just-works: Skill for Claude Code

.claude/skills/synthetic-user-research/SKILL.md

synthetic-user-research is a skill for Claude Code from Dynokostya/just-works. It costs 89 tokens per session (1,232 once invoked), scanned A, original, Apache-2.0.

A research method that uses AI-created personas to test whether people can understand copy, onboarding, explanations, or surveys. It also checks whether synthetic research is suitable and labels its findings as synthetic.

In plain words
What is it for?
Use it for early checks of messages, user flows, survey questions, and research plans, followed by a plan for testing important findings with real people.
Why use it?
It can find confusing wording and flawed questions before recruiting real participants. It avoids treating AI personas as evidence of what people will buy, feel, or do.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is Dynokostya/just-works's own configuration. It tells Claude Code how to work on just-works itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything just-works configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Dynokostya/just-works. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/Dynokostya/just-works/main/.claude/skills/synthetic-user-research/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/Dynokostya/just-works

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 synthetic-user-research

README.md
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Your own site
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agentmods 80×15 button for synthetic-user-research

Your own site · 80×15
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Per session 89 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,232 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 $0.00089 $0.01232
Opus 5.5 $0.00036 $0.00493
Sonnet 5.5 $0.00018 $0.00246
Haiku 4.5 $0.00009 $0.00123

Measured 17d ago against content hash 0841cf3fb2f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

synthetic-user-research 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 17d 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.

.claude/skills/synthetic-user-research/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Synthetic User Research

AI personas are useful in a narrow lane of questions and misleading outside it. A synthetic panel can catch comprehension failures, confusing flows and survey defects before real participants are spent on them. It cannot tell you what people will pay for, feel or do. This skill checks that the question is in the lane, then runs the method. Sometimes the result is "no, here is the human study to run instead".

The lane (checked before anything runs)

Synthetic methods can probe questions whose answer lives in the artifact, not in people's feelings:

  • Comprehension: is this copy, onboarding or explanation understandable, and where does a reader stumble?
  • Instrument defects: leading questions, double-barrelled items and missing answer options, found before a survey is fielded.
  • Information architecture: can someone with a goal find the thing, and where does the navigation mislead?
  • Message differentiation: do these three positionings read as different?
  • Edge cases: which user situations did the design forget? Personas serve as brainstorming here, not as evidence.

Synthetic methods cannot establish the following, so refuse these questions and say why:

  • Willingness to pay, purchase intent or price sensitivity. Models have no budget and agree too readily.
  • Emotional response, delight or trust. A model's simulated feeling carries no information.
  • Unknown needs. Personas recombine known data, and discovery is about what is not yet known.
  • Behavior. What people say they would do is already unreliable, and a model's guess at it is worse.
  • Validation of a launch or investment decision. Synthetic output is not evidence of demand.

Required inputs

Ask for these if they are not provided:

  • The research question. Run the lane check first and give the verdict before choosing a method.
  • Real data to ground the personas: interview notes, support tickets, reviews, analytics segments. With no real data there is no panel, because ungrounded personas only repeat the model's stereotypes.
  • The artifact under test: the copy, flow, survey or navigation.
  • The decision this feeds and its stakes. Higher stakes narrow the lane.

Read the full file on GitHub · 74 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. 17d ago Changed · -7 lines · -35 tokens per session 0841cf3fb2f4
  2. 1mo ago First seen · 81 lines · 124 tokens per session scan A 56fcb97736f3

Subscribe to this mod's changes

synthetic-user-research is a skill published in the GitHub repository Dynokostya/just-works (14 stars, last pushed 10d ago), licensed Apache-2.0. It adds 89 tokens to every session and 1,232 once invoked, about $0.0004 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 2026-09-20.

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