A command for adding behaviour-driven development scenarios to an existing TriadJS endpoint or channel. Behaviour-driven development, or BDD, describes expected behaviour as Given, When, and Then steps.

It is for locating an endpoint or channel, setting up test data and requests, and writing scenarios that describe expected outcomes.

It helps test business behaviour in a consistent format while restricting assertions to phrases the project's parser understands.

scenario — Command for Claude Code by justhamade/triadjs

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.

Clone the repo

git clone --depth 1 https://github.com/justhamade/triadjs

Made for: Claude Code.

Or install triadjs, the plugin that ships this one along with the rest of its 10 skills, 8 commands.

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/justhamade/triadjs/scenario/github.svg)](https://agentmods.dev/commands/justhamade/triadjs/scenario)

Your own site

<a href="https://agentmods.dev/commands/justhamade/triadjs/scenario"><img src="https://agentmods.dev/badge/commands/justhamade/triadjs/scenario/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/justhamade/triadjs/scenario"><img src="https://agentmods.dev/badge/commands/justhamade/triadjs/scenario.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 34 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 866 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.

Model	Per session	Once invoked
Fable 5.1	$0.00034	$0.00866
Opus 5.5	$0.00014	$0.00346
Sonnet 5.5	$0.00007	$0.00173
Haiku 4.5	$0.00003	$0.00087

Measured 2mo ago against content hash 2067366ee8bf, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

scenario 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 2mo 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.

plugin/commands/scenario.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Load the triad-behaviors skill — it carries the authoritative assertion phrase table, fixture syntax, and scenario.auto() reference. Do NOT invent phrases — unrecognized strings fail as "Unrecognized assertion".

Add behavior scenarios to an existing endpoint or channel based on the user's description ($ARGUMENTS).

Steps

Locate the target endpoint or channel. If the user gives a name, grep for name: 'thatName'. If they describe the resource, find the matching file in src/endpoints/ or src/channels/.
Understand the business intent first. A scenario name should describe business intent, not mechanics:
- Good: "Duplicate pet names are rejected within the same species"
- Bad: "POST /pets returns 409 when name is taken"
Write the .given() stage — seed fixtures via .setup(async services => { return { foo: ... } }) if the scenario depends on existing state, or use .fixtures({...}) for static values.
Set the request — .body(...), .params(...), .query(...), .headers(...). Use {placeholder} tokens to interpolate fixtures (e.g. .params({ id: '{petId}' })).
Write the .when() narrative — a short string describing the action. This flows to Gherkin but doesn't affect test execution.
Write the .then() and .and() assertions — every phrase must match a row in the phrase table (see triad-behaviors skill):
- response status is <N>
- response body matches <ModelName>
- response body has <path> "<string>" — double quotes, never single
- response body has <path> <number>
- response body has <path> true / false
- response body has length <N>
- response body is an array
- response body is empty (for 204/t.empty() responses)
- response body has code "<CODE>"
For channels, use channel phrases instead:
- <client> receives a <messageType> event
- all clients receive a <messageType> event
- <client> does not receive a <messageType> event
- <client> receives a <messageType> with <field> "<value>"
- connection is rejected with code <N>
Consider adding ...scenario.auto() at the end of the behaviors array if it's not already there — it generates missing-field/boundary/enum/type scenarios from the schema constraints for free.
Run triad test --filter <name> to verify every new scenario parses, seeds correctly, and passes.

Read the full file on GitHub · 58 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.

2mo ago First seen · 58 lines · 34 tokens per session scan A 2067366ee8bf

Subscribe to this mod's changes

scenario is a command published in the GitHub repository justhamade/triadjs (24 stars, last pushed 6mo ago), licensed MIT. It adds 34 tokens to every session and 866 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 2026-08-30.

Testing

scenario next to 6 commands from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
scenariojusthamade/triadjs	Command	24	6mo ago	MIT	A	34	Claude Code
checklistgithub/spec-kit	Command	148k	yesterday	MIT	A	13	Claude Code
clarifygithub/spec-kit	Command	148k	yesterday	MIT	A	27	Claude Code
specifygithub/spec-kit	Command	148k	yesterday	MIT	A	13	Claude Code
analyzegithub/spec-kit	Command	148k	yesterday	MIT	A	26	Claude Code
convergegithub/spec-kit	Command	148k	yesterday	MIT	A	35	Claude Code
implementgithub/spec-kit	Command	148k	yesterday	MIT	A	14	Claude Code