Findings Catalog

Synapse Inspect includes 130+ finding codes across many categories, spanning email, push, in-app, SMS, and WhatsApp. Each code is a stable identifier -- codes are never removed or renumbered. New codes are added over time but existing ones remain unchanged.

Severities

Severity	Meaning	Send Impact
`critical`	Broken rendering or deliverability risk	Blocks send (unless overridden)
`warning`	Should be fixed but won't break delivery	Does not block
`info`	Best practice recommendation	Does not block

Finding Structure

Every finding returned by the API has this structure:

Field	Type	Description
`code`	string	Stable identifier (e.g., `HTML_MISSING_DOCTYPE`)
`severity`	string	`critical`, `warning`, or `info`
`category`	string	One of the 10 categories above
`title`	string	Short human-readable title
`description`	string	Detailed explanation of the issue
`fix_text`	string	Actionable fix instructions
`ast_node_id`	string or null	Links to a specific block in the template editor
`client_specific`	string or null	Which email client this affects (e.g., `outlook_2019`)
`context`	object or null	Additional context data for the finding

Actions

Each finding supports one or more actions:

Action	Description
`auto_fix`	Synapse can automatically fix this issue (see Auto-Fixers)
`snooze`	Temporarily dismiss the finding (1--365 days)
`mark_fixed`	Mark as manually fixed
`mark_false_positive`	Dismiss as a false positive

Sample Findings by Category

HTML

Code	Severity	Title
`HTML_MISSING_DOCTYPE`	critical	Missing DOCTYPE declaration
`HTML_MISSING_CHARSET`	critical	Missing charset declaration
`HTML_MISSING_LANG`	warning	Missing lang attribute on `<html>`
`HTML_MISSING_VIEWPORT`	warning	Missing viewport meta tag
`HTML_DEPRECATED_TAG`	warning	Deprecated HTML tag used
`HTML_INVALID_NESTING`	warning	Invalid HTML nesting
`HTML_MISSING_TITLE`	info	Missing `<title>` tag

Dark Mode

Code	Severity	Title
`DARK_MODE_NO_META`	warning	Missing color-scheme meta tag
`DARK_MODE_NO_CSS_SCHEME`	warning	Missing supported-color-schemes meta
`DARK_MODE_HARDCODED_BG`	warning	Hardcoded background color without dark variant
`DARK_MODE_HARDCODED_TEXT`	warning	Hardcoded text color without dark variant
`DARK_MODE_LOGO_NO_SWAP`	warning	Logo image without dark mode swap

Accessibility

Code	Severity	Title
`A11Y_MISSING_ALT`	warning	Image missing alt text
`A11Y_LINK_NO_TEXT`	warning	Link without descriptive text
`A11Y_LOW_CONTRAST`	warning	Low color contrast ratio

Spam

Code	Severity	Title
`SPAM_KEYWORD_FOUND`	warning	Spam trigger keyword detected
`SPAM_SCORE_HIGH`	critical	High spam score
`SPAM_ALL_CAPS_SUBJECT`	warning	Subject line is all caps

Subject & Preheader

Code	Severity	Title
`SJ001`	warning	Subject line missing
`SJ007`	warning	Preheader text missing

Note

Subject and preheader on content-only templates. Synapse templates are content-only, so a template body has no <title> or hidden preheader element for these checks to read — SJ001 and SJ007 would fire on every template unless you tell Inspect what the email will actually send with. Pass subject and preheader on POST /v1/inspect: supplying subject suppresses SJ001, and supplying preheader suppresses SJ007. When no subject is supplied, SJ001 is reported as a warning (not a hard block), since a subject legitimately resolves at send time from the flow step, campaign, or template. This is how the dashboard and pre-send checks evaluate the complete email rather than the bare fragment.

SMS

Full guide: SMS Quality Checks.

Code	Severity	Title
`SMS_NLT_REQUIRED_MISS`	critical	Required NLT field is missing on the sample contact
`SMS_NLT_UNRESOLVED_EXPRESSION`	warning	SMS body has unresolved NLT expressions
`SMS_UCS2_FORCED`	warning	A non-GSM-7 character forces expensive UCS-2 encoding
`SMS_MULTI_SEGMENT`	warning	SMS body spans multiple segments
`SMS_BODY_TOO_LONG`	warning	SMS body spans many segments
`SMS_NO_OPT_OUT_LANGUAGE`	warning	SMS body has no opt-out / STOP language
`SMS_FROM_NUMBER_INVALID`	warning	Template `from_number` is not a valid E.164 number

Full guide: WhatsApp Pre-Submission Inspect.

Code	Severity	Title
`WA_NLT_REQUIRED_MISS`	critical	Required NLT field is missing on the sample contact
`WA_NLT_UNRESOLVED`	warning	WhatsApp template has unresolved NLT expressions
`WA_VARIABLE_COUNT_MISMATCH`	warning	Placeholder count does not match the declared variable schema
`WA_PLACEHOLDER_NOT_SEQUENTIAL`	warning	Placeholders are not numbered sequentially from 1
`WA_PLACEHOLDER_ADJACENT_OR_EDGE`	warning	Placeholders are adjacent or at the body's start/end
`WA_BODY_OVER_LIMIT`	warning	Template body exceeds Meta's 1024-character limit
`WA_CATEGORY_INVALID`	warning	Template category is not a valid Meta category

Note

The WhatsApp catalog also defines WA_HEADER_OVER_LIMIT, WA_FOOTER_OVER_LIMIT, and WA_BUTTON_LABEL_OVER_LIMIT. These are reserved for when header / footer / button components are stored — the current template model stores the body only, so they do not fire on today's templates. See the WhatsApp guide.

Note

This page shows a representative sample. The full catalog includes 130+ codes.

Category	Channel	Description	Example Code
`html`	Email	HTML structure and validity	`HTML_MISSING_DOCTYPE`
`css`	Email	CSS compatibility across email clients	`CSS_SHORTHAND_ISSUE`
`images`	Email	Image format, size, and optimization	`IMG_MISSING_ALT`
`links`	Email	Broken links, redirect chains, tracking	`LINK_BROKEN`
`spam`	Email	Spam trigger words and patterns	`SPAM_TRIGGER_WORDS`
`accessibility`	Email	Screen reader and accessibility compliance	`A11Y_LOW_CONTRAST`
`rendering`	Email	Cross-client rendering issues	`RENDER_CLIENT_DEVIATION`
`dark_mode`	Email	Dark mode support and compatibility	`DARK_MODE_NO_META`
`subject`	Email	Subject line and preheader quality	`SUBJECT_TOO_LONG`
`tracking`	Email	UTM parameters and tracking links	`TRACKING_UTM_MISSING`
`push`	Push	Payload size, per-platform length, deep links, NLT	`PUSH_PAYLOAD_APNS_OVERSIZE`
`in_app`	In-app	Placement, payload size, CTA limits, NLT	`IN_APP_PAYLOAD_OVERSIZE`
`sms`	SMS	Segments & encoding, opt-out, sender number, NLT	`SMS_MULTI_SEGMENT`
`whatsapp`	WhatsApp	Meta placeholder rules, body limit, category, NLT	`WA_VARIABLE_COUNT_MISMATCH`