diff --git a/src/hooks/usePantry.ts b/src/hooks/usePantry.ts
index 64a1cf23..69ab8bb2 100644
--- a/src/hooks/usePantry.ts
+++ b/src/hooks/usePantry.ts
@@ -11,9 +11,14 @@ interface Response {
   /// returns sorted versions
   getVersions(rq: PackageRequirement | Package): Promise<SemVer[]>
   getDeps(pkg: Package | PackageRequirement): Promise<{ runtime: PackageRequirement[], build: PackageRequirement[] }>
-  getBuildScript(pkg: Package): Promise<string>
+  getScript(pkg: Package, key: 'build' | 'test'): Promise<string>
   update(): Promise<void>
   getProvides(rq: PackageRequirement | Package): Promise<string[]>
+
+  //TODO take `T` and then type check it
+  getYAML(rq: PackageRequirement | Package): Promise<[PlainObject, Path]>
+
+  prefix(rq: PackageRequirement | Package): Path
 }
 
 interface Entry {
@@ -79,6 +84,12 @@ export default function usePantry(): Response {
     }
   }
 
+  const getYAML = async (pkg: Package | PackageRequirement): Promise<[PlainObject, Path]> => {
+    const foo = entry(pkg)
+    const yml = await foo.yml()
+    return [yml, foo.dir.join("package.yml")]
+  }
+
   const getDeps = async (pkg: Package | PackageRequirement) => {
     const yml =  await entry(pkg).yml()
     return {
@@ -114,12 +125,15 @@ export default function usePantry(): Response {
     return { url, stripComponents }
   }
 
-  const getBuildScript = async (pkg: Package) => {
+  const getScript = async (pkg: Package, key: 'build' | 'test') => {
     const yml = await entry(pkg).yml()
-    let raw = validateString(validatePlainObject(yml.build).script)
+    const obj = validatePlainObject(yml[key])
 
-    const wd = yml.build["working-directory"]
+    let raw = validateString(obj.script)
+
+    let wd = obj["working-directory"]
     if (wd) {
+      wd = remapTokens(wd, pkg)
       raw = undent`
         mkdir -p ${wd}
         cd ${wd}
@@ -128,7 +142,7 @@ export default function usePantry(): Response {
         `
     }
 
-    const env = yml.build.env
+    const env = obj.env
     if (isPlainObject(env)) {
       const expanded_env = Object.entries(env).map(([key,value]) => {
         if (isArray(value)) {
@@ -179,7 +193,8 @@ export default function usePantry(): Response {
       { from: "hw.target", to: platform.target },
       { from: "hw.platform", to: platform.platform },
       { from: "prefix", to: prefix.string },
-      { from: "hw.concurrency", to: navigator.hardwareConcurrency.toString() }
+      { from: "hw.concurrency", to: navigator.hardwareConcurrency.toString() },
+      { from: "pkg.pantry-prefix", to: getPrefix(pkg).string }
     ].reduce((acc, map) => acc.replace(new RegExp(`\\$?{{\\s*${map.from}\\s*}}`, "g"), map.to), input)
   }
 
@@ -204,7 +219,12 @@ export default function usePantry(): Response {
     })
   }
 
-  return { getVersions, getDeps, getDistributable, getBuildScript, update, getProvides }
+  const getPrefix = (pkg: Package | PackageRequirement) => prefix.join(pkg.project)
+
+  return { getVersions, getDeps, getDistributable, getScript, update, getProvides,
+    getYAML,
+    prefix: getPrefix
+  }
 }
 
 
diff --git a/src/hooks/useShellEnv.ts b/src/hooks/useShellEnv.ts
index ffe4b64f..401f9aae 100644
--- a/src/hooks/useShellEnv.ts
+++ b/src/hooks/useShellEnv.ts
@@ -90,3 +90,12 @@ function suffixes(key: string) {
       throw new Error("unhandled")
   }
 }
+
+export function expand(env: Record<string, string[]>) {
+  let rv = ''
+  for (let [key, value] of Object.entries(env)) {
+    if (key == 'PATH') value = value.concat("/usr/bin:/bin:/usr/sbin:/sbin") //FIXME
+    rv += `export ${key}='${value.join(":")}'\n`
+  }
+  return rv
+}
\ No newline at end of file
diff --git a/src/prefab/build.ts b/src/prefab/build.ts
index 0bc4e59d..52dd3952 100644
--- a/src/prefab/build.ts
+++ b/src/prefab/build.ts
@@ -1,7 +1,7 @@
 import { Path, Package, PackageRequirement, semver } from "types"
 import usePantry from "hooks/usePantry.ts"
 import useCellar from "hooks/useCellar.ts"
-import useShellEnv from "hooks/useShellEnv.ts"
+import useShellEnv, { expand } from "hooks/useShellEnv.ts"
 import { run, undent } from "utils"
 import usePlatform from "hooks/usePlatform.ts"
 import hydrate from "prefab/hydrate.ts"
@@ -22,7 +22,7 @@ export default async function build({ pkg, deps, prebuild }: Options): Promise<P
   const src = dst.join("src")
   const runtime_deps = await filterAndHydrate(deps.runtime)
   const env = await useShellEnv([...deps.build, ...runtime_deps])
-  const sh = await pantry.getBuildScript(pkg)
+  const sh = await pantry.getScript(pkg, 'build')
   const { platform } = usePlatform()
 
   if (env.pending.length) {
@@ -78,15 +78,6 @@ async function filterAndHydrate(pkgs: PackageRequirement[]): Promise<PackageRequ
   }
 }
 
-function expand(env: Record<string, string[]>) {
-  let rv = ''
-  for (let [key, value] of Object.entries(env)) {
-    if (key == 'PATH') value = value.concat("/usr/bin:/bin:/usr/sbin:/sbin") //FIXME
-    rv += `export ${key}='${value.join(":")}'\n`
-  }
-  return rv
-}
-
 async function* exefiles(prefix: Path) {
   for (const basename of ["bin", "lib"]) { //TODO the rest
     const d = prefix.join(basename).isDirectory()
diff --git a/src/types.ts b/src/types.ts
index 9c5b95fe..7605500c 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -54,6 +54,18 @@ export function parsePackageRequirement(input: string): PackageRequirement {
   }
 }
 
+export function parsePackage(input: string): Package {
+  const splat = input.split('@') //FIXME we do specs with eg. foo^1
+  if (splat.length == 2) {
+    return {
+      project: splat[0],
+      version: new SemVer(splat[1])
+    }
+  } else {
+    throw "invalid-pkgspec"
+  }
+}
+
 /////////////////////////////////////////////////////////////////////// semver
 import SemVer, * as semver from "semver"