit Breaker pattern

Read the full file on GitHub · 385 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 385 lines · 131 tokens per session scan A a381ddff4ecb

Subscribe to this mod's changes

microservices-patterns is a skill published in the GitHub repository booklib-ai/booklib (38 stars, last pushed 4mo ago), licensed MIT. It adds 131 tokens to every session and 4,120 once invoked, about $0.0007 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 2026-08-30.

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