context-lifecycle

A code-review skill for finding mistakes in the lifetime of Go contexts used by asynchronous work. A context carries cancellation and timing information, so using a request’s context for longer-lived work can stop that work too early.

In plain words
What is it for?
Use it when reviewing goroutines, timers, callbacks, actor messages, startup work, notification subscriptions, or other asynchronous code that may outlive its caller.
Why use it?
It helps detect background tasks that silently end when an RPC, test, or request finishes, even though they were meant to continue.

Skill for Claude CodeCodex

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 skills/lightninglabs/wavelength/context-lifecycle
Any agent
npx skills add lightninglabs/wavelength --skill context-lifecycle
Clone the repo
git clone --depth 1 https://github.com/lightninglabs/wavelength

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,585 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 $0.00053 $0.01585
Opus 5 $0.00026 $0.00792
Sonnet 5 $0.00011 $0.00317
Haiku 4.5 $0.00005 $0.00159

Measured 2d ago against content hash 803d074cda1e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

context-lifecycle 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/skills/context-lifecycle/SKILL.md · 231 lines

How it starts

The opening of the file, as written. The whole thing — 231 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Context Lifecycle Review

Use this skill to catch async work that accidentally captures a short-lived caller context.

The failure mode is subtle: ctx is usually the nearest variable, so a goroutine, timer, callback, or actor handoff may inherit an RPC/test/request context even though the work must continue after that caller returns. When the caller exits, the context is cancelled and the background work can silently stop too early.

Core Question

For every asynchronous handoff, ask:

Who owns this work, and when should it stop?

The answer determines which context is correct.

Start with targeted searches instead of reading whole packages:

rg -n 'go func|AfterFunc|time\.AfterFunc|context\.AfterFunc' \
  --glob '*.go' [path]

rg -n 'Done\(|WithCancel\(|WithTimeout\(|WithDeadline\(' \
  --glob '*.go' [path]

rg -n '\.Tell\(|\.Ask\(|Register|Subscribe' \
  --glob '*.go' [path]

Then inspect each hit in context.

Classify The Owner

Classify each async handoff before suggesting a fix.

Caller-Owned Work

The caller waits for the goroutine before returning, or the goroutine only performs request-scoped work.

Using the caller context is usually correct.

Examples:

  • a goroutine joined by WaitGroup.Wait before return
  • a worker that sends one result and the function waits on that result
  • a helper that should abort when the RPC deadline expires

Component-Owned Work

The work is started by a caller but owned by a daemon, wallet, actor, or service after startup.

Do not capture the RPC/request context. Use a component root context, a registration-owned context, or an explicit context with its own cancel path.

Examples:

  • wallet sync loops started by UnlockWallet
  • daemon background workers started from an RPC
  • actor goroutines started during actor construction
  • server connection runtimes started by daemon setup

Registration-Owned Work

The work forwards notifications until an explicit returned Cancel, Stop, or subscription teardown is invoked.

Read the full file on GitHub · 231 lines

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 · 231 lines · 53 tokens per session scan A 803d074cda1e

Subscribe to this mod's changes

context-lifecycle is a skill published in the GitHub repository lightninglabs/wavelength (44 stars, last pushed 3d ago), licensed MIT. It adds 53 tokens to every session and 1,585 once invoked, about $0.0003 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 2026-08-30.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

agent-host-chat-contributions

Build and review cross-cutting agent-host chat behavior through lifecycle contributions. Use when adding turn lifecycle side effects, prompt or context injection, restored-history transformation, protocol-action observation, or when reviewing changes that add code to AgentSideEffects or AgentService.

microsoft/vscode · 56 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens