SolidLSP

src/solidlsp is the library under everything: one interface over the Language Server Protocol, wrapped around some sixty real language servers. It ships in the wheel alongside serena and interprompt, and it is deliberately absent from the generated Code Reference — which makes this page its front door.

The shape of it

One abstract core, many small adapters:

• SolidLanguageServer (ls.py) — the abstract base every language-server adapter extends: lifecycle, requests, file buffers, symbol retrieval. This is the class you inherit from when adding a language.

• language_servers/ — 74 adapters, one per server, and almost all of them small: pick a dependency-provider base, declare how to launch, add the server-specific initialization.

• dependency_provider.py — the LanguageServerDependencyProvider family: how a server gets onto the machine (uvx, a command, a single binary, or bespoke setup) and how every download is checksum-verified against resources/downloaded_dependency_hashes.json.

• ls_config.py — the registry: LanguageServerId (every supported server), FilenameMatcher (which files belong to which language), LanguageServerConfig.

• initialize_params.py — the InitializeParamsBuilder, which owns the common LSP initialization keys so an adapter states only what is specific to its server.

• lsp_protocol_handler/, ls_process.py, ls_request.py, ls_types.py — the wire: process management, JSON-RPC, protocol types.

How Serena uses it

The serena package reaches SolidLSP through LanguageServerManager (src/serena/ls_manager.py), which starts, holds and restarts servers per project; the symbol tools sit on top. The separation is deliberate: SolidLSP knows nothing about agents or tools — it answers questions about code, over LSP, and that is all.

Working in it

Two kinds of work happen here, and they carry different etiquette:

Adding a Language Server

The walk-right-in contribution — the path is mapped, and adapters are deliberately shaped so that most of yours is already written.

Changing the Core

Lifecycle, buffers, initialization, process handling — this work deserves more care. The core holds principles that are easy to bend without noticing: files are never left open, a missing server fails fast rather than degrading quietly, cleanup must never orphan a process. The record shows that correct-looking symptom fixes which bend one of these get reworked by the maintainers even when the diagnosis was right — the FAQ explains that pattern — so for core changes, an issue first goes a long way.