merman-typst-plugin

merman-typst-plugin is the experimental Typst WebAssembly plugin bridge for merman.

The crate exports Typst-compatible wasm-minimal-protocol functions and delegates rendering and validation to merman-bindings-core.

Current exported functions:

• abi_version() -> bytes
• package_version() -> bytes
• capabilities_json() -> bytes
• render_svg_json(source: bytes, options_json: bytes) -> bytes
• validate_json(source: bytes, options_json: bytes) -> bytes

render_svg_json returns a stable JSON payload with ok, code, code_name, message, and svg fields so the Typst package can render placeholder or text errors without failing compilation.

ABI Boundary

Current Typst plugin ABI version: 1.

The plugin ABI covers the exported wasm-minimal-protocol function names and their byte payload contracts. That includes the abi_version, package_version, capabilities_json, render_svg_json, and validate_json exports, plus the JSON schemas consumed or produced by those exports.

Typst wrapper API changes in packages/typst/merman/src/*.typ do not require a plugin ABI bump when this WebAssembly surface remains stable. Bump TYPST_PLUGIN_ABI_VERSION and update the ABI tests and package README mapping when an export is added, removed, renamed, changes argument or return bytes, or changes the render, validate, or capabilities JSON contract.

The package_version export reports the Rust crate version. The Typst package version in packages/typst/merman/typst.toml is a separate @preview wrapper version.

Build the default Typst render artifact with:

cargo build -p merman-typst-plugin --profile wasm-size --target wasm32-unknown-unknown

Build the bridge-only protocol artifact with:

cargo build -p merman-typst-plugin --profile wasm-size --target wasm32-unknown-unknown --no-default-features

Build a pure render artifact without validation analysis with:

cargo build -p merman-typst-plugin --profile wasm-size --target wasm32-unknown-unknown --no-default-features --features render

Build the larger full-config/full-sanitization no-host artifact with:

cargo build -p merman-typst-plugin --profile wasm-size --target wasm32-unknown-unknown --features core-full

Then check the Typst wasm surface with:

cargo run -p xtask -- profile-budget check-wasm --profile typst-wasm --wasm target/wasm32-unknown-unknown/wasm-size/merman_typst_plugin.wasm

Smoke the plugin through a Typst-compatible wasmi host call with:

cargo run -p xtask -- typst-plugin-smoke --wasm target/wasm32-unknown-unknown/wasm-size/merman_typst_plugin.wasm