| name | set-up-lead-capture |
| description | Use when adding or hardening a lead, signup, contact, newsletter, or waitlist form on a public page — the form contract (labels, autocomplete, error and success states), a single destination seam (form service / serverless function / own API), layered spam defenses (honeypot, time-trap, escalation to Turnstile), consent at the point of capture, and double opt-in. Framework-agnostic. |
Set Up Lead Capture
A landing page exists to convert; this form is the conversion. The skill wires it with
one destination seam, invisible-first spam defenses, and consent that would survive an
audit.
1. Gate — is this a public page?
Run the gate from ../_shared/page-types.md. Authenticated app forms (settings,
checkout, CRUD) are the other catalogue's job: skills/frontend/set-up-forms
(schema-first, mutation-wired). This skill owns the public, anonymous form.
2. Audit current state
curl -s "$URL" -o /tmp/page.html
grep -oiE "<form[^>]*" /tmp/page.html
grep -ciE "<label" /tmp/page.html
grep -ciE "autocomplete=" /tmp/page.html
grep -ciE "type=\"checkbox\"[^>]*consent|consent[^>]*checkbox" /tmp/page.html
Findings to look for: forms posting directly to a vendor URL scattered per page (no
seam), missing labels, no spam defense, no consent checkbox, success state that dumps
PII into the URL. (As in ../set-up-seo/SKILL.md: the greps are coarse presence checks on double-quoted
attributes — the consent pattern will also match prose mentioning consent and checkbox;
read the page, don't trust the counts.)
3. The form contract
<form method="post" action="/api/leads">
<label for="lead-email">Work email</label>
<input id="lead-email" name="email" type="email" autocomplete="email"
required aria-describedby="lead-email-err">
<p id="lead-email-err" class="field-error" hidden></p>
<div class="hp">
<label for="lead-company2">Leave this field empty</label>
<input id="lead-company2" name="company2" type="text" tabindex="-1" autocomplete="off">
</div>
<input type="hidden" name="form_ts" value="{{render_timestamp}}">
<label class="consent">
<input type="checkbox" name="consent" required>
I'd like to receive the newsletter — see the <a href="/privacy">privacy policy</a>.
</label>
<button type="submit">Get the guide</button>
<p role="status" class="form-feedback"></p>
</form>
.hp { position: absolute; left: -9999px; }
- Minimal fields — each extra field costs conversions and widens PII. Often email alone.
- Real
<label>s; autocomplete for WCAG 1.3.5 input purpose, type="email" for the
right mobile keyboard.
- Error state: inline, per field, announced (
aria-describedby — the field-level
channel). Success state: the role="status" element — the form-level channel —
with visible confirmation that says what happens next ("Check your inbox to
confirm"). One message per channel; don't announce the same thing twice.
4. The destination seam
All forms post to one endpoint/handler; the vendor (CRM, list provider, webhook)
lives behind it, named in one place. Shapes and trade-offs: ./capture-patterns.md.
The handler's contract — whatever implements it:
- Reject silently (normal success response, record dropped) if
company2 is non-empty,
or if form_ts is present and now − form_ts < 3 s. A missing form_ts (JS off on
a static page) degrades gracefully — the honeypot still guards.
- Validate the email server-side; honest inline error for real mistakes.
- Rate-limit by IP.
- Store:
{ email, consent: true, consent_text_version, submitted_at, source_page }.
- Trigger the double-opt-in confirmation; the address is used only after the click.
5. Spam defenses — escalate, invisible first
The honeypot is free, invisible, and static-safe — it goes in always. The time-trap
needs a per-load form_ts (SSR per request, or a one-line inline script setting
Date.now() on load); on a fully static page a build-time timestamp never trips the
check, so treat the time-trap as an upgrade where rendering allows, not a given.
Escalate to Cloudflare Turnstile (managed/invisible mode) only when measured spam
pressure demands; an interactive challenge is the last resort, because every challenge
costs real conversions. Rationale and rejection etiquette: ./capture-patterns.md.
6. Consent + double opt-in
- Checkbox unticked by default; specific text; policy linked. Pre-ticked or bundled
consent isn't consent.
- Record consent (timestamp + text version) with the lead.
- Double opt-in: store unconfirmed → confirmation email → only confirmed addresses enter
the list. Established proof-of-consent practice in the EU. (Engineering guidance, not
legal advice — a regulated project encodes its counsel's rules via
../audit-copy-compliance/SKILL.md.)
7. Verify
- Valid submit → success state, record stored with consent fields, confirmation mail
flow triggers.
- Fill the hidden
company2 field → normal success response, no record.
- Submit within 3 s of load → no record (on per-load
form_ts setups).
- Bad email → inline error names the field.
- View the page with JS disabled: the form is present and labeled (it's in the HTML).
References
- ./capture-patterns.md — destination shapes, spam escalation, silent rejection, consent recording, PII minimization, when to deviate.
- ../_shared/page-types.md — the gate.
- ../../frontend/set-up-forms/SKILL.md — authenticated in-app forms (schema-first, mutation-wired); use that skill there.