Essentials
Resumen
Descripción del creador (original en inglés)
Essential MCP server: HTTP, web search, downloads, Wolfram|Alpha, shell, JS, file I/O, memory.
Los tres pilares de PopNx MCP
Estos tres nunca se combinan en una sola puntuación: las opiniones, las mediciones y la popularidad son cosas distintas.
- Opinión de usuariosiAún no hay reseñasLas reseñas se abrirán junto con las cuentas en una etapa posterior
- Nuestras revisiones básicasi1 de 1 superadasRevisado con información pública; el código aún no se ha escaneado
- UsoiMuy nuevo★ –
Qué puedes hacer con él
Todavía no escribimos un resumen sencillo para este. Abajo están los datos que leímos del registro.
- Conexión: Se ejecuta en tu computadora
- Transporte: stdio
- Categoría: Búsqueda y memoria de IA
Instalación
Elige la app de IA que usas y copia la configuración.
Antes de instalar
- Revisiones básicas: 1 de 1 superadas
- Se ejecuta en tu computadora con los permisos de tu usuario (archivos, red, apps).
- Debes completar tú:
ESSENTIALS_SEARCH_ENGINE,ESSENTIALS_SEARCH_API_KEY,SERPER_API_KEY,SERPAPI_API_KEY,TAVILY_API_KEY,WOLFRAM_APPID,ESSENTIALS_MEMORY_PATH,ESSENTIALS_DOWNLOAD_DIRECTORY,ESSENTIALS_SETTINGS_PATH
¿Qué app usas?
Elige tu app arriba. La recordamos, así que la próxima vez el botón dirá “Instalar en …”.
Abre Claude Desktop → Settings → Developer → Edit Config y pega esto en claude_desktop_config.json
{
"mcpServers": {
"essentials": {
"command": "dnx",
"args": [
"FieldCure.Mcp.Essentials",
"--yes"
],
"env": {
"ESSENTIALS_SEARCH_ENGINE": "your-value",
"ESSENTIALS_SEARCH_API_KEY": "your-value",
"SERPER_API_KEY": "your-value",
"SERPAPI_API_KEY": "your-value",
"TAVILY_API_KEY": "your-value",
"WOLFRAM_APPID": "your-value",
"ESSENTIALS_MEMORY_PATH": "your-value",
"ESSENTIALS_DOWNLOAD_DIRECTORY": "your-value",
"ESSENTIALS_SETTINGS_PATH": "your-value"
}
}
}
}Ejecuta esto en tu terminal
claude mcp add essentials --env ESSENTIALS_SEARCH_ENGINE=your-value --env ESSENTIALS_SEARCH_API_KEY=your-value --env SERPER_API_KEY=your-value --env SERPAPI_API_KEY=your-value --env TAVILY_API_KEY=your-value --env WOLFRAM_APPID=your-value --env ESSENTIALS_MEMORY_PATH=your-value --env ESSENTIALS_DOWNLOAD_DIRECTORY=your-value --env ESSENTIALS_SETTINGS_PATH=your-value -- dnx FieldCure.Mcp.Essentials --yesCompleta los valores vacíos antes de ejecutarlo.
O copia la configuración tú
Pégalo en .cursor/mcp.json de tu proyecto, o en ~/.cursor/mcp.json
{
"mcpServers": {
"essentials": {
"command": "dnx",
"args": [
"FieldCure.Mcp.Essentials",
"--yes"
],
"env": {
"ESSENTIALS_SEARCH_ENGINE": "your-value",
"ESSENTIALS_SEARCH_API_KEY": "your-value",
"SERPER_API_KEY": "your-value",
"SERPAPI_API_KEY": "your-value",
"TAVILY_API_KEY": "your-value",
"WOLFRAM_APPID": "your-value",
"ESSENTIALS_MEMORY_PATH": "your-value",
"ESSENTIALS_DOWNLOAD_DIRECTORY": "your-value",
"ESSENTIALS_SETTINGS_PATH": "your-value"
}
}
}
}Tu navegador te pide permiso para abrir la app; luego la app muestra la configuración y te pide confirmar. Los valores de las claves quedan vacíos para que los completes tú.
