A guide to implementing a Language Server Protocol (LSP) server, the software that gives code editors features such as completion, diagnostics, and definition lookup.

It is for implementing LSP servers with autocomplete, error diagnostics, go-to-definition, and hover information.

It provides direction for building editor-language support, including incremental parsing and common editor features.

lsp-design — Skill for Claude Code by revfactory/claude-code-harness

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add revfactory/claude-code-harness --skill lsp-design

Clone the repo

git clone --depth 1 https://github.com/revfactory/claude-code-harness

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/revfactory/claude-code-harness/lsp-design/github.svg)](https://agentmods.dev/skills/revfactory/claude-code-harness/lsp-design)

Your own site

<a href="https://agentmods.dev/skills/revfactory/claude-code-harness/lsp-design"><img src="https://agentmods.dev/badge/skills/revfactory/claude-code-harness/lsp-design/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/revfactory/claude-code-harness/lsp-design"><img src="https://agentmods.dev/badge/skills/revfactory/claude-code-harness/lsp-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 653 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00042	$0.00653
Opus 5.5	$0.00017	$0.00261
Sonnet 5.5	$0.00008	$0.00131
Haiku 4.5	$0.00004	$0.00065

Measured 2mo ago against content hash 6508bf170174, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

lsp-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

experiments/results/case-015/harness/.claude/skills/lsp-design/SKILL.md · 77 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 77 lines · 42 tokens per session scan A 6508bf170174

Subscribe to this mod's changes

lsp-design is a skill published in the GitHub repository revfactory/claude-code-harness (122 stars, last pushed 8mo ago), with no licence file. It adds 42 tokens to every session and 653 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Backend and APIs Languages

lsp-design next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
lsp-designrevfactory/claude-code-harness	Skill	122	8mo ago	none	A	42	Claude Code
agui-dotnet-streaming-chatag-ui-protocol/ag-ui	Skill	17k	yesterday	MIT	A	223	Claude Code
azure-mgmt-apicenter-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	97	Claude Code
azure-communication-chat-javamicrosoft/skills	Skill	3.2k	yesterday	MIT	A	41	Claude Code
minimal-apicodewithmukesh/dotnet-claude-kit	Skill	805	2d ago	MIT	A	101	Claude Code
grpcmanagedcode/dotnet-skills	Skill	508	yesterday	MIT	A	95	Claude Code, Codex
azure-messaging-webpubsubservice-pybenjaminasterA/antigravity-awesome-skills	Skill	461	yesterday	MIT	A	0	Claude Code, Codex