coop

A command that finds games owned by two Steam players and compares their playtime. It uses Steam identifiers or profile names to look up each library.

In plain words
What is it for?
Use it to list shared games, rank them by combined playtime, and provide store links for the best matches.
Why use it?
It removes the need to compare two large game collections manually when choosing something both players can play.

Command 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 commands/stealthsrc/steam-mcp/coop
Clone the repo
git clone --depth 1 https://github.com/stealthsrc/steam-mcp

Made for: Claude Code.

Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 306 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 $0.00018 $0.00306
Opus 5 $0.00009 $0.00153
Sonnet 5 $0.00004 $0.00061
Haiku 4.5 $0.00002 $0.00031

Measured yesterday against content hash 76b48b8b2b04, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

coop 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 yesterday.

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/commands/steam/coop.md · 33 lines

What it actually says

Find common games between: $ARGUMENTS

The argument contains two Steam identifiers separated by a space (SteamID64 or vanity URLs). Example: stealthylabs gabelogannewell or gabelogannewell robinwalker

Do the following in parallel:

  1. steam_get_owned_games for the first player (limit: 500, include_appinfo: true, sort_by: "playtime")
  2. steam_get_owned_games for the second player (limit: 500, include_appinfo: true, sort_by: "playtime")

Then compute the intersection: games where the AppID exists in both libraries.

Present the results:

Games in common - {Player1} & {Player2}

{X} games in common out of {Y} and {Z} total games.

Show a table of shared games sorted by combined playtime (player1 + player2):

Game AppID {Player1} playtime {Player2} playtime Combined

Limit to the top 20 results.

After the table, add store links for the top 5:

If one or both libraries are private, explain which player's library could not be accessed.

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. yesterday First seen · 33 lines · 18 tokens per session scan A 76b48b8b2b04

Subscribe to this mod's changes

coop is a command published in the GitHub repository stealthsrc/steam-mcp (1 stars, last pushed 8d ago), licensed MIT. It adds 18 tokens to every session and 306 once invoked, about $0.0001 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.