flag-landmine

flag-landmine is a skill for Claude Code from CrumbtrailDev/crumbtrail-cli. It costs 71 tokens per session (1,548 once invoked), scanned A, original, MIT.

A troubleshooting guide for differences caused by feature flags or toggles, which are settings that turn application behaviour on or off for selected users or accounts.

In plain words
What is it for?
Use it to compare declared flags and runtime settings when a feature works for one user but not another or an old toggle blocks a newer path.
Why use it?
It helps explain why people on the same build see different behaviour when a flag is missing, outdated, or being used as hidden configuration.

Skill for Claude Code

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

Part of the crumbtrail-skills plugin — 13 skills shipped together

Good fit Use it to compare declared flags and runtime settings when a feature works for one user but not another or an old toggle blocks a newer path.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/crumbtraildev/crumbtrail-cli/flag-landmine
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 CrumbtrailDev/crumbtrail-cli --skill flag-landmine
Clone the repo
git clone --depth 1 https://github.com/CrumbtrailDev/crumbtrail-cli

Made for: Claude Code.

Or install crumbtrail-skills, the plugin that ships this one along with the rest of its 13 skills.

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 flag-landmine

README.md
[![agentmods](https://agentmods.dev/badge/skills/crumbtraildev/crumbtrail-cli/flag-landmine.svg)](https://agentmods.dev/skills/crumbtraildev/crumbtrail-cli/flag-landmine)
Your own site
<a href="https://agentmods.dev/skills/crumbtraildev/crumbtrail-cli/flag-landmine"><img src="https://agentmods.dev/badge/skills/crumbtraildev/crumbtrail-cli/flag-landmine.svg" alt="Measured on agentmods" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,548 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 $0.00071 $0.01548
Opus 5 $0.00036 $0.00774
Sonnet 5 $0.00014 $0.00310
Haiku 4.5 $0.00007 $0.00155

Measured 7d ago against content hash 3d4ac816ebe2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

flag-landmine 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 7d 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.

plugins/crumbtrail-skills/skills/flag-landmine/SKILL.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The flag and toggle landmine

Flags accumulate three jobs at once: configuration, rollout control, and an archive of past workarounds. They are usually free text and usually unvalidated. A toggle nobody has touched for years blocks a new code path, or a flag that was never initialised for some users silently disables a feature for exactly them.

Before running this skill, confirm the recording actually carries a flags map. If it does not, this archetype is invisible to the recording and the first useful action is to make the application declare its flags.

Symptom

Two users on the same build get different behaviour. A feature is off for some accounts and nobody can name the switch. A new path works in one account and short circuits in another. The reporter often frames this as intermittent, because from their side the same action produces different results, but it is stable per user rather than random.

What Crumbtrail can see

The environment snapshot emitted at session start carries the feature flags and the runtime configuration the application declared to the SDK, redacted, and later declarations arrive as deltas on the same channel. getRegressionContext compares two recordings and returns an environment delta naming each flag key, config key, release label and build label that moved between them, so a working session and a broken session can be diffed directly.

Alongside that, the session carries the usual planes: interactions, console, requests and responses, backend spans where the backend integration is installed, and database row changes where the database adapter is installed. Those are what tell you the flag actually changed a code path rather than merely differing.

It does not read your flag provider. Crumbtrail has no connection to a flag service and cannot enumerate the flags that exist, their defaults, their targeting rules, or their history. Only the values the application chose to declare are present, and only from the moment it declared them. If the application never declares its environment, the flags section is absent and no query in this skill will produce anything.

Read the full file on GitHub · 149 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. 7d ago First seen · 149 lines · 71 tokens per session scan A 3d4ac816ebe2

Subscribe to this mod's changes

flag-landmine is a skill published in the GitHub repository CrumbtrailDev/crumbtrail-cli (0 stars, last pushed today), licensed MIT. It adds 71 tokens to every session and 1,548 once invoked, about $0.0004 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.

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