O copia la configuración tú
Pégalo en .vscode/mcp.json de tu proyecto
{
"servers": {
"essentials": {
"type": "stdio",
"command": "dnx",
"args": [
"FieldCure.Mcp.Essentials",
"--yes"
],
"env": {
"ESSENTIALS_SEARCH_ENGINE": "your-value",
"ESSENTIALS_SEARCH_API_KEY": "your-value",
"SERPER_API_KEY": "your-value",
"SERPAPI_API_KEY": "your-value",
"TAVILY_API_KEY": "your-value",
"WOLFRAM_APPID": "your-value",
"ESSENTIALS_MEMORY_PATH": "your-value",
"ESSENTIALS_DOWNLOAD_DIRECTORY": "your-value",
"ESSENTIALS_SETTINGS_PATH": "your-value"
}
}
}
}Tu navegador te pide permiso para abrir la app; luego la app muestra la configuración y te pide confirmar. Los valores de las claves quedan vacíos para que los completes tú.
Este se ejecuta en tu computadora, y ChatGPT solo puede conectarse a servidores en internet. Elige otra app.
Tu elección se guarda en una cookie en este dispositivo; no necesitas cuenta.
Valores que debes completar
ESSENTIALS_SEARCH_ENGINEenvESSENTIALS_SEARCH_API_KEYenvSERPER_API_KEYenvSERPAPI_API_KEYenvTAVILY_API_KEYenvWOLFRAM_APPIDenvESSENTIALS_MEMORY_PATHenvESSENTIALS_DOWNLOAD_DIRECTORYenvESSENTIALS_SETTINGS_PATHenv
Esta configuración se genera a partir de la ficha del creador en el registro. Si el README dice otra cosa, sigue el README.
Qué puede hacer
Se ejecuta en tu computadora; la lista de herramientas aparece en tu app de IA después de instalarlo.
Revisiones básicasi
Revisamos información que cualquiera puede ver; no hemos leído el código. Las revisiones que no aplican no se cuentan. · Revisado el 8 nov 2026
- ✓ Superada
El creador coincide con el repo
El nombre en el registro se verificó con la cuenta de GitHub fieldcure, dueña del repo
- … Aún sin revisar
Sigue en mantenimiento
Todavía no hemos leído este repo en GitHub
- … Aún sin revisar
Tiene licencia
Todavía no hemos leído este repo en GitHub
- – No aplica
El endpoint responde
Este se ejecuta en tu computadora; no hay endpoint en internet
- – No aplica
Inicio de sesión con OAuth
Se ejecuta en tu computadora y usa ajustes locales en su lugar
- … Aún sin revisar
Sin instrucciones ocultas en las descripciones de herramientas
Se ejecuta en tu computadora; solo podemos leer listas de herramientas de endpoints en internet
Comparado con otros en Búsqueda y memoria de IAi
- Más estrellas que el 0% de los otros 5684 servidores de esta categoría
- Publicado en el registro más recientemente que el 14% de los otros 5684 servidores de esta categoría
- Revisiones básicas iguales o mejores que el 100% de los otros 5684 servidores de esta categoría
Comparado con todos los servidores activos de esta categoría en el registro. Las estrellas solo cuentan cuando quien lo publica es dueño del repo.
Preguntas frecuentes
¿Es seguro Essentials?
Superó 1 de 1 revisiones básicas aplicables. No hemos leído el código. Antes de agregar una clave o un token, revisa qué acceso pide el servidor y usa una clave que tenga solo los permisos que necesitas.
¿Qué claves o códigos necesita?
El registro no indica ninguna clave obligatoria, aunque algunos servidores te piden iniciar sesión la primera vez que los usas.
