How an agent reaches poly

How an agent reaches poly An architecture diagram generated by Archify. Host adapters · JSON and markdown only · Architecture component Host adapters JSON and markdown only MCP server · poly mcp, over stdio · Check path: No model decides a verdict; never imports poly-io MCP server poly mcp, over stdio Language server · poly lsp, over stdio · Check path: No model decides a verdict; never imports poly-io Language server poly lsp, over stdio poly CLI · one command registry · Check path: No model decides a verdict; never imports poly-io poly CLI one command registry same command registry same command registry host launches poly mcp · spawn host launches poly lsp · spawn Check path: No model decides a verdict; never imports poly-io Legend Frontend Backend Database

The short answer

  • • Through one command registry served three ways: the command line, an MCP server and a language server, plus a workflow server for work orders
  • • A host adapter is a JSON file that launches one of them

Not shown here

  • • The stages of the check and the internals of the runtime
  • • Connected but out of scope: poly-new, Workflow server, Check pipeline, Admission, Feedback commands, Signed records

Doctrine

  • • The core is host-neutral and a host adapter is configuration only: no package names a host or imports a host SDK; an adapter is JSON and markdown that launches poly mcp, poly lsp or poly run --mcp, so a new host adds no code