Essentials

Name: Essentials
Author: fieldcure

by fieldcureversion 2.6.1i★ –iRuns on your computer

Registry nameio.github.fieldcure/essentials

Install

Overview

Description from the maker (original English)

Essential MCP server: HTTP, web search, downloads, Wolfram|Alpha, shell, JS, file I/O, memory.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: 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

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into 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"
      }
    }
  }
}

Run this in your 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 --yes

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.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"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "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"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

ESSENTIALS_SEARCH_ENGINE env
ESSENTIALS_SEARCH_API_KEY env
SERPER_API_KEY env
SERPAPI_API_KEY env
TAVILY_API_KEY env
WOLFRAM_APPID env
ESSENTIALS_MEMORY_PATH env
ESSENTIALS_DOWNLOAD_DIRECTORY env
ESSENTIALS_SETTINGS_PATH env

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account fieldcure, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Search & AI memoryi

More stars than 0% of the other 7229 servers in this category
Published to the registry more recently than 14% of the other 7229 servers in this category
Basic checks equal to or better than 100% of the other 7229 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Essentials safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (2.6.1) reached the registry 5 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need .NET on your computer.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago

Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago

Install

Exa

by exa-labs

Connect AI agents to Exa for web search, content fetching, and multi-step research.

Runs in the cloud★ 5,213MITUpdated 44 days ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

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_fetch and read_file extract 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 use fieldcure-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	`.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, not developer.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, never 6e14
Single-letter variables (x, y, n)
Named physical constants ('speed of light', not 299792458)
For equations with units, solve without units first
RECOMMENDED / AVOID hints steer the model — simple arithmetic to run_javascript, general web queries to web_search, subjective/news questions away from Wolfram

Only the beginning is shown; read the rest in the repo

Essentials

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

FieldCure MCP Essentials

Features

Installation

From source

Requirements

Tools

Category Search (SerpApi / Serper / Tavily)

Runtime engine switching

web_search vs web_fetch vs download_file vs http_request

Document Parsing

File Downloads

Web Search

Use Tavily

Or via environment variables

Environment Variable Auto-Detection

API Key Security

Region

Explicit paid engine without a key — MCP Elicitation

Wolfram|Alpha

AppID

Query tips (surfaced in the tool description)

`web_search` vs `web_fetch` vs `download_file` vs `http_request`