propagate

A tool for creating software tests from Allium specifications, which are structured descriptions of how software should behave. It can also compare the required test obligations with the tests that exist.

In plain words
What is it for?
It generates test files, including property-based and state-machine tests, and reports covered and uncovered parts of a specification.
Why use it?
It reduces the chance that written requirements are left untested and identifies obligations that the current tests do not cover.

Agent

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 agents/juxt/allium/propagate
Clone the repo
git clone --depth 1 https://github.com/juxt/allium
Per session 57 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,604 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 $0.00057 $0.04604
Opus 5 $0.00028 $0.02302
Sonnet 5 $0.00011 $0.00921
Haiku 4.5 $0.00006 $0.00460

Measured yesterday against content hash 54865d74c73e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • propagate — 100% identical, 0 lines differ
.github/agents/propagate.agent.md · 278 lines

How it starts

The opening of the file, as written. The whole thing — 278 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Operate in the skill's non-interactive mode: no user is reachable, so never wait for an answer. Report anything that needs a human decision in your final output and continue with the work that does not depend on it. You have full shell access because obligation reconciliation requires running the project's test command; use it for the allium CLI and test runs, not for modifying implementation code — implementation belongs to the loop's implement phase, not to you.

Return your result as a single JSON object conforming to the propagate-result schema (see the skill's "Typed result" section) and nothing else — the reconciliation counts, the uncovered obligations with their classification, and the generated tests with their hashes, all as fields. Not the file contents, and no prose around the object.

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 propagate subagent (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:

  1. An Allium spec — the .allium file describing the system's behaviour
  2. A target codebase — the implementation to test
  3. Test obligations — from allium plan <spec> (JSON listing every required test)
  4. Domain model — from allium model <spec> (JSON describing entity shapes, constraints, state machines)

Read the full file on GitHub · 278 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. yesterday First seen · 278 lines · 57 tokens per session scan A 54865d74c73e

Subscribe to this mod's changes

propagate is an agent published in the GitHub repository juxt/allium (477 stars, last pushed 5d ago), licensed MIT. It adds 57 tokens to every session and 4,604 once invoked, about $0.0003 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 2026-08-30.