A development toolkit for building private plugins for TRMNL e-ink devices, which use low-power screens that update periodically. It covers the plugin's data, display templates, device connection, local previews, and refresh timing.

Use it to create or maintain TRMNL OG and TRMNL X plugins, send webhook data, write Liquid display templates, test previews, and run the plugin's stateless JSON-RPC server.

It brings the device-specific parts of a TRMNL plugin into one workflow, including checks for how often the battery-powered screen should refresh.

trmnl-dev — Skill for Claude Code and Codex by 0juano/agent-skills

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add 0juano/agent-skills --skill trmnl-dev

Clone the repo

git clone --depth 1 https://github.com/0juano/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/0juano/agent-skills/trmnl-dev/github.svg)](https://agentmods.dev/skills/0juano/agent-skills/trmnl-dev)

Your own site

<a href="https://agentmods.dev/skills/0juano/agent-skills/trmnl-dev"><img src="https://agentmods.dev/badge/skills/0juano/agent-skills/trmnl-dev/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/0juano/agent-skills/trmnl-dev"><img src="https://agentmods.dev/badge/skills/0juano/agent-skills/trmnl-dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 117 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,400 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00117	$0.02400
Opus 5.5	$0.00047	$0.00960
Sonnet 5.5	$0.00023	$0.00480
Haiku 4.5	$0.00012	$0.00240

Measured 2mo ago against content hash 2ed0c8e4147f, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

trmnl-dev scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl "https://trmnl.com/api/custom_plugins/${TRMNL_PLUGIN_UUID}" \

trmnl-dev/SKILL.md · 181 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 181 lines · 117 tokens per session scan A 2ed0c8e4147f

Subscribe to this mod's changes

trmnl-dev is a skill published in the GitHub repository 0juano/agent-skills (0 stars, last pushed 4mo ago), with no licence file. It adds 117 tokens to every session and 2,400 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.

Hardware and IoT

trmnl-dev next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
trmnl-dev0juano/agent-skills	Skill	0	4mo ago	none	A	117	Claude Code, Codex
gke-compute-classesgoogle/skills	Skill	23k	today	Apache-2.0	A	83	Claude Code, Codex
jetson-diagnosticNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	30	Claude Code, Codex
holoscan-install-wheelNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	34	Claude Code, Codex
offensive-z-waveSnailSploit/Claude-Red	Skill	10k	25d ago	MIT	A	113	Claude Code, Codex
doca-socket-relayNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	236	Claude Code, Codex
hsb-flashNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	B	94	Claude Code

trmnl-dev

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Makes network callslowCapability

The source is not reproduced here

No licence file

What ships with it

What this file has done since we first saw it

trmnl-dev compared with skills from other repositories