Atomicapis Mcp Server

AtomicAPIs MCP Server

[](https://modelcontextprotocol.io) [](https://dotnet.microsoft.com) [](LICENSE) []()

A Model Context Protocol (MCP) server that exposes 17 production-grade micro-API tools for AI assistants. Built with .NET 9 and the official ModelContextProtocol SDK.

MCP allows AI assistants like Claude to invoke these tools natively during conversation — no HTTP requests, API keys, or boilerplate needed on the client side.

Quick Install

One-click for Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "atomicapis": {
      "command": "dotnet",
      "args": ["run", "--project", "/path/to/atomicapis-mcp-server/src"]
    }
  }
}

One-click for Claude Code

claude mcp add atomicapis -- dotnet run --project /path/to/atomicapis-mcp-server/src

One-click for Kiro

[](https://github.com/Benzene66/atomicapis-mcp-server)

Tools

| Tool | Method | Description | |------|--------|-------------| | WebToMarkdownTools | ExtractMarkdown | Scrape any URL and convert the page to clean Markdown. Strips nav, footer, scripts, and non-essential HTML to minimize tokens. SSRF-protected with a 5MB page limit. | | EmailShieldTools | VerifyEmail | Check if an email address is disposable or from a known burner domain. Validates format, checks against a curated domain list, and verifies MX records via DNS. | | TimezoneTools | ResolveTimezone | Convert latitude/longitude to full timezone data including IANA timezone, UTC offset, DST status, current local time, and next transition. | | SchemaSniffTools | InferSchema | Auto-detect the format (JSON, CSV, XML) of a payload and infer its schema — field names, types, nullability, and nesting. | | ProductSchemaTools | GenerateProductSchema | Generate JSON-LD Product structured data for SEO. Outputs both raw JSON-LD and a ready-to-embed ` tag. | | **CsvSurgeonTools** | CleanCsv | Clean, normalize, and deduplicate CSV data. Fixes encoding, normalizes headers, collapses whitespace, pads/truncates rows, and optionally normalizes date formats. | | **UtmLinkTools** | CloakLink | Create cloaked UTM-tagged tracking URLs. Encode campaign parameters into a short token and decode them back. | | **JsonRepairTools** | RepairJson | Fix broken JSON from LLM outputs — trailing commas, unquoted keys, single quotes, missing brackets. Optionally validate against a JSON schema. | | **TokenCounterTools** | CountTokens | Count tokens for multiple LLM models (GPT-4, Claude, Llama, Mistral, Gemini). Estimates costs, context window usage, and flags when text exceeds the model's limit. | | **EmailAuthGraderTools** | GradeEmailAuth | Audit a domain's email authentication setup: SPF, DKIM, DMARC, MTA-STS, and BIMI. Returns a letter grade (A–F), score, and actionable recommendations. | | **PiiRedactorTools** | RedactPii | Detect and redact personally identifiable information from text. Handles emails, SSNs, credit cards, phone numbers, IP addresses, street addresses, dates of birth, and URLs. | | **PhoneValidatorTools** | ValidatePhone | Validate international phone numbers across 30+ countries. Returns E.164 format, country info, number type (mobile/landline), and formatted output. | | **TaxIdValidatorTools** | ValidateTaxId | Validate VAT and Tax IDs for EU, US, UK, Australia, and India. EU VAT numbers are verified against the VIES service when available. | | **PromptInjectionTools** | DetectPromptInjection | Score text for prompt injection and jailbreak attempts. Uses pattern matching and heuristic analysis across multiple attack categories. Returns a risk score (0–100) with flagged spans. | | **SemanticSearchTools** | SemanticSearch | Match a search query against a catalog of items using TF-IDF similarity. Supports fuzzy matching, synonym expansion, and configurable title weighting. | | **RelatedContentTools** | FindRelatedContent | Find related content items from a corpus using TF-IDF and Jaccard similarity. Configurable thresholds, category boosting, and optional score breakdowns. | | **VoiceTaskParserTools** | ParseTasks` | Extract actionable tasks from voice transcripts. Identifies action verbs, assignees, priorities, deadlines, and confidence scores. Handles up to 100,000 characters. |

Getting Started

Prerequisites

• .NET 9 SDK

Build

cd src
dotnet build

Run

cd src
dotnet run

The server communicates over stdio using the MCP JSON-RPC protocol. It is designed to be launched by an MCP-compatible client (e.g., Claude Desktop, Claude Code, Kiro, or any MCP host). See [Quick Install](#quick-install) above for configuration.

Architecture

src/
├── Program.cs              # MCP server entry point (stdio transport)
├── Tools/                  # MCP tool definitions (17 tools)
│   ├── WebToMarkdownTools.cs
│   ├── EmailShieldTools.cs
│   ├── TimezoneTools.cs
│   └── ...
└── Engines/                # Core logic (pure computation, no HTTP/DI concerns)
    ├── CsvCleaner.cs
    ├── SchemaInferrer.cs
    ├── EmailValidator.cs
    └── ...

Tools define the MCP interface — parameter descriptions, validation, and response formatting. Each tool delegates to an Engine class that contains the pure business logic with no framework dependencies.

Dependencies

| Package | Version | Purpose | |---------|---------|---------| | ModelContextProtocol | 1.1.0 | MCP SDK for .NET | | Microsoft.Extensions.Hosting | 9.0.6 | Host builder for DI and lifecycle | | HtmlAgilityPack | 1.12.4 | HTML parsing (Web-to-Markdown) | | ReverseMarkdown | 5.2.0 | HTML-to-Markdown conversion | | GeoTimeZone | 6.1.0 | Coordinate-to-timezone lookup | | DnsClient | 1.8.0 | DNS queries (email auth grading) |

License

MIT

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Benzene66
• Source: Benzene66/atomicapis-mcp-server
• License: MIT
• Homepage: https://api.atomicapis.dev/pages/index.html

Install and usage instructions live in the source repository linked above.