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.
npx agentmods add skills/kid-sid/codex-spellbook/microservicesnpx skills add kid-sid/codex-spellbook --skill microservicesgit clone --depth 1 https://github.com/kid-sid/codex-spellbookWhat 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 | $0.00041 | $0.03201 |
| Opus 5 | $0.00020 | $0.01600 |
| Sonnet 5 | $0.00008 | $0.00640 |
| Haiku 4.5 | $0.00004 | $0.00320 |
Grade A, and why
microservices 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 2d 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 — 387 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Microservices Patterns
Design and implementation patterns for decomposing monoliths and building reliable distributed backend systems.
When to Activate
- Decomposing a monolith into services or defining service boundaries
- Choosing between synchronous (REST/gRPC) and asynchronous (messaging) communication
- Implementing resilience patterns: circuit breaker, retry, bulkhead, timeout
- Designing data ownership and cross-service transactions (Saga, CQRS)
- Setting up an API gateway or BFF for client-facing traffic
- Designing for eventual consistency or event-driven workflows
- Debugging distributed failures, cascading errors, or data inconsistency
Service Decomposition
Decomposition Strategies
| Strategy | Approach | Best For |
|---|---|---|
| By domain (DDD) | Align services to bounded contexts | Greenfield, domain-rich systems |
| By subdomain | Core / supporting / generic subdomains | Prioritising build-vs-buy |
| Strangler fig | Incrementally replace monolith routes | Existing monoliths |
| By volatility | Isolate frequently-changing logic | High-churn business rules |
Bounded Context Rules
# BAD: Shared User model across services
OrderService → reads User.loyaltyPoints
PaymentService → reads User.billingAddress
EmailService → reads User.email
# GOOD: Each service owns what it needs
OrderService → owns OrderCustomer { id, name, loyaltyPoints }
PaymentService → owns PaymentProfile { userId, billingAddress, paymentMethods }
EmailService → owns ContactRecord { userId, email, preferences }
Each service owns its data. No direct cross-service DB queries.
Strangler Fig Migration
1. Route all traffic through a facade (nginx / API gateway)
2. Identify one vertical slice (e.g., /api/payments/*)
3. Implement that slice as a new service
4. Re-route the facade to the new service
5. Delete the monolith code for that slice
6. Repeat — monolith shrinks, services grow
Inter-Service Communication
Sync vs Async Decision
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.
- 2d ago First seen · 387 lines · 41 tokens per session scan A 95de2b13aa2f
microservices is a skill published in the GitHub repository kid-sid/codex-spellbook (21 stars, last pushed 3mo ago), licensed MIT. It adds 41 tokens to every session and 3,201 once invoked, about $0.0002 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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