¿Se ejecuta en mi computadora o en la nube?
Se ejecuta en tu computadora. Tu app de IA lo inicia cuando hace falta, y los datos no pasan por los servidores del creador (a menos que el propio servidor llame a un servicio en línea).
¿Sigue en mantenimiento?
El repo de GitHub cambió por última vez –, y la última versión (2.6.1) llegó al registro hace 6 meses.
¿Qué apps pueden usarlo?
Las apps compatibles con MCP, como Claude Desktop, Claude Code, Cursor y VS Code. También necesitas .NET en tu computadora.
¿Qué puedo usar en su lugar?
En la misma categoría: Context7, Codebase Memory, Exa
Alternativas
Servidores de la misma categoría hechos por otros creadores, ordenados por estrellas.
Cómo leer una tarjeta:↓ Descargas por semanai★ Estrellas de GitHubiTres pilares: reseñas · revisiones · usoiActualizado = fecha en que se publicó la última versión en el registroi
Codebase Memory
Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.
Exa
Connect AI agents to Exa for web search, content fetching, and multi-step research.
README del creador
Abrir el README
Copiado tal cual del repo del creador. PopNx MCP no lo ha revisado ni lo respalda. Se quitaron HTML, imágenes y scripts. Los enlaces llevan fuera de este sitio.
FieldCure MCP Essentials
Install once, get the basics. A Model Context Protocol (MCP) server that provides 20 essential tools — HTTP requests, web search & fetch, URL file downloads, Wolfram|Alpha computational knowledge, shell commands, JavaScript execution, file I/O, environment info, and persistent memory — for any MCP client. Category search (news, images, scholar, patents) and runtime engine switching (get/set) are always available; capabilities are guarded at invocation time against the active engine. Built with C# and the official MCP C# SDK.
Features
- 20 essential tools — HTTP, web search & fetch, URL file downloads, runtime search-engine switching (get/set), Wolfram|Alpha, shell, JavaScript sandbox, environment info, file read/write/search, persistent memory + category search (news, images, scholar, patents)
- Zero configuration — no API keys needed for default Bing search; optional API keys unlock Serper, Tavily, SerpApi (+ category search tools), and Wolfram|Alpha
- Document parsing —
web_fetchandread_fileextract text from PDF, DOCX, HWPX, PPTX, XLSX into Markdown. PDF text extraction is text-layer only; scanned PDFs without a text layer yield empty text. For OCR-backed indexing usefieldcure-mcp-rag. - Sandboxed JavaScript — Jint engine with strict limits (timeout, statement count, recursion depth)
- SSRF protection — HTTP requests, web fetch, and file downloads block private IP ranges and loopback addresses
- Cross-client — works with Claude Desktop, VS Code, AssistStudio, and any MCP-compatible client
- Stdio transport — standard MCP subprocess model via JSON-RPC over stdin/stdout
Installation
dotnet tool install -g FieldCure.Mcp.Essentials
After installation, the fieldcure-mcp-essentials command is available globally.
From source
git clone https://github.com/fieldcure/fieldcure-mcp-essentials.git
cd fieldcure-mcp-essentials dotnet build
Requirements
- .NET 8.0 Runtime or later
Tools
| Tool | Description | Destructive |
|---|---|---|
http_request | Full HTTP client (GET/POST/PUT/DELETE/PATCH/HEAD) with custom headers and body | — |
web_search | Search the web and return snippets (title, URL, description) | — |
web_fetch | Fetch a URL and extract content as Markdown — HTML pages and documents (PDF, DOCX, HWPX, PPTX, XLSX) | — |
download_file | Download URL content to disk with a configurable download directory, 100 MB limit, and atomic save | Yes |
run_command | Execute shell commands with working directory, environment variables, shell selection, and output truncation flags | Yes |
run_javascript | Sandboxed JavaScript execution (Jint) for math, data processing, JSON, regex | — |
wolfram_alpha | Wolfram|Alpha Full Results API — symbolic math, plots, unit conversions, constants; MathML passes through for native rendering | — |
get_environment | System info — local time, timezone, OS, hostname, username, .NET version | — |
read_file | Read files — text with offset/limit, documents (PDF, DOCX, HWPX, PPTX, XLSX) parsed to Markdown | — |
write_file | Write or append text to files with auto directory creation | Yes |
search_files | Search files by glob pattern and content (grep-like) | — |
remember | Store a key-value memory (persisted in SQLite) | — |
forget | Delete memories by key or keyword search | Yes |
list_memories | Search and list stored memories with FTS5 and pagination | — |
Category Search (SerpApi / Serper / Tavily)
Always registered. Each tool runtime-guards on the active engine's capabilities and returns a descriptive error pointing at set_search_engine when the current engine does not support the category.
