Borrowing it
Nothing to install: this file belongs to vinkius-labs/mcpfusion. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/vinkius-labs/mcpfusion/main/.claude/skills/mcpfusion-development/SKILL.mdgit clone --depth 1 https://github.com/vinkius-labs/mcpfusionWrote 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/skills/vinkius-labs/mcpfusion/mcpfusion-development)<a href="https://agentmods.dev/skills/vinkius-labs/mcpfusion/mcpfusion-development"><img src="https://agentmods.dev/badge/skills/vinkius-labs/mcpfusion/mcpfusion-development/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/skills/vinkius-labs/mcpfusion/mcpfusion-development"><img src="https://agentmods.dev/badge/skills/vinkius-labs/mcpfusion/mcpfusion-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00119 | $0.04373 |
| Opus 5 | $0.00060 | $0.02187 |
| Sonnet 5 | $0.00024 | $0.00875 |
| Haiku 4.5 | $0.00012 | $0.00437 |
Grade A, and why
mcpfusion-development 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- mcpfusion-development — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 488 lines — stays where its author put it; the contents beside it link to each section on GitHub.
mcpfusion development Guide
MCP Fusion is a TypeScript framework for MCP servers built on the MVA (Model-View-Agent) pattern. The Model validates data, the Presenter (View) shapes what the AI perceives, and Tools (Agent layer) wire it all together.
For the complete API reference with all type signatures, read llms.txt at the root of the repository. This skill covers the essential patterns and rules.
Reference Examples
Complete, runnable examples are available in references/. Read them for concrete implementation patterns:
| Example | Domain | Patterns Shown |
|---|---|---|
| example-complete-crud.ts | Product Catalog | Full MVA lifecycle: Model → Presenter → Router → Query/Mutation/Action, ErrorBuilder, State Sync |
| example-proxy-api.ts | Blog Platform | .proxy() API pass-through, .fromModel(), field aliases, path params (:id), .handle() vs .proxy() decision tree |
| example-server-setup.ts | Generic App | Full server bootstrap: context, initMCPFusion(), middleware, autoDiscover(), prompts, State Sync policies, startServer() |
| example-testing.ts | Customer Service | @mcpfusion/testing: Egress Firewall assertions, JIT System Rules, RBAC middleware, error handling, Symbol Invisibility |
Project Structure
src/
├── models/ ← M — defineModel() declarations
│ ├── InvoiceModel.ts
│ └── UserModel.ts
├── views/ ← V — Presenters
│ ├── invoice.presenter.ts
│ └── user.presenter.ts
├── agents/ ← A — Tool definitions
│ ├── billing.tool.ts
│ └── users.tool.ts
├── index.ts ← ToolRegistry + registerAll()
└── server.ts ← attachToServer() bootstrap
Layer import rule: agents/ → views/ → models/ → @mcpfusion/core. Never import backwards.
The Golden Rules
- ALWAYS use
defineModel()for domain entity schemas — never rawz.object(). Models go inmodels/. - Presenters receive Models via
.schema(MyModel)— the Presenter is the egress firewall. with*()methods are for tool INPUT parameters only (filters, IDs, pagination) — NOT for domain schemas.- Handlers return raw data — the framework wraps with
success()automatically. No boilerplate. - One Model + one Presenter per entity, reused across every tool and prompt.
- Use semantic verbs:
f.query()= readOnly,f.mutation()= destructive,f.action()= neutral.
What ships with it
4 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.
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.
- 9d ago First seen · 488 lines · 119 tokens per session scan A 699746ef0438
mcpfusion-development is a skill published in the GitHub repository vinkius-labs/mcpfusion (256 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 119 tokens to every session and 4,373 once invoked, about $0.0006 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.
Other skills, from other repositories
api-security
Use for authorized security assessment of REST, GraphQL, WebSocket, or SOAP APIs, including discovery, authentication, authorization, rate-limit, and CI/CD testing.
protocol-reverse
Use for authorized reverse engineering of custom binary protocols, Protobuf/gRPC, WebSocket frames, and PCAP-driven protocol recovery.
building-mcp-servers
Use this skill whenever the user wants to design, build, harden, review, or debug an MCP (Model Context Protocol) server — including "build me an MCP server for X", connecting an AI agent/Claude to a database or API, adding tools/resources to an existing MCP server, reviewing a contributor PR against an MCP server, or…
implementing-mcp-resources
Implement new MCP resources and resource templates in the deno-mcp-template project. Provides the exact file structure, type signatures, registration steps, and patterns for static resources, KV-backed resources, resource templates with URI patterns, and subscription-based updates. Use when adding a new resource…
webhooks
Webhook subscriptions for the Ayrshare MCP server: register, unregister, and list HTTPS push notifications so an agent or app is notified on events instead of polling. Use whenever someone wants event push: "notify me when a post publishes", "let me know when a scheduled post goes out", "set up a webhook for new…
competition-graphql-rpc-drift
Internal downstream skill for ctf-sandbox-orchestrator. CTF-sandbox workflow for GraphQL schemas, persisted queries, RPC manifests, generated clients, OpenAPI drift, hidden operations, and contract-to-handler mismatches. Use when the user asks to inspect GraphQL or RPC requests, compare client contracts to live…