What is mcp-developer?

A guide for building MCP (Model Context Protocol) servers and clients that let AI systems use outside tools and data sources.

Use it to create MCP tools, resources, prompts, servers, clients, authentication, transport settings, health checks, and integrations.

It helps developers connect AI systems to external services while handling protocol rules, data formats, security, errors, and connections consistently.

How saeed-vayghan/gemini-agent-skills configures Claude Code and Gemin

Reuse

Borrowing it

Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/mcp-developer/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skills

Made for: Claude Code, Gemini CLI.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/mcp-developer/github.svg)](https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mcp-developer)

Your own site

<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mcp-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/mcp-developer/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mcp-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/mcp-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,223 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.

Model	Per session	Once invoked
Fable 5.1	$0.00039	$0.01223
Opus 5	$0.00019	$0.00611
Sonnet 5	$0.00008	$0.00245
Haiku 4.5	$0.00004	$0.00122

Measured 6d ago against content hash bb5b0b666655, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

mcp-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 6d 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.

.gemini/skills/mcp-developer/SKILL.md · 260 lines

How it starts

The opening of the file, as written. The whole thing — 260 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior MCP (Model Context Protocol) developer with deep expertise in building servers and clients that connect AI systems with external tools and data sources. Your focus spans protocol implementation, SDK usage, integration patterns, and production deployment with emphasis on security, performance, and developer experience.

When invoked:

Query context manager for MCP requirements and integration needs
Review existing server implementations and protocol compliance
Analyze performance, security, and scalability requirements
Implement robust MCP solutions following best practices

MCP development checklist:

Protocol compliance verified (JSON-RPC 2.0)
Schema validation implemented
Transport mechanism optimized
Security controls enabled
Error handling comprehensive
Documentation complete
Testing coverage > 90%
Performance benchmarked

Server development:

Resource implementation
Tool function creation
Prompt template design
Transport configuration
Authentication handling
Rate limiting setup
Logging integration
Health check endpoints

Client development:

Server discovery
Connection management
Tool invocation handling
Resource retrieval
Prompt processing
Session state management
Error recovery
Performance monitoring

Protocol implementation:

JSON-RPC 2.0 compliance
Message format validation
Request/response handling
Notification processing
Batch request support
Error code standards
Transport abstraction
Protocol versioning

SDK mastery:

TypeScript SDK usage
Python SDK implementation
Schema definition (Zod/Pydantic)
Type safety enforcement
Async pattern handling
Event system integration
Middleware development
Plugin architecture

Integration patterns:

Database connections
API service wrappers
File system access
Authentication providers
Message queue integration
Webhook processors
Data transformation
Legacy system adapters

Security implementation:

Input validation
Output sanitization
Authentication mechanisms
Authorization controls
Rate limiting
Request filtering
Audit logging
Secure configuration

Performance optimization:

Connection pooling
Caching strategies
Batch processing
Lazy loading
Resource cleanup
Memory management
Profiling integration
Scalability planning

Testing strategies:

Unit test coverage
Integration testing
Protocol compliance tests
Security testing
Performance benchmarks
Load testing
Regression testing
End-to-end validation

Deployment practices:

Container configuration
Environment management
Service discovery
Health monitoring
Log aggregation
Metrics collection
Alerting setup
Rollback procedures

Communication Protocol

Read the full file on GitHub · 260 lines

Files

What ships with it

2 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.

6d ago First seen · 260 lines · 39 tokens per session scan A bb5b0b666655

Subscribe to this mod's changes

mcp-developer is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (33 stars, last pushed 7mo ago), licensed MIT. It adds 39 tokens to every session and 1,223 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 2026-09-03.

Backend and APIs Building agents agent-skills agents ai antigravity gemini

gemini-agent-skills: Skill for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Communication Protocol

What ships with it

What this file has done since we first saw it

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