Context7
Up-to-date docs for AI agents
Descripción del creador (original en inglés)
Web search (Brave) and SSRF-safe page fetching, extraction and comparison for agents
Estos tres nunca se combinan en una sola puntuación: las opiniones, las mediciones y la popularidad son cosas distintas.
Todavía no escribimos un resumen sencillo para este. Abajo están los datos que leímos del registro.
Elige la app de IA que usas y copia la configuración.
BRAVE_SEARCH_API_KEY, WEB_RESEARCH_SEARCH_PROVIDER, USER_AGENT, SEARCH_CACHE_TTL, PAGE_CACHE_TTL, FETCH_TIMEOUT_MS, MAX_HTML_SIZELos valores marcados como secretos son llaves de tu cuenta. Nunca los compartas ni los pegues en un chat.
Necesitas
¿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": {
"web-research": {
"command": "npx",
"args": [
"-y",
"@opafex/mcp-web-research"
],
"env": {
"BRAVE_SEARCH_API_KEY": "your-value",
"WEB_RESEARCH_SEARCH_PROVIDER": "your-value",
"USER_AGENT": "your-value",
"SEARCH_CACHE_TTL": "your-value",
"PAGE_CACHE_TTL": "your-value",
"FETCH_TIMEOUT_MS": "your-value",
"MAX_HTML_SIZE": "your-value"
}
}
}
}Ejecuta esto en tu terminal
claude mcp add web-research --env BRAVE_SEARCH_API_KEY=your-value --env WEB_RESEARCH_SEARCH_PROVIDER=your-value --env USER_AGENT=your-value --env SEARCH_CACHE_TTL=your-value --env PAGE_CACHE_TTL=your-value --env FETCH_TIMEOUT_MS=your-value --env MAX_HTML_SIZE=your-value -- npx -y @opafex/mcp-web-researchCompleta los valores vacíos antes de ejecutarlo.
Pégalo en .cursor/mcp.json de tu proyecto, o en ~/.cursor/mcp.json
{
"mcpServers": {
"web-research": {
"command": "npx",
"args": [
"-y",
"@opafex/mcp-web-research"
],
"env": {
"BRAVE_SEARCH_API_KEY": "your-value",
"WEB_RESEARCH_SEARCH_PROVIDER": "your-value",
"USER_AGENT": "your-value",
"SEARCH_CACHE_TTL": "your-value",
"PAGE_CACHE_TTL": "your-value",
"FETCH_TIMEOUT_MS": "your-value",
"MAX_HTML_SIZE": "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.
Pégalo en .vscode/mcp.json de tu proyecto
{
"servers": {
"web-research": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@opafex/mcp-web-research"
],
"env": {
"BRAVE_SEARCH_API_KEY": "your-value",
"WEB_RESEARCH_SEARCH_PROVIDER": "your-value",
"USER_AGENT": "your-value",
"SEARCH_CACHE_TTL": "your-value",
"PAGE_CACHE_TTL": "your-value",
"FETCH_TIMEOUT_MS": "your-value",
"MAX_HTML_SIZE": "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.
WEB_RESEARCH_SEARCH_PROVIDER envUSER_AGENT envSEARCH_CACHE_TTL envPAGE_CACHE_TTL envFETCH_TIMEOUT_MS envMAX_HTML_SIZE envEsta configuración se genera a partir de la ficha del creador en el registro. Si el README dice otra cosa, sigue el README.
Se ejecuta en tu computadora; la lista de herramientas aparece en tu app de IA después de instalarlo.
Revisamos información que cualquiera puede ver; no hemos leído el código. Las revisiones que no aplican no se cuentan. · Revisado el 7 nov 2026
El nombre en el registro se verificó con la cuenta de GitHub opafex, dueña del repo
Todavía no hemos leído este repo en GitHub
Todavía no hemos leído este repo en GitHub
Este se ejecuta en tu computadora; no hay endpoint en internet
Se ejecuta en tu computadora y usa ajustes locales en su lugar
Se ejecuta en tu computadora; solo podemos leer listas de herramientas de endpoints en internet
Comparado con todos los servidores activos de esta categoría en el registro. Las estrellas solo cuentan cuando quien lo publica es dueño del repo.
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.
Debes completar: BRAVE_SEARCH_API_KEY
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).
El repo de GitHub cambió por última vez –, y la última versión (0.1.0) llegó al registro hace 13 días.
