I was going to open a feature request on Mempool.Space's github for a built-in MPC endpoint. Then I imagined the issue being closed because it'd make more sense as a dependent microservice. Then I went looking for an existing MCP server and found this.
I haven't used it yet or even looked at the code much, but it at least intends to do what I want: talk to bitcoin (or talk to an LLM that effectively has access to the timechain and mempool).