adr-sml/docs/05-backend-spec.md

05 — Intake, booking, and data handling

Authority: AGENTS.md §3 D10 — rebuilt intake form plus calendar booking. Existing infrastructure is authoritative in AGENTS.md §7. How it was built is recorded in docs/reference/AWS-Hosting-Guide.md Parts 8–10 — a historical record with a do-not-execute banner, superseded by §7 wherever they disagree. Read that guide before changing anything; the resources already exist and were built by hand in the console.

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What exists today

API Gateway (HTTP API) → Lambda → DynamoDB, with SES for notification email and a verified sender on smlcompany.ca. [verified 2026-08-26 — AGENTS.md §7]

The shape is right. This is a hardening and rework pass, not a replacement.

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Build step 8, as actually built — 2026-08-31

What is in the repository: /contact/ with the intake form, two POST-redirect-GET landing pages, and backend/intake/handler.mjs + backend/intake/fields.mjs — the handler that replaces the hand-built adr-intake-handler §7 records.

What is NOT done, and the form does not work until it is. Nothing on this project deploys before cutover (D11), so: the handler is not deployed, and the CloudFront /api/* behaviour the form posts to does not exist. Both are on docs/06's cutover checklist. /contact/ publishes the email address as well as the form for exactly this reason.

The form is a plain HTML POST, and it answers 303

The site ships zero JavaScript (§7 — none, not "minimal"), so the form is a <form method="post"> and the handler replies 303 See Other to a page on the site. That buys three things with no script anywhere: it works with JavaScript disabled, which is the failure this whole project exists to fix; the visitor never sees a raw JSON body rendered as a page; and a refresh cannot resubmit, because the browser lands on a GET.

Two pages exist for the two outcomes — /contact/received/ and /contact/could-not-send/. Both are noindex and both are excluded from the sitemap in astro.config.mjs. The failure page names no field, because the handler deliberately does not return the error list (an enumeration of the validation rules is a gift to whoever is probing them) and because a static page cannot read ?error= without script.

It posts to /api/intake, not to the execute-api hostname

Same-origin, with a CloudFront behaviour routing /api/* to the HTTP API origin §7 records. Four consequences, and the fourth is the one that matters day to day: form-action 'self' alone satisfies the CSP below; there is no cross-origin POST to reason about; the endpoint id stays out of the HTML and out of the repo; and submitting the form from astro dev does nothing, because there is no /api/ route locally. Under the alternative, clicking Submit on a laptop would write a real DynamoDB record and send two real emails.

⚠️ Three deviations from this spec, each deliberate

1. The 3-second timestamp check is NOT implemented. It cannot be, and implementing it would produce a control that does nothing. The check needs to know when the form was served to that visitor; /contact/ is a static file cached at the CloudFront edge, so a build-time timestamp is the same value for every visitor and is hours or days old. now − served is therefore always large, and the check passes for a bot exactly as it passes for a human. A per-visitor token needs a dynamic origin or client-side script, and the site has neither by design.

A control that exists on paper and not in fact is worse than a stated gap — that is what AGENTS.md Q22 and the Lighthouse row both cost. So it is omitted and said out loud, and the load is carried by the honeypot, the Origin check, the API Gateway rate limit and server-side validation.

2. CORS is not what protects the form, and the Origin check is. A form POST is a top-level navigation: it is exempt from CORS preflight, so an Access-Control-Allow-Origin setting cannot stop another site posting a form here. The handler compares Origin (falling back to Referer, which Firefox sends where it omits Origin) against the site origin and refuses anything else. The CORS restriction in this spec is still right — it governs scripted calls to the endpoint — but it is a different control and was being relied on for this one.

3. There is no mailto: fallback, because there is nothing to fall back FROM. This spec's definition of done asks that the form "degrades to a mailto: fallback with JavaScript disabled". The form never used script, so it does not degrade. The email address is published on /contact/ regardless, and the failure page routes to it.

Two field tables, cross-checked

src/data/intake.ts builds the form. backend/intake/fields.mjs is what the handler validates against. The duplication is architectural, because this spec's own rule is that the Lambda re-validates everything: a server validating against a list the client shipped it is asking the caller what the rules are. And the Lambda is a separately deployed zip that cannot import from src/.

npm run check:intake is what keeps them honest — it imports both and asserts they agree on every field name, on which are required, on every length cap, and on every closed option set. Probed with three deliberate mismatches (a changed cap, a dropped field, a changed option); each was caught, exit 1.

Analytics: decided, not installed

D15 chose Plausible. §7 records that no script is on any page, and ANALYTICS.installed in src/data/site.ts is false. /legal/privacy/ renders its analytics paragraph from that flag, so today the policy says the site sets no cookies and runs no analytics — which is the fact. Flipping the flag is a change to a published disclosure, not a config edit: the policy changes on the same build and its last-updated date moves with it.