Las apps compatibles con MCP, como Claude Desktop, Claude Code, Cursor y VS Code. También necesitas Node.js en tu computadora.
En la misma categoría: Context7, Codebase Memory, Exa
Servidores de la misma categoría hechos por otros creadores, ordenados por estrellas.
Cómo leer una tarjeta:★ Estrellas de GitHubiTres pilares: reseñas · revisiones · usoiActualizado = fecha en que se publicó la última versión en el registroi
Up-to-date docs for AI agents
Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.
Connect AI agents to Exa for web search, content fetching, and multi-step research.
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.
MCP server for web research — search the web, fetch pages as clean text, pull named sections out of a page, compare pages side by side, and run a two-stage "search then read the top results" pass.
No LLM is involved: research_topic and compare_pages organise extracted text, they do not generate it. Every page fetch is SSRF-checked, including every redirect hop.
Search uses the Brave Search API (free tier available). Without a key, the four page tools still work and the two search tools return an error telling you which variable to set.
npx -y @opafex/mcp-web-research
Requires Node.js 20+. No other dependencies to install.
claude mcp add web-research -e BRAVE_SEARCH_API_KEY=your-key -- npx -y @opafex/mcp-web-research
Or add it to .mcp.json in your project root:
{
"mcpServers": { "web-research": { "command": "npx", "args": ["-y", "@opafex/mcp-web-research"], "env": { "BRAVE_SEARCH_API_KEY": "your-key" } } } }
Add the same block to claude_desktop_config.json (Settings → Developer → Edit Config):
{
"mcpServers": { "web-research": { "command": "npx", "args": ["-y", "@opafex/mcp-web-research"], "env": { "BRAVE_SEARCH_API_KEY": "your-key" } } } }
Omit BRAVE_SEARCH_API_KEY to run with the page tools only.
| Tool | What it does | Needs a search provider |
|---|---|---|
web_search | Search the web; returns title, URL and snippet per result | Yes |
fetch_webpage | Fetch a URL and return its title and clean text, links, or both | No |
research_topic | Search a topic, fetch the top results, and compile the key sentences from each, by source | Yes |
extract_structured_data | Fetch a page and return the section around each requested field (e.g. pricing, contact) | No |
compare_pages | Fetch 2–5 pages and compare them, optionally around one focus area | No |
server_info | Server name, version, tools and resources (built in, from @opafex/mcp-shared) | No |
web_search| Parameter | Type | Required | Description |
|---|---|---|---|
query | string | Yes | Search query |
maxResults | number | No | 1–20, default 10 |
domain | string | No | Restrict results to this domain (e.g. "example.com"); adds site: and filters the result URLs |
Result URLs that fail the SSRF check (below) are dropped before they are returned.
Example response
[
{ "title": "Model Context Protocol", "url": "https://modelcontextprotocol.io/", "snippet": "An open protocol that enables seamless integration between LLM applications and external data sources and tools." } ]
</details>
fetch_webpage| Parameter | Type | Required | Description | ||
|---|---|---|---|---|---|
url | string | Yes | http or https URL | ||
extractMode | "text" \ | "links" \ | "all" | No | Default "text" |
maxLength | number | No | Maximum characters of text returned, default 4000 |
Scripts, styles, and are removed. finalUrl is included when the page was reached through redirects.
Example response
{
"title": "Example Domain", "text": "Example Domain\nThis domain is for use in illustrative examples in documents.", "url": "http://example.com/", "fetchedAt": "2026-10-24T12:00:00.000Z" }
</details>
research_topic| Parameter | Type | Required | Description | ||
|---|---|---|---|---|---|
topic | string | Yes | What to research | ||
depth | "quick" \ | "standard" \ | "deep" | No | Search 3 / 5 / 10 results and read 2,000 / 4,000 / 8,000 characters of each. Default "standard" |
maxSources | number | No | 1–10 sources to fetch, default 5 |
Key points are the sentences that mention the topic's words, up to five per source. A source that cannot be fetched falls back to its search snippet.
extract_structured_data| Parameter | Type | Required | Description |
|---|---|---|---|
url | string | Yes | Page to read |
fields | string[] | Yes | Field names to look for (e.g. ["pricing", "features", "contact"]) |
For each field, returns the first line mentioning it and the ten lines after, up to 1,000 characters — or No " " section found on page. This is heading matching, not a schema extractor.
compare_pages| Parameter | Type | Required | Description |
|---|---|---|---|
urls | string[] | Yes | 2–5 URLs |
focus | string | No | A field to pull from every page (e.g. "pricing") |
A page that fails to fetch is listed with "(fetch failed)" and the reason; the others are still compared.
