Package 'tidybrregmcp'

Description

Pure dispatcher shared by every transport. Requests return a response object; notifications return NULL. Tool execution errors are reported inside the result (isError), protocol errors as JSON-RPC errors.

Usage

mcp_handle(srv, msg)

Arguments

Value

A named list (the response) or NULL.

Examples

srv <- mcp_server()
mcp_handle(srv, list(jsonrpc = "2.0", id = 1, method = "ping"))

Description

Serialises everything a server needs to expose tidybrreg over the Model Context Protocol without running R: the tool catalogue of mcp_tools() (titles, descriptions, input and output schemas), the machine-readable endpoint contract shipped by tidybrreg (inst/extdata/endpoints.json, tested against the functions), the bundled dictionaries with their vintages, every help topic as Markdown, and the server instructions. The output is deterministic for a given installed tidybrreg (no timestamps), so the Node implementation in ⁠tidybrreg-mcp-node/⁠ commits it and CI fails when regenerating it changes anything: the non-R server changes exactly when tidybrreg does.

Usage

mcp_manifest(
  path = "tidybrreg-mcp-manifest.json",
  package = "tidybrreg",
  exclude = character()
)

Arguments

Value

The manifest as a list, invisibly when path is given.

Examples

m <- mcp_manifest(NULL)
names(m)
length(m$tools)

Description

Starts an MCP server whose tools are tidybrreg's exported functions (see mcp_tools()). Two transports are available.

Usage

mcp_serve(
  transport = c("stdio", "http"),
  host = "0.0.0.0",
  port = as.integer(Sys.getenv("PORT", "8080")),
  token = Sys.getenv("MCP_BEARER_TOKEN", ""),
  srv = NULL
)

Arguments

Value

mcp_serve() runs until the client closes the connection (stdio) or the process is interrupted (HTTP) and then returns invisible(NULL).

stdio

transport = "stdio" reads newline-delimited JSON-RPC messages from standard input and writes responses to standard output, which is what desktop clients (Claude Desktop, Claude Code, Cursor, ...) expect from a locally launched server. Log lines go to standard error. A client configuration is:

{"mcpServers": {"tidybrreg": {"command": "Rscript",
  "args": ["-e", "tidybrregmcp::mcp_serve()"]}}}

Streamable HTTP

transport = "http" serves the streamable HTTP transport with httpuv: POST /mcp carries one JSON-RPC message (or a batch) and answers with application/json; GET /mcp answers 405 because this server never pushes messages; DELETE /mcp ends a session; GET /health reports the server and the tidybrreg version. When the MCP_BEARER_TOKEN environment variable (or token) is set, every ⁠/mcp⁠ request must carry it as Authorization: Bearer.

Examples

## Not run: 
tidybrregmcp::mcp_serve()
tidybrregmcp::mcp_serve("http", port = 8080)

## End(Not run)

Description

Builds the tool catalogue and resource index from the installed tidybrreg once; transports call mcp_handle() with it for every message.

Usage

mcp_server(package = "tidybrreg", exclude = mcp_excluded())

Arguments

Value

An environment holding tools, resources, info, instructions, and initialized.

Examples

srv <- mcp_server()
length(srv$tools)

Description

Every exported function of tidybrreg becomes one tool. The tool's title, description and argument documentation are rendered from the function's installed help page, the input schema is inferred from the function's formals together with the documented argument types, and nothing is hand-written per tool. A change to tidybrreg's exports or documentation changes the catalogue the next time the server starts.

Usage

mcp_tools(package = "tidybrreg", exclude = mcp_excluded())

Arguments

Value

A named list of tool definitions, each a list with name, title, description, inputSchema, outputSchema, annotations, and (not sent to clients) fn and arg_info.

Output shaping

Four optional arguments that tidybrreg does not have are added to every tool by the server, all prefixed with a dot so they can never collide with a tidybrreg argument:

• .limit: maximum rows returned (default 200, at most getOption("tidybrregmcp.max_rows", 5000)).

• .offset: rows to skip before returning (default 0).

• .columns: column names to keep, in tidybrreg's English names.

• .format: "records" (default, JSON objects), "csv", or "markdown" for the text rendering of the rows. The structured result always reports the total row count so a caller knows when it saw a slice.

Examples

tools <- mcp_tools()
names(tools)
tools$brreg_entity$inputSchema$properties$registry