feat(lua-api): expose Typst path in Lua API

news/changelog-1.9.md

@@ -68,6 +68,10 @@ All changes included in 1.9:
 
 - ([#13414](https://github.com/quarto-dev/quarto-cli/issues/13414)): Be more forgiving when Confluence server returns malformed JSON response. (author: @m1no)
 
+## Lua API
+
+- ([#13762](https://github.com/quarto-dev/quarto-cli/issues/13762)): Add `quarto.paths.typst()` to Quarto's Lua API to resolve Typst binary path in Lua filters and extensions consistently with Quarto itself. (author: @mcanouil)
+
 ## Other fixes and improvements
 
 - ([#13402](https://github.com/quarto-dev/quarto-cli/issues/13402)): `nfpm` (<https://nfpm.goreleaser.com/>) is now used to create the `.deb` package, and new `.rpm` package. Both Linux packages are also now built for `x86_64` (`amd64`) and `aarch64` (`arm64`) architectures.

src/command/render/filters.ts

@@ -95,6 +95,7 @@ import { pythonExec } from "../../core/jupyter/exec.ts";
 import { kTocIndent } from "../../config/constants.ts";
 import { isWindows } from "../../deno_ral/platform.ts";
 import { tinyTexBinDir } from "../../tools/impl/tinytex-info.ts";
+import { typstBinaryPath } from "../../core/typst.ts";
 
 const kQuartoParams = "quarto-params";
 
@@ -204,6 +205,7 @@ async function quartoEnvironmentParams(_options: PandocOptions) {
     "paths": {
       "Rscript": await rBinaryPath("Rscript"),
       "TinyTexBinDir": tinyTexBinDir(), // will be undefined if no tinytex found and quarto will look in PATH
+      "Typst": typstBinaryPath(),
     },
   };
 }

src/resources/lua-types/quarto/paths.lua

@@ -13,3 +13,11 @@ Returns the path to the `TinyTeX` bin directory that `quarto install tinytex` in
 ]]
 ---@return string|nil # Path to `TinyTeX` bin directory
 function quarto.paths.tinytex_bin_dir() end
+
+--[[
+Returns the path to the Typst binary that Quarto itself would use for rendering Typst documents.
+This will be the value of the QUARTO_TYPST environment variable if set, or the path to the
+Typst binary bundled with Quarto.
+]]
+---@return string # Path to Typst binary
+function quarto.paths.typst() end

src/resources/pandoc/datadir/init.lua

@@ -990,6 +990,9 @@ quarto = {
     tinytex_bin_dir = function()
       return param('quarto-environment', nil).paths.TinyTexBinDir
     end,
+    typst = function()
+      return param('quarto-environment', nil).paths.Typst
+    end,
   },
   json = json,
   base64 = base64,

tests/docs/smoke-all/2025/12/05/typst-path-api.lua

@@ -0,0 +1,5 @@
+function Pandoc(doc)
+  if quarto.paths.typst() == nil then
+    crash()
+  end
+end

tests/docs/smoke-all/2025/12/05/typst-path-api.qmd

@@ -0,0 +1,7 @@
+---
+format: html
+filters:
+  - typst-path-api.lua
+---
+
+The Typst path is accessible.