Lattice Plugin API

The plugin API is the WIT package lattice:plugin-host@0.1.0 — 31 interfaces ("seams") and 25 worlds. It is the whole contract: a plugin written in any language with Component-Model tooling (Rust, Go, Zig, JavaScript, …) sees exactly what is on these pages and nothing else. This reference is generated from the .wit files in crates/lattice-wit/wit/, so it cannot disagree with them.

New to writing plugins? Start with the plugin authoring guide, then come back here for the detail. The same reference in machine-readable form — every seam, signature, type and member — is docs/dev/reference/plugin-api.json in the repository and /plugin-api.json on the documentation site.

How to read this reference

• A plugin targets one world. The world decides which seams the plugin exports (implements — the host calls it) and which it imports (calls into the host). In Rust: wit_bindgen::generate!({ world: "comment-plugin", path: "…/wit" }).
• Direction on each seam says which of those it is. A seam marked shared types only is never called; other seams use its types.
• Capability is what the seam requires of a plugin's grant. Most are none: the host does the I/O and hands the guest data.
• Resources (resource document) are handles to host-owned state. A borrow<document> parameter is valid for that call only.
• Errors are result<T, string>: an err carries a message the host surfaces to the user, so it should say what went wrong.
• WIT to Rust (wit-bindgen): kebab-case becomes snake_case for functions and fields and UpperCamelCase for types; list<T> is Vec<T>, option<T> is Option<T>, result<T, E> is Result<T, E>, borrow<r> is &R.

Worlds (25)

Each world's entry points — the register-* functions the host calls on load — are on the worlds page.

Seams (31)