start

A command that starts the Cantos system for one Claude Code session. Cantos is a group of specialised assistants coordinated to handle different kinds of work.

In plain words
What is it for?
It is for running the Cantos assistants and their workflows during the current session only.
Why use it?
It lets you use Cantos temporarily without changing or installing anything in your project.

Command

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/ne11nn/cantos-plugin/start
Clone the repo
git clone --depth 1 https://github.com/ne11nn/cantos-plugin
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 370 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 $0.00021 $0.00370
Opus 5 $0.00010 $0.00185
Sonnet 5 $0.00004 $0.00074
Haiku 4.5 $0.00002 $0.00037

Measured 2d ago against content hash 219e32cf86a5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

start 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 2d 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.

commands/start.md · 14 lines

What it actually says

You are now running the Cantos system for THIS session only, from the plugin's bundled copy. Nothing is written to the user's project.

  1. Read ${CLAUDE_PLUGIN_ROOT}/system/CLAUDE.md in full. It is the orchestrator's operating contract. Adopt it as your instructions for the rest of this session, with two adaptations because you are running from the plugin rather than a scaffolded checkout:
    • Skip the First-Run Setup gate. That gate personalizes a writable checkout; this run is ephemeral and read-only. Do not look for or act on the <!-- SETUP-NOT-DONE --> marker, and do not write to context/.
    • All system paths resolve under ${CLAUDE_PLUGIN_ROOT}/system/. Read an assistant's brain at ${CLAUDE_PLUGIN_ROOT}/system/.assistants/<name>/<name>.md, references at ${CLAUDE_PLUGIN_ROOT}/system/references/..., the registry at ${CLAUDE_PLUGIN_ROOT}/system/registry/index.md, and so on. The user's own project files stay untouched unless they ask you to work on them.
  2. Then act on the user's request exactly as Cantos would: assess the domain, morph into the right assistant by reading its brain file from the bundled system, or orchestrate across assistants, then proceed.
  3. If the user wants Cantos to persist and evolve in this project (so /wrap and brain-file updates stick across sessions), tell them to run /cantos:init, which scaffolds the full writable system into the project.

Read the orchestrator file now, then handle the user's request: $ARGUMENTS

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. 2d ago First seen · 14 lines · 21 tokens per session scan A 219e32cf86a5

Subscribe to this mod's changes

start is a command published in the GitHub repository ne11nn/cantos-plugin (1 stars, last pushed 2d ago), licensed MIT. It adds 21 tokens to every session and 370 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.