Whether an MCP tool call is running

Returns TRUE while a tool runs for an MCP request, and FALSE otherwise, for example when the in-dashboard chat calls the same tool. While it is TRUE, the environment variable SHIDASHI_USING_MCP is set to "TRUE", so code that cannot call this function, such as skill scripts running in their own process, can check the variable instead.

Usage

mcp_call_active(v)

Arguments

v

optional logical; when given, turns the state on (TRUE) or off (anything else), and sets or removes SHIDASHI_USING_MCP to match. App code normally only reads the state.

Value

TRUE or FALSE: the state after any change.

Details

The dashboard's MCP handler turns the state on before each tool call and off when the call returns, also when the tool fails. A tool that returns a promise returns before the promise settles, so code that runs once it settles sees FALSE.

Examples

# Outside of an MCP tool call
mcp_call_active()
#> [1] FALSE
Sys.getenv("SHIDASHI_USING_MCP")
#> [1] ""

# In a tool: print less when an agent calls it over MCP
summarize_values <- function(x) {
  if (!mcp_call_active()) {
    message("Summarizing ", length(x), " values")
  }
  summary(x)
}
summarize_values(1:10)
#> Summarizing 10 values
#>    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#>    1.00    3.25    5.50    5.50    7.75   10.00