advanced-patterns

advanced-patterns is a skill for Claude Code from oborchers/fractional-cto. It costs 81 tokens per session (2,881 once invoked), scanned A, original, MIT.

Guidance for API designs that need patterns beyond basic create, read, update, and delete operations. It covers bulk requests, real-time connections, separate customer or tenant data, gateways, CQRS, and event sourcing.

In plain words
What is it for?
Designing batch operations, real-time APIs using server-sent events or WebSockets, multi-tenant systems, API gateways, CQRS, or event-sourced systems.
Why use it?
It helps choose a suitable design when ordinary REST endpoints create friction. REST is a common way for software to exchange data over HTTP.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the api-design-principles plugin — 13 skills, 1 command, 1 agent shipped together

Good fit Designing batch operations, real-time APIs using server-sent events or WebSockets, multi-tenant systems, API gateways, CQRS, or event-sourced systems.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/oborchers/fractional-cto/advanced-patterns
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.

Any agent
npx skills add oborchers/fractional-cto --skill advanced-patterns
Clone the repo
git clone --depth 1 https://github.com/oborchers/fractional-cto

Made for: Claude Code.

Or install api-design-principles, the plugin that ships this one along with the rest of its 13 skills, 1 command, 1 agent.

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 advanced-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/oborchers/fractional-cto/advanced-patterns/github.svg)](https://agentmods.dev/skills/oborchers/fractional-cto/advanced-patterns)
Your own site
<a href="https://agentmods.dev/skills/oborchers/fractional-cto/advanced-patterns"><img src="https://agentmods.dev/badge/skills/oborchers/fractional-cto/advanced-patterns/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 advanced-patterns

Your own site · 80×15
<a href="https://agentmods.dev/skills/oborchers/fractional-cto/advanced-patterns"><img src="https://agentmods.dev/badge/skills/oborchers/fractional-cto/advanced-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,881 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 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 5.1 $0.00081 $0.02881
Opus 5 $0.00041 $0.01440
Sonnet 5 $0.00016 $0.00576
Haiku 4.5 $0.00008 $0.00288

Measured 9d ago against content hash 330c006215fc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

advanced-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 9d 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.

api-design-principles/skills/advanced-patterns/SKILL.md · 191 lines

How it starts

The opening of the file, as written. The whole thing — 191 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Know When to Break the REST Rules

Standard REST with JSON covers most API needs. But some problems -- bulk data import, real-time streaming, multi-tenant isolation, high read:write asymmetry -- demand patterns that go beyond basic CRUD. Reach for these when standard REST creates friction, not before.

Bulk and Batch Operations

When clients need to create, update, or delete many resources at once, individual requests are wasteful. Batch endpoints eliminate the round-trip overhead.

Use the simple batch pattern for homogeneous operations:

Send an array of resources to a dedicated /batch endpoint. Cap batch size at 100 items per request to keep response times predictable and memory usage bounded. Return per-item status with an index for correlation -- never silently drop failures.

Design for partial success, not all-or-nothing:

Approach When to Use HTTP Status
Atomic (all-or-nothing) Financial transactions, consistency-critical operations 200 or 400/422 (all rolled back)
Partial success Import operations, bulk updates with independent items 200 with per-item status
Async processing Large batches (1,000+ items) 202 Accepted, poll for results

Every batch response must include a summary object with total, succeeded, and failed counts. For failed items, return the original index and a structured error so the caller knows exactly what to retry.

Switch to async for large batches:

Return 202 Accepted with a Location header pointing to a status resource. The client polls that resource for progress updates. Include estimated_completion when possible. Provide a separate errors endpoint for downloading failures as JSON or CSV. This is the pattern Shopify uses for bulk mutations and Stripe uses for bulk payouts.

REST vs GraphQL vs gRPC vs tRPC

Pick the protocol that matches the consumer, not the one that sounds most modern.

Aspect REST GraphQL gRPC tRPC
Latency Good Good Excellent (binary, HTTP/2) Good
Caching Excellent (HTTP-native) Hard (POST, single endpoint) Custom solution required Custom solution required
Tooling Mature, abundant Strong (Apollo, Relay) Strong (protoc, buf) TypeScript-native
Learning curve Low Medium Medium-High Low (TypeScript only)
Browser support Native Native (fetch/POST) Requires grpc-web proxy Native
Type safety Via codegen from OpenAPI Via codegen from SDL Native (protobuf) Native (TS inference)
Best for Public APIs, broad ecosystem Flexible frontend data needs Service-to-service Full-stack TS monorepos

Read the full file on GitHub · 191 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. 9d ago First seen · 191 lines · 81 tokens per session scan A 330c006215fc

Subscribe to this mod's changes

advanced-patterns is a skill published in the GitHub repository oborchers/fractional-cto (29 stars, last pushed 1mo ago), licensed MIT. It adds 81 tokens to every session and 2,881 once invoked, about $0.0004 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.

Related

Other skills, from other repositories

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

agui-dotnet-protobuf

Use the protobuf wire transport (instead of the default Server-Sent Events) for an AG-UI connection with the AG-UI .NET SDK — a compact binary event stream negotiated via the Accept header. USE FOR: making an AGUIChatClient prefer protobuf by wiring an AGUIEventStreamHandler with ProtobufEventStreamFormatter (then…

ag-ui-protocol/ag-ui · 162 tokens

azure-mgmt-botservice-dotnet

Azure Resource Manager SDK for Bot Service in .NET. Management plane operations for creating and managing Azure Bot resources, channels (Teams, DirectLine, Slack), and connection settings. Triggers: "Bot Service", "BotResource", "Azure Bot", "DirectLine channel", "Teams channel", "bot management .NET", "create bot".

microsoft/skills · 78 tokens

fastapi-router-py

Create FastAPI routers with CRUD operations, authentication dependencies, and proper response models. Use when building REST API endpoints, creating new routes, implementing CRUD operations, or adding authenticated endpoints in FastAPI applications.

microsoft/skills · 46 tokens

migrate-segw-to-rap

Reverse-engineer a SEGW-built OData V2 service (MPC/DPC/MPCEXT/DPCEXT) into a modern RAP V4 service — tables, CDS views (interface + projection), behavior definitions, draft entities, service definition + binding. Use when asked to "migrate this SEGW service to RAP", "convert OData V2 to V4 RAP", "modernize this…

arc-mcp/arc-1 · 106 tokens

telnyx-messaging-hosted-curl

Set up hosted SMS numbers, toll-free verification, and RCS messaging. Use when migrating numbers or enabling rich messaging features. This skill provides REST API (curl) examples.

team-telnyx/ai · 45 tokens