| Tool | Description | SerpApi | Serper | Tavily |
|---|---|---|---|---|
search_news | Search recent news articles via Google News | Yes | Yes | Yes |
search_images | Search images with size/type filtering | Yes | Yes | — |
search_scholar | Search academic papers with citation counts | Yes | Yes | — |
search_patents | Search patent documents with inventor/assignee filtering | Yes | Yes | — |
Runtime engine switching
| Tool | Description |
|---|---|
set_search_engine | Switch the active engine (bing, duckduckgo, serper, tavily, serpapi) at runtime. Paid-engine API keys resolve lazily via env var or MCP Elicitation on the next search; the switch itself takes only the engine name. Emits notifications/tools/list_changed on success. |
get_search_engine | Return the currently active engine and its category capabilities. Read-only; use this to reflect live engine state in host UIs or to check category support before calling a category search tool. |
web_search vs web_fetch vs download_file vs http_request
http_request | web_search | web_fetch | download_file | |
|---|---|---|---|---|
| Purpose | API calls, raw HTTP | Web search | Read web pages | Save original files |
| Response | Raw (JSON, HTML, etc.) | {title, url, snippet}[] | Markdown (body only) | JSON metadata with saved path |
| Conversion | None | None | SmartReader HTML → Markdown | None |
| Length limit | max_response_chars (default: unlimited, up to 1MB) | max_results (max 10) | max_length (max 20000) | 100 MB |
Document Parsing
web_fetch and read_file can parse binary documents into Markdown:
| Format | Extension | Detection |
|---|---|---|
.pdf | Content-Type / URL extension (text layer only; no OCR) | |
| Word | .docx | Content-Type / URL extension |
| Hangul (HWPX) | .hwpx | URL extension (no standard Content-Type) |
| PowerPoint | .pptx | Content-Type / URL extension |
| Excel | .xlsx | Content-Type / URL extension |
Output includes headings, tables, math expressions ([math: LaTeX]), and slide/page separators.
File Downloads
download_file saves the original bytes from an HTTP(S) URL. If save_path is omitted, the tool infers a filename from Content-Disposition, the URL path, or a generated fallback name. Relative save_path values resolve under the configured download_directory; absolute paths are used as-is except for protected system directories.
The default download directory is ~/Downloads/mcp and is created automatically on first use. Downloads are written to a temporary file in the destination directory and then committed with an atomic move/replace, so failed or cancelled downloads do not leave a partial final file.
