fleet-sim

fleet-sim is a command for Claude Code from datacore-one/datacore. It costs 32 tokens per session (1,086 once invoked), scanned A, original, MIT.

A command that runs a simulated week of a fleet's machine schedules in a sealed Linux container, with injected faults. A fleet is a group of machines managed together; the command compares the latest run with the previous one.

In plain words
What is it for?
Use it for seven-day or shorter simulations, a simulator self-test, and checking whether Docker is available before running.
Why use it?
It helps reveal which schedule scenarios break without changing the live machines. It also makes changes since the last simulation visible.

Command for Claude Code

Written for Claude Code: a Claude Code command (commands/*.md).

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 .datacore/lib/fleet_week_sim.py docker --days N.

Good fit Use it for seven-day or shorter simulations, a simulator self-test, and checking whether Docker is available before running.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/datacore-one/datacore
agentmods
npx agentmods add commands/datacore-one/datacore/fleet-sim

Made for: Claude Code.

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 fleet-sim

README.md
[![agentmods](https://agentmods.dev/badge/commands/datacore-one/datacore/fleet-sim/github.svg)](https://agentmods.dev/commands/datacore-one/datacore/fleet-sim)
Your own site
<a href="https://agentmods.dev/commands/datacore-one/datacore/fleet-sim"><img src="https://agentmods.dev/badge/commands/datacore-one/datacore/fleet-sim/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 fleet-sim

Your own site · 80×15
<a href="https://agentmods.dev/commands/datacore-one/datacore/fleet-sim"><img src="https://agentmods.dev/badge/commands/datacore-one/datacore/fleet-sim.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,086 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 $0.00032 $0.01086
Opus 5.5 $0.00013 $0.00434
Sonnet 5.5 $0.00006 $0.00217
Haiku 4.5 $0.00003 $0.00109

Measured 13d ago against content hash e3cd0900a31e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fleet-sim 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 13d 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.

.datacore/commands/fleet-sim.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/fleet-sim

Run a simulated week of the whole fleet's real schedule in a sealed Linux container on the Mac, and list what breaks — then say what changed since the last run. Issue datacore-one/datacore #222.

Usage

/fleet-sim            # 7 simulated nights (about an hour)
/fleet-sim 2          # 2 nights (quick check after a fix)
/fleet-sim selftest   # the simulator's own tests, in the container (about ten minutes)
/fleet-sim harsh      # 7 nights with the harsh faults on top (F13-F25), compressed to 2-hour steps

harsh adds the faults of HARSH_FAULTS in fleet_week_sim.py to F1-F12, several at once: network throttling and loss (real tc netem on the container's loopback plus the stand-ins), partitions between pairs of machines, a machine down for hours mid-job, repeated reboots, out of memory mid-task (the process, and the whole run), a full disk, clock skew, GitHub unreachable, a rotated credential on one machine, a second writer in the overnight host's checkout, a slow and a rate-limited model. Run it as python3 .datacore/lib/fleet_week_sim.py docker --days 7 --harsh --min-interval 7200 (about two hours). The report opens with what the owner would have had each night: was the delegated task completed, did the briefing and its audio go out.

Not scheduled. The owner decides a cadence later; run it by hand.

Steps

  1. Pre-flight. On the Mac only (it needs Docker). Check docker info answers. If Docker is not running, say so and stop — do not try another machine. The simulator reads committed files (git HEAD) plus five gitignored config files; say if the working tree has uncommitted product changes, because those are NOT in the run.

  2. Run. From the install root, in the background (it takes 50–75 min for 7 nights):

    python3 .datacore/lib/fleet_week_sim.py docker --days N
    

    N is the argument, default 7. For selftest: python3 .datacore/lib/fleet_week_sim.py docker --selftest (no report, no compare).

Read the full file on GitHub · 90 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. 13d ago Changed · +13 lines e3cd0900a31e
  2. 15d ago First seen · 77 lines · 32 tokens per session scan A b02f040d3fc3

Subscribe to this mod's changes

fleet-sim is a command published in the GitHub repository datacore-one/datacore (4 stars, last pushed today), licensed MIT. It adds 32 tokens to every session and 1,086 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-10-01.