What this data actually is

The form collects, in a live legal dispute: the inquirer's identity and contact details, the names of opposing parties and their counsel, the nature of the dispute, and often the amounts at issue.

That is personal information about identifiable third parties who have not consented and do not know the submission happened. It is more sensitive than a typical contact form by a wide margin, and it is potentially conflict-relevant. Design accordingly. Nothing in this section is optional.

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Form fields

Field	Type	Required	Notes
Name	text	yes
Email	email	yes	Validated server-side, not only in the browser
Phone	tel	no
Role	select	yes	Counsel · In-house · Party · Institution · Other
Firm / organisation	text	no
Process sought	select	yes	Mediation · Arbitration · Med-Arb · ENE · Not sure
Practice area	select	yes	The six areas plus Other
Other parties	text	no	Surfaced for conflicts screening
Opposing counsel	text	no	Same
Matter summary	textarea	yes	2000 char cap. Hint: no privileged or confidential detail
Timing	select	no	Urgent · 30 days · 90 days · Exploring
Preferred contact	radio	no	Email · Phone
Consent	checkbox	yes	Explicit, unchecked by default, links to /legal/privacy/

Do not collect dollar amounts, document uploads, or anything the inquirer might reasonably treat as privileged. The intake call is for that.

Consent text

I consent to Pouya Lajevardi storing and using the information in this form to respond to my inquiry and to run a conflicts check. I understand that submitting this form does not create a retainer, does not appoint a neutral, and does not itself establish a mediator–party relationship.

Validation and abuse control

Client-side validation is a convenience. The Lambda re-validates everything.

• Required fields present; email well-formed; lengths within bounds
• Reject any field over its cap rather than truncating silently
• Honeypot field, hidden from sighted and screen-reader users, must be empty
• Timestamp check — reject submissions completed in under 3 seconds
• Rate limit by source IP at API Gateway: 5 requests / 5 minutes
• No CAPTCHA. It is a third-party script on a page collecting legal information, and the two controls above stop the traffic that matters
• CORS restricted to https://adr.smlcompany.ca — no wildcard
• Strip HTML from every field before storage and before it enters an email body

Storage

DynamoDB, in the region AGENTS.md §7 records. Canadian data residency is worth stating in the privacy policy: parties describing a live dispute are handing over sensitive material, and where it comes to rest is a fair question for them to ask. Confirm the existing table's region and migrate if it is elsewhere — §7 has the table name and region.

Attribute
pk	INTAKE#<uuid>
sk	<ISO-8601 timestamp>
fields	as above
sourceIp, userAgent	abuse investigation only
ttl	epoch seconds — the input to automatic deletion; see §Retention for why writing it is not the mechanism

Encryption at rest with a customer-managed KMS key. Point-in-time recovery on. Table access limited to the Lambda role and one named administrative principal.

Retention

24 months, enforced by DynamoDB TTL. Not a policy someone remembers — a mechanism that runs whether anyone remembers or not.

⚠️ WRITING THE ATTRIBUTE IS NOT THE MECHANISM. The handler supplies ttl; TTL must also be enabled on the table, and AGENTS.md §7 records whether it is — this section deliberately does not. So the paragraph above is a statement about the design and not about the running system until the cutover item below is ticked on both halves: ENABLED by command, and a test record observed to disappear.

Rationale: long enough to serve conflicts screening across a normal matter lifecycle; short enough to be defensible under PIPEDA's requirement to retain personal information only as long as necessary. Whatever number ships must match /legal/privacy/ exactly.

Notification

SES on submission:

• To Pouya: the full submission, plainly formatted, replyable to the inquirer.

• To the inquirer: confirmation of receipt, the response-time commitment, a repeat of the no-retainer language, and a link to the privacy policy. This email is the reason the form beats a mailto: link.

  The response time is a public commitment — two business days (§4, Q27). Render it from SITE.responseTime / SITE.responseTimeShort in src/data/site.ts; never retype it. It must read identically here, on /contact/, and in any bio.

SES production access is granted (Q19, 2026-08-26) — mail reaches unverified recipients, so the inquirer confirmation works. See §7 for the account state.

Bounce and complaint monitoring

Configured 2026-08-26; the resource names, thresholds and current state are in AGENTS.md §7. What matters here is why it is a real control rather than a formality:

At this volume a single bad address is a threshold event. SES suspends sending above roughly a 5% bounce rate. Under 100 messages a month, five bounces crosses it — and an intake form is exactly where mistyped addresses arrive. The alarms sit well below that line so there is room to react.

