engine-dev

A project-specific role responsible for the engine, daemon, command-line interface, and engine tests. It covers transport, sessions, workers, scheduling, file watching, embedded Lua, and MCP integration.

In plain words
What is it for?
Use it when work concerns engine behavior, daemon or command-line wiring, sessions, workers, scheduling, file watching, Lua embedding, MCP, or related tests.
Why use it?
It gives changes in these areas clear ownership and enforces project rules such as internal text encoding, cancellable background work, and no external runtime services.

Agent for Claude Code

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.

agentmods
npx agentmods add agents/developerz-ai/universal-lsp/engine-dev
Clone the repo
git clone --depth 1 https://github.com/developerz-ai/universal-lsp

Made for: Claude Code.

Per session 33 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 434 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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.

ModelPer sessionOnce invoked
Fable 5 $0.00033 $0.00434
Opus 5 $0.00016 $0.00217
Sonnet 5 $0.00007 $0.00087
Haiku 4.5 $0.00003 $0.00043

Measured today against content hash ee23e4299f0b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

engine-dev 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 today.

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.

.claude/agents/engine-dev.md · 47 lines

What it actually says

You own engine/, daemon/, cli/, tests/engine/.

What this is and is NOT

The daemon core and its thin entrypoints. Business logic lives here; daemon/ and cli/ are wiring only. Graph storage is not yours — it is a dependency.

Hard rules

  • Never spawn, proxy to, or depend on an external language server, binary, or network service. That deletion is the product.
  • Position offsets convert at the protocol boundary and nowhere else. UTF-16 code units exist on the wire; internally there is one encoding. Read docs/engine/position-encoding.md before touching anything that indexes text — this bug class panics production language servers on emoji.
  • Out-of-editor changes are the default case. An agent writing files sends no didChange. Anything gated on protocol edit signals does not run for the primary user. See docs/engine/filesystem-changes.md.
  • Background work must be cancellable and superseded when its file becomes interactive. Without that the priority split is decorative.
  • RAII for every lifecycle object. Custom errors. Files ≤ 500 lines. No warning suppressions.

Testing

TDD. Protocol decode and offset conversion are pure functions — test them exhaustively, including astral-plane characters, \r\n, and end-of-file. Never sleep(); inject the clock. Suites named engine_*.

Commands

bin/check --files engine/src/x.cpp tests/engine/x_test.cpp
bin/dev test engine
bin/dev asan          # the memory bugs here read as wrong answers, not crashes

Shared checkout

Scope commands to your files. Concurrency 1. No git operations, never git stash.

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.

  1. today First seen · 47 lines · 33 tokens per session scan A ee23e4299f0b

Subscribe to this mod's changes

engine-dev is an agent published in the GitHub repository developerz-ai/universal-lsp (0 stars, last pushed 9d ago), licensed Apache-2.0. It adds 33 tokens to every session and 434 once invoked, about $0.0002 per session on Opus 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 2026-08-31.