v0.4.0 — MCP tools say what they do, return what they declare, and check a layout

MCP server

• Every tool declares a title, read-only / idempotent annotations, a closed input schema and an outputSchema, and returns matching structuredContent. The JSON text block is kept for older clients.
• New check_safe_area tool: reports whether a caption, logo or button box stays inside a placement's safe area, and by how many px it intrudes past each edge. TikTok answers unknown with the reason, instead of a guess.
• Errors you can fix: caller mistakes come back as tool errors (isError: true) that say how to fix the call, for example by listing the valid placement ids. Before, a missing width or duration produced NaN, an unknown subtitle target silently became vtt, and too few taps returned null.
• convert_subtitles reports the detected input format and accepts fromFormat.
• initialize negotiates the protocol version (2025-06-18, 2025-03-26, 2024-11-05) and sends server instructions.
• Official MCP Registry: listed as com.prismposter/creator-tools, with the hosted endpoint https://www.prismposter.com/api/mcp.

Package

• Node 20 or later is required now (engines); Node 18 has been end of life since April 2025. CI tests Node 20, 22 and 24.
• Dev tooling: vitest 4.1.11; npm audit reports 0 issues.
• Publishing: releases publish from CI through npm trusted publishing, with provenance.