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.
npx skills add JustineDevs/premortem --skill dependency-confusiongit clone --depth 1 https://github.com/JustineDevs/premortemWrote 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.
[](https://agentmods.dev/skills/justinedevs/premortem/dependency-confusion)<a href="https://agentmods.dev/skills/justinedevs/premortem/dependency-confusion"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/dependency-confusion/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.
<a href="https://agentmods.dev/skills/justinedevs/premortem/dependency-confusion"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/dependency-confusion.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00056 | $0.02356 |
| Opus 5 | $0.00028 | $0.01178 |
| Sonnet 5 | $0.00011 | $0.00471 |
| Haiku 4.5 | $0.00006 | $0.00236 |
Grade A, and why
dependency-confusion scanned grade A with 1 finding 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 9d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
# curl "https://search.maven.org/solrsearch/select?q=g:com.example+AND+a:internal-lib&rows=1&wt=json" This is a copy
100% identical to dependency-confusion — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Dependency Confusion — Supply Chain Attack Playbook
AI LOAD INSTRUCTION: Expert dependency-confusion methodology. Covers how private package names leak, how public registries can win version resolution, ecosystem-specific pitfalls (npm scopes, pip extra indexes, Maven repo order), recon commands, non-destructive PoC patterns (callbacks, not data exfil), and defensive controls. Pair with supply-chain recon workflows when manifests or CI caches are in scope. Only use on systems and programs you are authorized to test.
0. QUICK START
What to look for first
- Manifests listing package names that look internal (short unscoped names, org-specific tokens, product codenames) without a hard-private registry lock.
- Evidence the same name might exist—or be squattable—on a public registry with a higher semver than the private feed publishes.
- Lockfiles missing, stale, or not enforced in CI so
install/buildcan drift toward public metadata.
Fast mental model: If the resolver can see both private and public indexes, and version ranges allow it, the “newest” matching version may be the attacker’s.
Routing note: if the task comes from supply-chain, repository exposure, or CI-build recon, first use recon-for-sec to list internal package names and possible public-registry collisions.
1. CORE CONCEPT
- Private packages: An organization ships libraries only on an internal registry (or under conventions that imply “ours”), e.g. a scoped name like
@org-scope/internal-utilsor an unscoped name such asacme-billing-sdk. - Attacker squats the name: The same package name is published on a public registry (npmjs, PyPI, RubyGems, etc.).
- Resolver preference: Many setups resolve highest matching version across all configured indexes (or merge metadata), so a public
9.9.9can beat a private1.2.3if ranges allow. - Execution: Package managers run lifecycle scripts (npm
preinstall/postinstall, setuptools entry points, etc.) → attacker code runs on developer laptops, CI, or production image builds.
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.
- 9d ago First seen · 179 lines · 56 tokens per session scan A 8da1209f3125
dependency-confusion is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 56 tokens to every session and 2,356 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to dependency-confusion, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
awesome-azd-template-submit
Submit an azd template to the awesome-azd gallery. Use when asked to submit, add, or contribute a template to awesome-azd. Requires only a GitHub repository URL — all metadata (title, description, languages, frameworks, Azure services, IaC) is auto-detected by the submission pipeline.
bitbottle
Reference for the bitbottle CLI — a gh-style tool for Bitbucket Server/DC and Cloud. Load when the user asks about bitbottle commands, auth setup, PRs, repos, branches, tags, commits, pipelines, or why a command failed. Load even if the user just says "bitbottle", mentions "Bitbucket", or pastes a bitbottle error…
azure-cli
Operational skill for agents to manage Microsoft Azure via az CLI - subscriptions, resource groups, AKS, App Service, Key Vault, and RBAC hygiene.
azure-cli
A command-line tool for managing Microsoft Azure, Microsoft's cloud platform, from a terminal. It covers account sign-in, subscriptions, resource groups, virtual machines, and other cloud resources.
extract-api
This skill should be used when the user asks to "extract API from", "import API from", "add commands from this repo", "register API from docs", "convert docs to CLI commands", "import Postman collection", or provides a GitHub repository URL, a documentation site URL, a Postman collection file/URL, or a local API…
sidekick
ALWAYS run sdkck search FIRST before using ANY tool, MCP server, Bash command, or external API. sdkck is the canonical command surface for Jira, Sentry, MySQL, Postgres, Supabase, Bitbucket, Confluence, and imported OpenAPI/Postman specs. Trigger on every task involving external systems, APIs, databases, tickets…