diff --git a/packages/opencode/src/tool/registry.ts b/packages/opencode/src/tool/registry.ts
index 2c862dfd8..7b3a45889 100644
--- a/packages/opencode/src/tool/registry.ts
+++ b/packages/opencode/src/tool/registry.ts
@@ -67,7 +67,11 @@ export namespace ToolRegistry {
         parameters: z.object(def.args),
         description: def.description,
         execute: async (args, ctx) => {
-          const pluginCtx = { ...ctx, directory: Instance.directory } as unknown as PluginToolContext
+          const pluginCtx = {
+            ...ctx,
+            directory: Instance.directory,
+            worktree: Instance.worktree,
+          } as unknown as PluginToolContext
           const result = await def.execute(args as any, pluginCtx)
           const out = await Truncate.output(result, {}, initCtx?.agent)
           return {
diff --git a/packages/plugin/src/tool.ts b/packages/plugin/src/tool.ts
index 6b4f7f1d1..23aa512d9 100644
--- a/packages/plugin/src/tool.ts
+++ b/packages/plugin/src/tool.ts
@@ -9,6 +9,11 @@ export type ToolContext = {
    * Prefer this over process.cwd() when resolving relative paths.
    */
   directory: string
+  /**
+   * Project worktree root for this session.
+   * Useful for generating stable relative paths (e.g. path.relative(worktree, absPath)).
+   */
+  worktree: string
   abort: AbortSignal
   metadata(input: { title?: string; metadata?: { [key: string]: any } }): void
   ask(input: AskInput): Promise<void>