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 agentmods add skills/juxt/claude-plugins/propagatenpx skills add juxt/claude-plugins --skill propagategit clone --depth 1 https://github.com/juxt/claude-pluginsWhat 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 | $0.00057 | $0.04443 |
| Opus 5 | $0.00028 | $0.02221 |
| Sonnet 5 | $0.00011 | $0.00889 |
| Haiku 4.5 | $0.00006 | $0.00444 |
Grade A, and why
propagate 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.
This is a copy
100% identical to propagate — 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 — 274 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Propagation
This skill generates tests from Allium specifications. Propagation is how plants reproduce from cuttings of the parent: the spec is the parent, the tests are the offspring.
Deterministic tools guarantee completeness (every spec construct maps to a test obligation). You handle the implementation bridge: correlating spec constructs with code, generating tests in the project's conventions.
Interaction modes
This skill runs in two modes. Every instruction below that asks or suggests something to the user follows the mode:
- Interactive — running inline in a conversation. Ask the user directly and wait for the answer.
- Non-interactive — running as the
propagatesubagent (for example inside the Allium loop), where no user is reachable. Report anything that needs a human decision — a spec too coarse to propagate, an ambiguous implementation bridge, uncovered obligations — in your final output and continue with the work that does not depend on it.
Prerequisites
Before propagating tests, you need:
- An Allium spec — the
.alliumfile describing the system's behaviour - A target codebase — the implementation to test
- Test obligations — from
allium plan <spec>(JSON listing every required test) - Domain model — from
allium model <spec>(JSON describing entity shapes, constraints, state machines)
If the CLI tools are not available, derive test obligations manually from the spec using the test-generation taxonomy in references/test-generation.md.
Modes
Surface mode
Generates boundary tests from surface declarations. Use when the user wants to test an API, UI contract or integration boundary.
For each surface in the spec:
- Exposure tests — verify each item in
exposesis accessible to the specified actor, includingforiteration over collections - Provides tests — verify operations appear when their
whenconditions are true and are hidden otherwise, including when the corresponding rule'srequiresclauses are not met - Actor restriction tests — verify the surface is not accessible to other actor types
- Actor identification tests — verify only entities matching the actor's
identified_bypredicate can interact; for actors withwithin, verify interaction is scoped to the declared context - Context scoping tests — verify the surface instance is absent when no entity matches the
contextpredicate - Contract obligation tests — verify
demandsare satisfied by the counterpart,fulfilsare supplied by this surface, including all typed signatures - Guarantee tests — verify
@guaranteeannotations hold across the boundary - Timeout tests — verify referenced temporal rules fire within the surface's context
- Related navigation tests — verify navigation to related surfaces resolves to the correct context entity
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.
- 2d ago First seen · 274 lines · 57 tokens per session scan A 5e2d88808bd9
propagate is a skill published in the GitHub repository juxt/claude-plugins (10 stars, last pushed 4d ago), licensed MIT. It adds 57 tokens to every session and 4,443 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to propagate, differing in 0 lines, and is treated as a copy.
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