README.md

Foundry Zed extension

Solidity support for Zed, using forge lsp --stdio and the language server's forge fmt integration. Install a version of Foundry that supports forge lsp --stdio. The extension never searches for, launches, or downloads a standalone Solar.

The extension ID and language server ID remain solar; the language remains Solidity. Existing language preferences and initialization options keep their names. The language server implementation remains in Foundry's solar_lsp dependency.

Configuration

By default, the extension resolves forge from the worktree's shell PATH. Zed launches forge lsp --stdio in the worktree directory, allowing version-manager shims to select the project's Forge installation. The extension does not run a separate capability probe because Zed's process API cannot set its working directory. Missing Forge on PATH produces installation guidance; missing custom executables and incompatible builds are reported by Zed's language server status/log during startup. To check an installation, run forge lsp --stdio --help from the worktree directory.

To select a specific Forge installation, set its absolute path in your Zed user or project settings:

{
  "lsp": {
    "solar": {
      "settings": {
        "forgePath": "/absolute/path/to/foundry/target/debug/forge"
      }
    }
  }
}

Windows paths are supported as well, for example C:\\Foundry\\forge.exe. This one setting selects the language server, formatter, and Forge checks. The extension sends the selected path as the existing forgePath initialization option. The worktree environment is inherited, including FOUNDRY_PROFILE; lsp.solar.binary.env can supply environment overrides.

Migration from Solar

Remove old lsp.solar.binary.path and lsp.solar.binary.arguments overrides. Zed applies those directly and bypasses the extension's command resolution, so they retain their original raw language server meaning; they are not reinterpreted as Forge paths. The extension rejects those overrides during initialization with migration instructions. Use lsp.solar.settings.forgePath for Forge instead.

If you set lsp.solar.initialization_options.forgePath, move that value to lsp.solar.settings.forgePath and remove the old entry. A conflicting old value is rejected instead of silently mixing Forge installations. Other initialization options pass through unchanged.

Remove any external forge fmt formatter override left from the old extension. Zed's default language server formatting uses the current unsaved buffer and the owning Foundry project's formatter configuration. To select it explicitly:

{
  "languages": {
    "Solidity": {
      "language_servers": ["solar", "!solidity"],
      "formatter": { "language_server": { "name": "solar" } },
      "format_on_save": "on"
    }
  }
}

Manual formatting is available through Zed's editor: format command. Do not combine external formatting and language server formatting in a formatter list: that would format the document twice. To disable formatting, set languages.Solidity.formatter to "none".

Build and local installation

Run these from the Foundry repository root. The extension has its own Cargo workspace and lockfile, so normal Foundry builds do not build Zed or WASM.

cargo build --locked -p forge --bin forge
./target/debug/forge lsp --stdio --help
cargo test --manifest-path editors/zed/Cargo.toml --locked
cargo clippy --manifest-path editors/zed/Cargo.toml --locked --all-targets -- -D warnings
cargo +nightly fmt --manifest-path editors/zed/Cargo.toml -- --check
rustup target add wasm32-wasip2
cargo build --manifest-path editors/zed/Cargo.toml --locked --release --target wasm32-wasip2

The standalone build produces editors/zed/target/wasm32-wasip2/release/zed_solar.wasm. Zed's dev extension installer builds that component, fetches the pinned tree-sitter grammar, and places extension.wasm and grammars/solidity.wasm in this extension directory. These generated files are ignored by Git. Rust and a C compiler are required for the dev installer, with network access for uncached dependencies and the grammar.

After dev installation has built both WASM files, a local portable archive can be created without copying the Cargo target directory or grammar checkout:

mkdir -p target/editor-dev
tar -czf target/editor-dev/zed-solar-local.tar.gz -C editors/zed \
  extension.toml extension.wasm languages grammars/solidity.wasm \
  GRAMMAR-LICENSE README.md -C ../.. LICENSE-MIT LICENSE-APACHE

This archive is for local inspection/distribution; store release and registration are separate maintainer tasks. The archive reads the license texts directly from the repository root, including in checkouts with core.symlinks=false.

1. Launch Zed with a new --user-data-dir; its settings live in config/ under that directory. On macOS, the normal CLI can forward to an existing instance even with this flag. To keep existing windows and settings separate, launch the app executable directly from a terminal with its stateless test mode:

   ZED_STATELESS=1 /Applications/Zed.app/Contents/MacOS/zed \
     --user-data-dir "$PWD/target/editor-dev/zed-user-data" \
     "$PWD/target/editor-dev/project"

   Run node editors/prepare-vscode.mjs first to create that scratch project. Stateless mode uses an in-memory session database. Terminal output contains the startup logs; retain it for process verification. On other platforms use a separately isolated instance with zed --user-data-dir <new-directory>.

2. Configure lsp.solar.settings.forgePath in that isolated profile to the absolute path of this checkout's target/debug/forge.

3. Run zed: install dev extension from the command palette and select this repository's editors/zed directory.

4. Open a Foundry project and a Solidity file. In dev: open language server logs, check that the server command is the selected forge lsp --stdio. Check diagnostics, hover/navigation, and format an unsaved edit while using a distinctive [fmt] setting in the project's foundry.toml. Trust only the scratch worktree when Zed prompts, so its language server can start.

5. After extension changes, run zed: rebuild dev extension to rebuild the local dev extension. Only close the isolated test window when finished.

The bundled tree-sitter queries and pinned grammar reference are required resources; keep them alongside extension.toml. No source repository checkout or separately installed solar is needed.

Provenance and license

Migrated from paradigmxyz/solar's editors/zed at source revision bba703a34e0fabc8587ae7eb794e017e31c5e7ca. Original authorship is retained in extension.toml; the MIT and Apache-2.0 license files link to the repository root. The grammar remains pinned to JoranHonig/tree-sitter-solidity commit 048fe686cb1fde267243739b8bdbec8fc3a55272. Its MIT copyright notice is retained in GRAMMAR-LICENSE, including in local archives.

Foundry currently locks solar_lsp at 8d73a1e1fd53980a7f4ae020c821fb92f025616a. That revision already accepts forgePath, advertises document formatting, and delegates unsaved source to forge fmt --raw --root <project> -; this migration requires no dependency update. Future changes must check the revision in Foundry's Cargo.lock rather than assume that all newer Solar functionality is available.

Dual licensed under MIT or Apache-2.0. See LICENSE-MIT and LICENSE-APACHE.