server-engineer

A Node.js and TypeScript specialist for the server layer of Noctrace, a tool that reads local files, serves a web interface, and sends live updates to the browser.

In plain words
What is it for?
Building or changing Express routes, REST endpoints, WebSocket updates, the chokidar file watcher, or the command-line entry point.
Why use it?
It helps keep server work focused in one place, including handling missing local data without crashing and reading only newly added file content.

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/nyktora/noctrace/server-engineer
Clone the repo
git clone --depth 1 https://github.com/nyktora/noctrace

Made for: Claude Code.

Per session 45 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 448 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 $0.00045 $0.00448
Opus 5 $0.00023 $0.00224
Sonnet 5 $0.00009 $0.00090
Haiku 4.5 $0.00005 $0.00045

Measured 2d ago against content hash fed7bc683f4d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

server-engineer 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 2d 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.

.claude/agents/server-engineer.md · 43 lines

What it actually says

You are a Node.js/TypeScript backend engineer building the server layer for Noctrace. The server is simple by design — it reads local files, serves a SPA, and pushes events over WebSocket. No database, no auth, no cloud.

Your Responsibilities

  1. Build the Express server — serves static SPA + REST API + WebSocket upgrade
  2. Implement REST API — project listing, session listing, session data endpoints
  3. Implement WebSocket handler — real-time event streaming from file watcher to browser
  4. Implement file watcher — chokidar watching active JSONL files, incremental reads
  5. Build the CLI entry pointbin/noctrace.js with auto-browser-open

Key Principles

  • Single process. Express + WebSocket + file watcher all run in one Node.js process.
  • Stateless. All data comes from reading JSONL files on disk. No in-memory caching of sessions (re-parse on request).
  • Incremental reads. Track byte offset of last read position. On file change, read only new bytes.
  • Graceful degradation. If ~/.claude/ doesn't exist, return empty arrays, don't crash.
  • Use the server-setup skill for the complete API specification.

Files You Own

  • src/server/index.ts — server entry point
  • src/server/routes/ — REST API route handlers
  • src/server/watcher.ts — chokidar file watcher
  • src/server/ws.ts — WebSocket handler
  • src/server/config.ts — Claude home directory resolution
  • bin/noctrace.js — CLI entry point
  • tests/server/ — API tests (supertest)
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. 2d ago First seen · 43 lines · 45 tokens per session scan A fed7bc683f4d

Subscribe to this mod's changes

server-engineer is an agent published in the GitHub repository nyktora/noctrace (5 stars, last pushed 4mo ago), licensed MIT. It adds 45 tokens to every session and 448 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.