Bounces and complaints are handled by SES email feedback forwarding, which is on by default, not by an SNS feedback topic. That is deliberate: at this volume there is nothing to consume a programmatic feed, and an unused SNS topic is one more thing to keep correct. Revisit when code needs to act on a bounce — suppression lists, retry logic, marking a record undeliverable.

The alarms currently notify nobody. §7 records the ses-alerts email subscription as pending confirmation. An unconfirmed SNS subscription drops every message, so until the confirmation link is clicked the alarms fire into nothing. This is the first thing to check if /contact/ ships.

Email authentication — in place as of 2026-08-26 (Q20).

SPF and DMARC are both live and independently verified (Q20); mail is on Google Workspace with Google DKIM configured, and the SES domain identity is verified for sending. The record values, the MX, and the region are in AGENTS.md §7 — not restated here. An earlier version of this spec asserted that neither SPF nor DMARC existed; that was true when written and is no longer, which is the whole argument for citing §7 rather than copying it.

What is already in place. AGENTS.md §7 is the record — resource IDs, DNS records, DKIM token sets, and their verification state all live there and are not restated here. Read §7 before touching DNS.

Two points from §7 that this spec depends on, cited rather than copied:

• Only one of the two SES DKIM token sets resolves. §7 names both sets and marks which is which. The resolving set is what DMARC alignment rests on; deleting it breaks intake mail authentication silently. The other set is NXDOMAIN and inert. Do not act on any DKIM list that is not §7's.
• SES has no custom MAIL FROM, so SPF is unaligned and SES satisfies DMARC through DKIM alone.

Notes that mattered when these were added, kept because they matter again on any future edit: a domain may publish only one v=spf1 record, so both senders go in one string. Namecheap TXT values take no surrounding quotes — quoting them stores the quotes literally and breaks the record.

Correction to an earlier version of this spec. SPF is not what authenticates SES here. Without a custom MAIL FROM domain, SES uses an envelope sender at amazonses.com, so its SPF pass is not aligned with smlcompany.ca and does not satisfy DMARC. SES satisfies DMARC through DKIM alignment — that is what the three resolving DKIM CNAMEs above are doing, and it already works. (Six are present in the zone; only the f5pu / jdue / kznn set answers.) The SPF record's real job is authenticating Google Workspace mail, which currently has no SPF at all. include:amazonses.com is harmless and becomes useful if a custom MAIL FROM domain is configured later.

Start DMARC at p=none — it collects reports without affecting delivery. Move to quarantine only after reports come back clean. Reports arrive as XML attachments, so filter them in Gmail, or drop rua= entirely and accept having no visibility.

Do not delete the ACM validation CNAMEs. They are how the certificate for adr.smlcompany.ca auto-renews. Removing them breaks HTTPS at the next renewal — silently, months later.

Failure handling: SES failure must never lose the submission. Write to DynamoDB first, then send. A dead-letter queue on the Lambda, and a CloudWatch alarm on DLQ depth ≥ 1.

Booking

PARKED — R6, and /contact/ ships without it. Pouya parked the booking tool on 2026-08-26; build step 8 shipped the form and no embed. The "reserved slot" docs/01 asks for is CONTACT.bookingUrl being null: nothing renders, and a URL there brings the block back without a rebuild of the page.

Nothing on /contact/ mentions booking, deliberately — a page that says "book a call" with no way to book one is worse than a page that says to email. D10 committed to booking because it removes the back-and-forth that loses appointments, so the form alone is a partial answer and R6 stays live.

An embedded scheduler for the 30–45 minute confidential intake call (Q5 — tool not yet chosen).

• Prefer a provider with Canadian or EU data residency and no advertising business. Cal.com self-hosted is the strongest privacy posture; Cal.com cloud or Calendly are acceptable.
• Lazy-load behind a click. No third-party iframe on first paint, and no third-party script on any other page.
• Provide a plain link fallback that works with JavaScript disabled.
• The booking page must carry the same no-retainer language.
• Disclose the provider by name in /legal/privacy/.

Security headers

Note added 2026-08-26 — style-src has acquired a dependency. The site now ships inline style="…" attributes that are load-bearing rather than decorative: InfinityMark.astro sets its own block-size that way, and the step-1 proof sheet rendered computed swatches with it (that page was deleted at build step 2; the mechanism is what matters here). They are fine under style-src 'self' 'unsafe-inline' as specified below. They would not survive a move to hashed or nonce'd styles — the infinity mark would collapse. Price that before tightening style-src, and read the components first. script-src is unaffected, and has got easier: the site ships zero JavaScript, so script-src 'self' needs no hash and no nonce (AGENTS.md §7). That is why the reveal moved from an inline observer to CSS.

