diff --git a/PLAN.md b/PLAN.md
index f2f3303..48f0854 100644
--- a/PLAN.md
+++ b/PLAN.md
@@ -78,9 +78,11 @@ instance without any client support. N sessions then spread across hosts by
 free slots × weight *at start* and are held there; the per-(host, model) queue
 (§6) is what stops N from oversubscribing any one host.
 
-Client launcher (OpenCode config substitutes `{env:VAR}` in values — verify on
-the installed build; if absent, the same value goes through
-`options.headers["X-Crossbar-Route"]`, which crossbar also accepts):
+Client launcher (OpenCode config substitutes `{env:VAR}` in values — verified
+in the installed 1.15.10 bundle: `/\{env:([^}]+)\}/g` → `process.env[V]`,
+missing → empty string, so always set the variable; as a fallback the same
+value can go through `options.headers["X-Crossbar-Route"]`, which crossbar
+also accepts):
 
 ```jsonc
 // ~/.config/opencode/opencode.json (one block for every project)