| Resource | Description |
|---|---|
web-research://status | Search provider in use (or why search is unavailable), cache stats and configuration |
web-research://cache | Search queries currently cached |
| Provider | How to select | Notes |
|---|---|---|
| Brave Search API (recommended) | Set BRAVE_SEARCH_API_KEY | An official API with a free tier. Up to 20 results per query. |
| DuckDuckGo HTML scraper | Set WEB_RESEARCH_SEARCH_PROVIDER=duckduckgo | Opt-in only — see below |
| none | Neither of the above | web_search and research_topic return an error naming BRAVE_SEARCH_API_KEY; the other tools work |
About the DuckDuckGo option. It parses the results page at html.duckduckgo.com. That is not an API: it breaks whenever DuckDuckGo changes its markup, it may be rate-limited or blocked, and DuckDuckGo's terms do not permit automated querying. It sends this server's honest user agent rather than pretending to be a browser, which makes blocking more likely. It is kept for personal experimentation; if you turn it on, you are responsible for complying with DuckDuckGo's terms. Use Brave for anything you depend on.
| Variable | Type | Default | Description | |
|---|---|---|---|---|
BRAVE_SEARCH_API_KEY | string | — | Brave Search API key. Enables web_search and research_topic | |
WEB_RESEARCH_SEARCH_PROVIDER | brave \ | duckduckgo | Brave if a key is set, else none | Choose the search provider explicitly |
USER_AGENT | string | opafex-mcp-web-research/ (+https://github.com/Opafex/opafex-mcps) | User-Agent sent with every request | |
FETCH_TIMEOUT_MS | number | 10000 | Timeout per page, across all its redirect hops | |
MAX_HTML_SIZE | number (bytes) | 1000000 | Bytes read from a page body; the download stops there | |
SEARCH_CACHE_TTL | number (seconds) | 900 (15 min) | How long search results are cached | |
PAGE_CACHE_TTL | number (seconds) | 3600 (1 h) | How long fetched pages are cached |
The page tools fetch URLs chosen by a model, from the machine the server runs on. Without protection, that machine's private network and cloud metadata service are one tool call away (server-side request forgery). Every fetch is checked first, and refused if:
http or https;localhost, *.localhost, or a cloud metadata name (metadata.google.internal);http://2130706433/, http://0x7f.1/) are normalised before the check;Blocked ranges:
| IPv4 | IPv6 |
|---|---|
0.0.0.0/8 this network | :: unspecified, ::1 loopback |
10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 private | fc00::/7 unique local |
100.64.0.0/10 carrier-grade NAT | fe80::/10 link-local, fec0::/10 site-local |
127.0.0.0/8 loopback | ff00::/8 multicast |
169.254.0.0/16 link-local, incl. cloud metadata 169.254.169.254 | ::ffff:0:0/96 IPv4-mapped — judged by the IPv4 address inside |
192.0.0.0/24, 198.18.0.0/15 reserved / benchmarking | 64:ff9b::/96 NAT64 and 2002::/16 6to4 — judged by the IPv4 address inside |
192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24 documentation | ::/96 IPv4-compatible, 64:ff9b:1::/48, 2001::/32 Teredo, 2001:db8::/32 |
224.0.0.0/4 multicast, 240.0.0.0/4 reserved, broadcast | anything outside global unicast 2000::/3 |
Redirects are followed by hand, and every hop is checked again — at most 5 hops. A public page that redirects to http://169.254.169.254/ is refused before the second request is made. Search result URLs are checked too, and dropped if they fail.
Known limit — DNS rebinding. The check resolves the hostname, then fetch resolves it again to connect. A hostile DNS server with a very short TTL could answer the two lookups differently. Closing that gap means pinning the connection to the checked address, which Node's built-in fetch does not expose without an extra dependency. If this server runs somewhere with sensitive internal services, also limit what it can reach at the network level (container network policy, egress firewall).
text/*, application/xhtml+xml or application/json; PDFs, images and other binary types are refused.research_topic key points and extract_structured_data sections are keyword matching, not understanding.npm run build # Compile TypeScript
npm run dev # Run with tsx (no build needed) npm test # Run tests (no network — fetch and DNS are faked) npm start # Run compiled server
Found a bug or have a feature request? Open an issue.
Pull requests welcome — see the main repo for development setup.
MIT — see LICENSE.