Set at CloudFront via a response-headers policy:

Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: geolocation=(), microphone=(), camera=(), interest-cohort=()
Content-Security-Policy: default-src 'self'; img-src 'self' data:;
  style-src 'self' 'unsafe-inline'; script-src 'self';
  frame-src <booking-provider>; form-action 'self' <api-endpoint>;
  base-uri 'self'; frame-ancestors 'none'

⚠️ form-action IS NOW 'self' ALONE, and that is tighter than the line above. Build step 8 posts the intake form to the same-origin path /api/intake rather than to the execute-api hostname, so no third-party origin needs to appear in the policy. Drop <api-endpoint> from form-action when the policy is written. frame-src <booking-provider> is also unnecessary while R6 keeps the embed parked — add it with the embed, not before.

Tighten CSP once the booking provider is chosen. unsafe-inline on styles is tolerable for critical CSS; unsafe-inline on scripts is not — use a hash or nonce for the reveal script.

Privacy policy must state

Written to match what is actually built, not what is typical:

What is collected · why · lawful basis (consent) · where it is stored (DynamoDB, region, encrypted at rest) · the retention period and that deletion is automatic · who can access it · third parties involved (AWS, SES, the booking provider, analytics if any) · how to request access or deletion and the address to use · that submitting the form creates no retainer and no mediator–party relationship · cookie and analytics disclosure · last-updated date.

If analytics ship, prefer a cookieless privacy-preserving tool (Plausible, Fathom). GA4 on a page collecting legal-dispute information is a poor fit for a practice whose privacy posture is part of its offer — D15 settles this: Plausible or Fathom, cookieless, no consent banner.

Definition of done

• Server-side validation independent of the client — backend/intake/fields.mjs, cross-checked by npm run check:intake
• Honeypot live. ⚠️ The timing check is NOT implemented — see deviation 1 above; it is unimplementable on a CDN-cached static page and would be a control that does nothing
• Rate limit configured — API Gateway throttling, 5 requests / 5 minutes per source IP. Not expressible in handler code; not done
• The form's own protection is the Origin check, not CORS — see deviation 2. CORS on the endpoint still to be restricted for scripted calls
• TTL set and verified by test record. ⚠️ THIS ONE BACKS A PUBLISHED PROMISE, AND THE SETTING WAS MEASURED OFF ON 2026-08-31. /legal/privacy/ states that records are deleted automatically after 24 months. The handler writes the ttl attribute — epoch seconds, 24 months, confirmed against this spec [verified 2026-08-31] — but describe-time-to-live returned DISABLED when Pouya first ran it, so the page promised a mechanism that was not running, from the day it was written. Enabling was initiated the same day with AttributeName=ttl; §7 records the state and deliberately does not yet stamp ENABLED. The test record is what closes this, not the status: ENABLED proves the setting, a record written with a near-future ttl and observed to vanish proves the behaviour
• KMS customer-managed key and PITR enabled. Neither is claimed on /legal/privacy/ — the page says "encrypted at rest", which is true of every DynamoDB table unconditionally, and does not mention either of these because §7 does not verify them
• Both emails send; SPF/DKIM/DMARC aligned; inbox-tested, not spam-tested
• DLQ and CloudWatch alarm configured. The handler writes to DynamoDB before sending mail, so a replay cannot lose a submission
• Form usable by keyboard only. Errors are announced by the browser's own validation, which with no script is the only thing that can announce them inline — role="alert" needs a live region and something to write into it
• Works with JavaScript disabled — replacing the mailto: degradation item; see deviation 3
• Privacy policy matches the implementation — and three of its statements are DERIVED rather than written, so they cannot drift: the collected-data list renders from INTAKE_FIELDS, the retention period from the handler's own figure, and the analytics paragraph from ANALYTICS.installed
• CloudFront /api/* behaviour created, routing to the HTTP API origin §7 records. The form does not work without it
• Handler deployed, replacing the hand-built adr-intake-handler, with SIX variables set: INTAKE_TABLE, SITE_ORIGIN, NOTIFY_TO, MAIL_FROM, RESPONSE_TIME and NO_RETAINER_NOTICE. It throws at cold start on any missing one, deliberately. ⚠️ This item said five while the handler required six. NO_RETAINER_NOTICE became a requireEnv and reached no document, so an operator following the list would have deployed a function that throws on every invocation — 5xx from API Gateway, and every inquiry lost from the moment /api/* was wired. Found by adversarial-reviewer, 2026-08-31. Two of the six must be verbatim from src/data/site.ts, because both are published commitments: RESPONSE_TIME from CONTACT.responseTime, and NO_RETAINER_NOTICE from the constant of the same name — whose fourth clause ("does not itself create a conflict check", required by docs/01 §/contact/) a hand-typed copy in the handler had dropped