DiagKit — small honest diagnostics + the templates that go with them

DiagKit is the diagnostics-and-templates half of Leefan Reports. Six pages today: three browser-only checkers (thinness, GA4 click-event firing, affiliate compliance — the compliance one is held to v1.1 until legal review passes); three templates (a small Notion PM workspace, a card schema + 5 starter cards, a decision-log template with worked examples).

Each diagnostic runs locally in your browser. You paste an input; the page tells you what it sees. No sign-up. No email gate. No data leaves your tab.

1. The contract for everything in DiagKit

Client-only. The page runs in your browser. Your pasted input never leaves the tab. We do not run a backend. We do not log your input. There is no analytics event on the snippet you pasted — only on the fact that the page was visited.
Heuristic, not verdict. Every tool returns a signal, not an answer. A diagnostic that returns “this page is thin” is telling you that one specific marker set is satisfied; it is not a content-quality oracle. Each tool’s page declares the markers it checks and does not check.
No email gate to run. The tool is on the page. You do not sign up; you do not subscribe; you do not “request access”.

If you find a DiagKit tool that violates any of these three lines, that is a defect — email contact@leefan.co.jp with the correction label.

2. The six pages, grouped

Diagnostics (browser-only checkers)

#	Page	What you paste	What it returns	Trust tier
1	D01 — Content thinness self-check	A page URL or raw HTML body.	Marker-by-marker breakdown + aggregate “thin / mixed / not thin” + “what this does NOT check” panel.	Heuristic — flagged thinness ≠ Google penalty.
2	*D02 — GA4 `click_` event firing checker**	A GTM tag JSON or a raw `dataLayer.push` snippet.	8-check pass/fail list with the specific failure called out and the fix described.	Static-pattern analysis — does not confirm the tag fires live. Use GTM Preview + GA4 DebugView for that.
3	D04 — Affiliate page compliance check HELD to v1.1	A page URL or raw HTML body.	12-marker scan for JP-domestic compliance signals (景品表示法, ステマ規制, インボイス制度 obligations, 印紙税 applicability) plus an explicit “this is heuristic, not legal advice” panel.	Held to v1.1. Ships after legal review. The page itself renders a “coming after legal review” landing here; the full scanner body is not exposed.

Templates (downloadable shapes you can adapt)

#	Page	What you get	What you cannot expect
4	P01 — Notion pSEO PM workspace	A 4-database Notion schema (Cards / Pages / Decisions / Regressions) with a duplicatable markdown export.	A 14-database “ultimate” workspace. Four is the smallest shape that survives a real operation.
5	P03 — Card schema + 5 starter cards	The card JSON schema + 5 runnable starter cards (thinness review, page-uniqueness audit, GA4 dimension registration, regression-DB intake, rollback-verify).	A finished pipeline. The starter pack assumes you have read OpsLab A1.
6	P07 — Decision log template + 3 worked examples	A copy-pastable decision-log shape + three real worked examples (one is a reversed decision — the most useful kind).	A Slack-style conversation log.

3. Which tool to start with, by symptom

“My GA4 events are not showing up in reports.” → Start at D02.
“I have 200 programmatic pages and Google is not indexing many of them.” → Start at D01.
“I just added an affiliate link to a page and I’m not sure my disclosure is enough.” → Start at D04 when it ships in v1.1. Until then, this hub does not point you at a substitute we cannot stand behind.
“I want to start running cards but I do not know what a card schema looks like.” → Start at P03.
“My team’s decisions never get written down.” → Start at P07.
“I want to set up a PM workspace from scratch.” → Start at P01.

4. Why DiagKit is six pages and not sixty

Every page has a load-bearing artifact: a working browser-only tool, a schema, or a template with worked examples.
We do not ship a diagnostic until we have stared at the bug class.
The cost of a wrong diagnostic is higher than the cost of a missing diagnostic. A reader who pastes a snippet and gets a false-pass walks away thinking the problem is elsewhere. We hold pages back (D04) and keep the heuristic-not-verdict disclaimer above the fold (every page) for this reason.

5. Where these pages plug into the rest of the site

From DiagKit → OpsLab: P03 is the downloadable companion to the OpsLab A1–A5 cluster. P01 is the database shape of OpsLab A5’s audit-log idea.
From DiagKit → ToolLab: D04’s affiliate-compliance check assumes you have already chosen a payment platform; if you have not, M01 (Gumroad vs BOOTH vs Stripe) is the upstream choice.
From DiagKit → /about: every diagnostic’s privacy disclosure is a single line; the practice-wide posture is on /about.

6. The “what’s not here yet” list

As of 2026-05:

D04 — held to v1.1 until counsel passes on the heuristic markers, specifically Japanese premium-representation and stealth-marketing disclosure markers.
D03 — cross-page uniqueness across N URLs. Planned.
D08 — title / lead / heading structure check. Planned.
P05 — per-page uniqueness contract. Planned.
P09 — ASP affiliate readiness checklist. Planned.
P14 — sub-agent stop-contract pattern. Planned (cluster B on OpsLab).
A consent-mode-aware variant of D02 — only if demand justifies it.

7. How to read DiagKit if you are…

A solo pSEO operator with one specific bug right now. Use §3.
A team lead evaluating whether to adopt the methodology. Read §1 (the contract) and §4 (why the section is small). Then click into D02 and run it on a real snippet.
A JP-domestic operator with an affiliate-page compliance question. D04 is held to v1.1. The honest recommendation is to consult counsel directly until D04 is unblocked.
Here because someone shared a single tool link. Use the tool; ignore the hub.

8. The privacy / data-handling disclosure

The page’s JavaScript runs in your browser. The snippet you paste stays in your browser tab; it is not POSTed to any server we control.
We use GA4 page-view events on the Leefan Reports site (standard analytics); we do not instrument any DiagKit tool’s input field with analytics.
There is no cookie set by any DiagKit diagnostic.
We do not embed third-party trackers on DiagKit pages.

If a future DiagKit diagnostic requires a server-side step, the page will say so in plain language above the input field, name the data sent, name the destination, and name the retention.