{
"url": "https://example.com/report.pdf" }
{
"url": "https://example.com/report.pdf", "save_path": "reports/report.pdf", "overwrite": false }
Web Search
Default engine is Bing (free, no API key needed). For more reliable results, use an API-based engine:
| Engine | Free Tier | Category Search | API Key |
|---|---|---|---|
| Bing (default) | Unlimited (scraping) | — | Not needed |
| Serper | 2,500 one-time | news, images, scholar, patents | serper.dev |
| SerpApi | 100/month | news, images, scholar, patents | serpapi.com |
| Tavily | 1,000/month | news | tavily.com |
# Use Serper
fieldcure-mcp-essentials --search-engine serper --search-api-key YOUR_KEY
Use Tavily
fieldcure-mcp-essentials --search-engine tavily --search-api-key YOUR_KEY
Or via environment variables
ESSENTIALS_SEARCH_ENGINE=serper ESSENTIALS_SEARCH_API_KEY=xxx fieldcure-mcp-essentials
Environment Variable Auto-Detection
When --search-engine is omitted, the server scans environment variables and automatically selects the best available engine:
| Engine | Environment Variable |
|---|---|
| Serper | SERPER_API_KEY |
| SerpApi | SERPAPI_API_KEY |
| Tavily | TAVILY_API_KEY |
Detection priority: Serper → SerpApi → Tavily → Bing/DuckDuckGo fallback.
API Key Security
| Engine | Auth Method | Key Exposure |
|---|---|---|
| Serper | HTTP header (X-API-KEY) | Not in URL |
| Tavily | Authorization header (Bearer token) | Not in URL |
| SerpApi | URL query parameter (api_key=xxx) | Visible in server logs |
Region
Use the region parameter for localized results:
// Korean results
{ "query": "서울 맛집", "region": "ko-kr" }
// US English results { "query": "best restaurants NYC", "region": "en-us" }
// Global (default) { "query": "Python tutorial" }
Without --search-engine, a fallback engine (Bing → DuckDuckGo) auto-switches on CAPTCHA. Free engines rely on scraping and may be intermittent — an API-based engine is strongly recommended for any non-trivial use.
Explicit paid engine without a key — MCP Elicitation
When --search-engine serper|tavily|serpapi is selected explicitly but no API key is configured (CLI arg, ESSENTIALS_SEARCH_API_KEY, or engine-specific env var), the server waits until the first web_search call and then asks the MCP client for the key via MCP Elicitation. If the user declines, a follow-up prompt asks whether to run the search with free Bing/DuckDuckGo instead. Declining both lets the tool soft-fail with a clear message so the LLM can recover.
Clients without Elicitation support (including older CLI hosts) fall back to the free engine immediately, matching the pre-2.1 behaviour. Cached keys live for the process lifetime; the host can re-elicit after an upstream 401/403 if the tool invalidates the cache.
Wolfram|Alpha
wolfram_alpha calls the Full Results API v2 and returns mixed content — plaintext, MathML (passed through verbatim for clients that render MathML natively, e.g. ChatPanel/WebView2), and plot images embedded as ImageContent. The API's reinterpret=true flag is always on so most typo-level failures auto-correct server-side; only real parse failures surface isError: true with assumptions > tips > didyoumeans guidance.
AppID
Set WOLFRAM_APPID to the AppID obtained at developer.wolframalpha.com (select "Full Results API"; free tier: 2,000 calls/month, non-commercial). On MCP clients that support Elicitation the key can also be supplied interactively on first use. A rejected AppID (401/403) triggers a single invalidate-and-retry so a mistyped key can be re-elicited; the existing ApiKeyResolverRegistry re-elicit cap (2 per env-var slot) prevents loops.
⚠️ Use
developer.wolframalpha.com, notdeveloper.wolfram.com— the latter is a separate paid portal and will show "no permission to access any API keys" for free accounts.
The tool is always registered regardless of AppID status; without a key it returns a setup-guidance error so the model can inform the user instead of silently skipping.
Query tips (surfaced in the tool description)
- English only, simplified keyword form (
'France population', not'how many people live in France') - Exponent notation
6*10^14, never6e14 - Single-letter variables (
x,y,n) - Named physical constants (
'speed of light', not299792458) - For equations with units, solve without units first
RECOMMENDED / AVOIDhints steer the model — simple arithmetic torun_javascript, general web queries toweb_search, subjective/news questions away from Wolfram
Solo se muestra el principio; lee el resto en el repo