trmnl

TRMNL Content Generator

Generate HTML content for TRMNL e-ink display devices.

Prerequisites

Install the trmnl CLI to the latest version:

npm install -g trmnl-cli@latest

Configure a webhook plugin (one-time setup):

# Add a plugin
trmnl plugin add home "https://trmnl.com/api/custom_plugins/{uuid}"

# Verify it's configured
trmnl plugin

Quick Start Workflow

1. Install/update CLI: Run npm install -g trmnl-cli@latest
2. Check plugins: Run trmnl plugin - if none, prompt user to add one
3. Confirm device type (default: TRMNL OG, 2-bit, 800x480)
4. Read relevant reference docs based on content needs
5. Generate HTML using TRMNL framework classes
6. Write HTML to a temp file and send:

   trmnl send --file /tmp/trmnl-content.html
   # Or to a specific plugin:
   trmnl send --file /tmp/trmnl-content.html --plugin office
   

7. Minimal confirmation only - Do NOT echo content back to chat

Sending Content

From file (recommended):

# Write HTML content to file first
cat > /tmp/trmnl-content.html << 'EOF'
<div class="layout layout--col gap--space-between">
  <div class="item">
    <span class="value value--xlarge value--tnums">Hello TRMNL!</span>
  </div>
</div>
<div class="title_bar">
  <span class="title">My Plugin</span>
</div>
EOF

# Send to display
trmnl send --file /tmp/trmnl-content.html

Validate before sending:

trmnl validate --file /tmp/trmnl-content.html

View send history:

trmnl history
trmnl history --today
trmnl history --failed

Webhook Limits

Tier	Payload Size	Rate Limit
Free	2 KB (2,048 bytes)	12 requests/hour
TRMNL+	5 KB (5,120 bytes)	30 requests/hour

Set tier globally for accurate validation:

trmnl tier plus  # or "free"

Reference Documentation

Read these files as needed:

File	When to Read
references/patterns.md	Start here - Common plugin patterns
references/framework-overview.md	Device specs, e-ink constraints
references/css-utilities.md	Colors, typography, sizing, spacing
references/layout-systems.md	Flexbox, grid, overflow engines
references/components.md	Title bar, dividers, items, tables
references/webhook-api.md	Payload format, troubleshooting
assets/anti-patterns.md	Common mistakes to avoid

Standard Plugin Structure

Every plugin follows this pattern:

<div class="layout layout--col gap--space-between">
  <!-- Content sections separated by dividers -->
</div>
<div class="title_bar">
  <img class="image" src="icon.svg">
  <span class="title">Plugin Name</span>
  <span class="instance">Context</span>
</div>

• layout + layout--col = vertical flex container
• gap--space-between = push sections to edges
• title_bar = always at bottom, outside layout
• divider = separate major sections
• CRITICAL: Only ONE .layout element per view

Quick Reference

Grid System (10-Column)

<div class="grid">
  <div class="col--span-3">30%</div>
  <div class="col--span-7">70%</div>
</div>

Item Component

<div class="item">
  <div class="content">
    <span class="value value--xlarge value--tnums">$159,022</span>
    <span class="label">Total Sales</span>
  </div>
</div>

Value Typography

Always use value--tnums for numbers.

Class	Usage
value--xxxlarge	Hero KPIs
value--xxlarge	Large prices
value--xlarge	Secondary metrics
value--tnums	Required for numbers

Grayscale Classes

Use dithered classes, not inline colors:

• bg--black, bg--gray-60, bg--gray-30, bg--gray-10, bg--white
• text--black, text--gray-50

Data Attributes

Attribute	Purpose
data-fit-value="true"	Auto-resize text to fit
data-clamp="N"	Limit to N lines
data-overflow="true"	Enable overflow management

Best Practices

1. Use layout + title_bar structure
2. Always value--tnums for numbers
3. Use data-fit-value on primary metrics
4. Use bg--gray-* dithered classes
5. Keep payload under tier limit
6. Minimal confirmations - just "Sent to TRMNL"

Troubleshooting

Problem	Solution
trmnl: command not found	Run npm install -g trmnl-cli@latest
No plugins configured	Run trmnl plugin add <name> <url>
Webhook fails	trmnl config - verify plugin URL
Payload too large	trmnl validate --file - check size
Numbers misaligned	Add value--tnums class
Send history	trmnl history --failed