canary-blackhawk

canary-blackhawk is a skill for Claude Code from bop-clocktower/canary. It costs 90 tokens per session (1,979 once invoked), scanned A, original, MIT.

A static checker for test files that finds dependence on the current time, real delays, or the computer’s local time zone. It recognises common date, time, timer, and formatting calls and ignores tests that already freeze the clock.

In plain words
What is it for?
Use it to inspect test files for wall-clock reads, sleep calls, real timers, local-time formatting, and comparisons involving timezone-free dates.
Why use it?
Tests tied to the real clock can pass most of the time but fail at midnight, during daylight-saving changes, or on leap day. Finding these dependencies early makes test results more predictable.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the canary plugin — 23 skills, 13 commands, 8 agents, 4 hooks shipped together

Good fit Use it to inspect test files for wall-clock reads, sleep calls, real timers, local-time formatting, and comparisons involving timezone-free dates.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bop-clocktower/canary/canary-blackhawk
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 bop-clocktower/canary --skill canary-blackhawk
Clone the repo
git clone --depth 1 https://github.com/bop-clocktower/canary

Made for: Claude Code.

Or install canary, the plugin that ships this one along with the rest of its 23 skills, 13 commands, 8 agents, 4 hooks.

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.

agentmods badge for canary-blackhawk

README.md
[![agentmods](https://agentmods.dev/badge/skills/bop-clocktower/canary/canary-blackhawk/github.svg)](https://agentmods.dev/skills/bop-clocktower/canary/canary-blackhawk)
Your own site
<a href="https://agentmods.dev/skills/bop-clocktower/canary/canary-blackhawk"><img src="https://agentmods.dev/badge/skills/bop-clocktower/canary/canary-blackhawk/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.

agentmods 80×15 button for canary-blackhawk

Your own site · 80×15
<a href="https://agentmods.dev/skills/bop-clocktower/canary/canary-blackhawk"><img src="https://agentmods.dev/badge/skills/bop-clocktower/canary/canary-blackhawk.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,979 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 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 5.1 $0.00090 $0.01979
Opus 5 $0.00045 $0.00989
Sonnet 5 $0.00018 $0.00396
Haiku 4.5 $0.00009 $0.00198

Measured 10d ago against content hash ffa3d6dce359, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

canary-blackhawk 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 10d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/cli.mjs, scripts/rules.mjs, scripts/scanner.mjs, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

agents/skills/claude-code/canary-blackhawk/SKILL.md · 171 lines

How it starts

The opening of the file, as written. The whole thing — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Canary Blackhawk

A test that reads the wall clock is a test with a scheduled outage. It passes every run you watch, then fails at 23:59:59, on the Sunday the clocks move, or on Feb 29. Blackhawk finds those lines before the calendar does.

Tier-0 deterministic analysis: no LLM, no network, no secrets, no dependency on any other skill.

Rules

Rule Severity Fires on
BH001-wall-clock high Date.now(), bare new Date(), moment(), datetime.now() / .today() / .utcnow(), date.today(), time.time(), pd.Timestamp.now()
BH002-real-delay medium time.sleep(n) and setTimeout(fn, n) with a literal n > 0
BH003-local-timezone medium toLocaleString / toLocaleDateString / toLocaleTimeString, strftime('…%Z…') or %z
BH004-naive-datetime-compare low a comparison against datetime(2024, …) or strptime(…) with no tzinfo / timezone.utc / ZoneInfo / pytz on the line

A pinned constructor is never flagged: new Date('2024-01-01T00:00:00Z'), moment('2024-01-01'), and datetime(2024, 1, 1) on its own are all fine.

Framework-conditioned suppression (the important part)

The single biggest failure mode of a temporal linter is firing on tests that already handle time correctly. So when a file installs a frozen clock, every clock-dependent rule (BH001, BH002, BH004) goes quiet for that file. Markers:

vi.useFakeTimers · vi.setSystemTime · jest.useFakeTimers · jest.setSystemTime · sinon.useFakeTimers · MockDate · freeze_time / freezegun · time_machine

Read the full file on GitHub · 171 lines

Files

What ships with it

4 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.

  1. 10d ago First seen · 171 lines · 90 tokens per session scan A ffa3d6dce359

Subscribe to this mod's changes

canary-blackhawk is a skill published in the GitHub repository bop-clocktower/canary (4 stars, last pushed today), licensed MIT. It adds 90 tokens to every session and 1,979 once invoked, about $0.0005 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.