06 Platform Adapters

Platform Adapters

Platform adapters apply formatting rules when content is prepared for a specific channel. Each of the 18 content types has a spec that controls truncation, structure, and constraints.

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Adapter Rules by Platform

LinkedIn

Rule	Value
Max chars	3,000
Truncation	First 140 chars visible
Format	Plain (no markdown)
Hashtags	Max 3, at end
Structure	hook → insight → proof → CTA
Best length	300–1200 chars
Comment max	1,250 chars

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X / Twitter

Rule	Value
Max chars	280 (standard), 25,000 (premium)
Format	Plain
Thread format	(1/n) for threads
Structure	hook → punch
Best length	200–280 chars

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Reddit

Rule	Value
Max chars	40,000
Title max	300
Format	Markdown
TL;DR	If >300 words
Structure	context → thesis → evidence → discussion
Best length	400–1500 words

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Reddit Comment

Rule	Value
Max chars	10,000
Format	Markdown
Structure	direct answer → supporting detail
Best length	50–300 words
Tone	Conversational

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Instagram

Rule	Value
Max chars	2,200
Truncation	125
Hashtags	Max 5
Emojis	Count as 2 chars each
Format	Plain
Structure	hook → story → CTA → hashtags
Best length	125–500 chars

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Facebook

Rule	Value
Max chars	63,206
Truncation	125 mobile, 477 desktop
Format	Plain
Structure	hook → value → engagement question
Best length	40–250 chars
Key rule	Front-load message

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TikTok

Rule	Value
Max chars	4,000
Truncation	100
Hashtags	Max 5
Format	Plain
Structure	hook (first line) → context → CTA → hashtags
Best length	100–300 chars
Key rule	Hook-first

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YouTube

Rule	Value
Max chars	5,000
Truncation	200
Format	Plain
Structure	summary → timestamps → links → about → tags
Best length	200–1000 chars
Key rule	Timestamps, chapters

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Substack

Rule	Value
Max chars	Unlimited
Format	HTML
Structure	hook → H2/H3 sections → pull quotes → CTA
Best length	800–3000 words
Key rule	Pull quotes, H2/H3

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Email

Rule	Value
Subject max	60 chars
Preheader max	90 chars
Format	html+plain
Structure	subject → preheader → greeting → body → CTA → sign-off
Best length	50–300 words

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Blog Post

Rule	Value
Meta desc max	160
Format	Markdown
Structure	H1 → intro hook → H2 sections → conclusion → meta
Best length	800–2500 words
Key rule	H2/H3, meta <160

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White Paper

Rule	Value
Format	Markdown
Structure	exec summary → problem → methodology → findings → recommendations → citations
Best length	2000–5000 words
Key rule	Executive summary, citations

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Website Copy

Rule	Value
Format	HTML
Structure	headline → subhead → benefits → social proof → CTA
Best length	300–800 words
Key rule	Conversion copy

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Reply

Rule	Value
Format	Context-matched
Structure	acknowledgment → direct answer → supporting point
Best length	50–200 words
Key rule	Context-matched to prior message

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Threads

Rule	Value
Max chars	500
Format	Plain
Structure	Complete thought in 500 chars
Best length	100–500 chars

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Medium

Rule	Value
Max tags	5
Format	Markdown
Structure	hook → sections → conclusion
Best length	800–2500 words
Subtitle	Yes
Key rule	5 tags, subtitle

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Pinterest

Rule	Value
Max chars	500
Format	Plain
Structure	benefit → description → keywords
Best length	100–300 chars
Key rule	Keyword-rich, no hashtag spam

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Google Business Profile (GBP)

Rule	Value
Max chars	1,500
Format	Plain
Structure	update/offer → details → CTA button
CTA types	Learn More, Book, Order, Call, Sign Up
Best length	150–300 chars

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Normalization (All Platforms)

Before platform-specific formatting, all content is normalized:

• Strip zero-width chars (U+200B–U+200F, U+2028–U+202F, U+FEFF)
• Replace non-breaking space with regular space
• Normalize smart quotes to ASCII
• Normalize en-dash/em-dash
• Normalize ellipsis
• Collapse multiple spaces