MCP server

Call tools, read resources and render prompts on a remote MCP server.

Connect any MCP server that speaks Streamable HTTP: point the connection at its endpoint (with an optional access token), then discover its tools, call them with JSON arguments, read its resources, and render its prompts. Every call-tool invocation is treated as a write - the remote server's read-only claims are not verified. Requests never leave the configured server's host.

Connect

Credential field	Required	Where it comes from
Access token (ACCESS_TOKEN)	No	Optional pre-issued token for the server. Leave empty for open or internal servers.

Setting	Required	What it is
Server URL (SERVER_URL)	Yes	The MCP server's Streamable HTTP endpoint, e.g. https://mcp.example.com/mcp - every request stays on its host
Auth header name (AUTH_HEADER)	No	Header the access token is sent under (default Authorization, as “Bearer <token>”; a custom name sends the token verbatim)
Request timeout (ms) (TIMEOUT_MS)	No

Tools

Tool	Access	What it does
Ping server (yekar.mcp.ping)	Read	Check the connection: runs the MCP handshake and a ping against the configured server, reporting its name, version, negotiated protocol version, and advertised capabilities. Use it to verify the URL and credentials before anything else.
List tools (yekar.mcp.list-tools)	Read	Discover the tools the connected MCP server exposes - names, descriptions and input schemas for Call tool. Paginated via nextCursor; pages above 200 entries are cut and flagged. The annotations field carries the SERVER'S OWN claims (e.g. readOnlyHint) and is not verified - Call tool treats every invocation as a write regardless.
Call tool (yekar.mcp.call-tool)	Write	Invoke one tool on the connected MCP server with JSON arguments. ALWAYS treated as a write needing the usual write handling - the server's readOnlyHint claims are not verified, so approval fails closed. Text results are truncated with disclosure; image/binary results are saved as session files.
List resources (yekar.mcp.list-resources)	Read	List the resources (files, records, documents) the connected MCP server exposes - the uris Read resource takes. Paginated via nextCursor; oversized pages are cut and flagged.
Read resource (yekar.mcp.read-resource)	Read	Read one resource by uri. Text contents come back inline (truncated with disclosure); binary contents are saved as session files (refused above 10485760 bytes).
List prompts (yekar.mcp.list-prompts)	Read	List the prompt templates the connected MCP server offers - names and declared arguments for Get prompt. Paginated via nextCursor; oversized pages are cut and flagged.
Get prompt (yekar.mcp.get-prompt)	Read	Render one of the server's prompt templates with arguments. Returns the resulting messages flattened to labeled text (role: content), truncated with disclosure when long.

Notes

• One connection = one MCP server. The server URL is the Streamable HTTP endpoint (usually ending in /mcp); requests are egress-locked to its host.
• Use Ping server first to verify the URL and token, then List tools to discover what the server offers before calling anything.
• Every Call tool invocation is treated as a WRITE regardless of what the server claims about a tool - remote annotations are unverified, so approval fails closed.
• Servers requiring MCP's OAuth sign-in flow are not supported yet - paste a pre-issued token instead (sent as a Bearer by default, or under the custom header name you configure).