---
name: prepare-line-stickers
description: Prepare local sticker artwork and generated videos for static or animated LINE submission, including crop inspection, transparency processing, export validation, and ZIP packaging. Use when the user has source assets to process.
---

# Prepare LINE stickers

This is an instruction-only starter workflow, not a bundled converter. Use available file and code tools to implement processing. State missing dependencies and unverified results. Do not claim a real pack has passed validation unless its actual output files were checked.

## Inputs and scope

Read the user's plan and inspect the supplied assets. Match sticker IDs to the intended actions. Preserve source files; create derived assets in separate directories. Respect the requested platform, count, captions, and style. Do not invent missing artwork or silently substitute simple motion for AI-generated movement.

If the user requests a sample checkpoint, process that sticker first and wait for their feedback before processing the rest. This workflow does not authorize paid generation, account changes, or submission to LINE.

## Crops and transparency

- Inspect actual artwork positions instead of blindly splitting a generated sheet into equal cells. Keep detached limbs, props, and other intended elements with their sticker. Flag ambiguous crops.
- Verify alpha values; a visible checkerboard is not proof of transparency.
- For solid-background sources, derive a mask that preserves similar foreground colors. Border connectivity can help isolate exterior background, but enclosed background gaps need separate inspection. Use segmentation or manual correction when color separation is inadequate.
- For animation, derive a stable crop across the entire motion. Do not resize or recenter independently on every frame. Keep limbs within the canvas throughout the clip.
- Inspect edges, color spill, foreground holes, motion consistency, and loop transitions on light and dark previews. Bad anatomy or identity drift in source media may require regeneration, not masking.

## Export

Read the current official specifications before building the exporter:

- Animated assets: https://creator.line.me/en/guideline/animationsticker/
- Frame order and timing: https://creator.line.me/en/guideline/animationsticker/detail/
- Static assets: https://creator.line.me/en/guideline/sticker/

Keep a dated requirements snapshot in the job's validation report. If the pages cannot be accessed, disclose that and label specification compliance unverified rather than inventing current limits.

Prepare separately named static and animated submission directories. Encode actual APNG data with a .png extension for animated files. Include the required main image and chat thumbnail for each submission type. Use the first animation frame to communicate the sticker's main feeling, and account for its timing when building the complete sequence.

Choose an encoder and verify its output by decoding it. Never infer validity from the extension or requested encoder settings. Validate canvas dimensions, frame dimensions and offsets, timing, loop count, changing frame data, color mode, real transparency, and file size against the requirements. Revalidate after any compression or optimization. Preserve full-quality source assets outside the submission directories.

## Deliver

Create numbered static contact sheets and animated previews on light and dark backgrounds. Report individual filenames, dimensions, frame counts, loop and playback timing, sizes, and pass/fail/unverified checks. Separate automated checks from visual checks and from LINE acceptance, which this workflow cannot guarantee.

Package submission assets only, with no reports, source videos, hidden files, or preview sheets inside the submission ZIPs. Keep reports and previews alongside the archives. Flag incomplete sets and failures explicitly instead of labeling them ready. Finish with paths to actual output files and the remaining checks for the user.