1 files changed, 15 insertions, 1 deletions
diff --git a/libpanto-lua/src/module.zig b/libpanto-lua/src/module.zig
index f905765..8d07b42 100644
--- a/libpanto-lua/src/module.zig
+++ b/libpanto-lua/src/module.zig
@@ -356,9 +356,10 @@ fn registerMetatables(L: *c.lua_State) void {
     c.lua_settop(L, c.lua_gettop(L) - 1);
 
     if (c.luaL_newmetatable(L, STREAM_MT) != 0) {
-        c.lua_createtable(L, 0, 2); // methods
+        c.lua_createtable(L, 0, 3); // methods
         setMethod(L, "next", streamNext);
         setMethod(L, "events", streamEvents);
+        setMethod(L, "reopen", streamReopen);
         c.lua_setfield(L, -2, "__index");
         setMethod(L, "__gc", streamGc);
     }
@@ -1758,6 +1759,19 @@ fn streamIterStep(L_opt: ?*c.lua_State) callconv(.c) c_int {
     return 1;
 }
 
+/// `stream:reopen()`: reset a failed stream back to its turn-open boundary so
+/// the caller can resume `next()` after changing the agent config (e.g. catch
+/// a terminal error, swap the provider config via `agent:set_config(...)`, and
+/// retry the SAME turn without re-appending the user message). Errors if the
+/// stream has not failed (or is closed).
+fn streamReopen(L_opt: ?*c.lua_State) callconv(.c) c_int {
+    const L = L_opt.?;
+    const sbox = checkStream(L, 1);
+    if (sbox.closed) return luaErr(L, "panto: stream is closed");
+    sbox.stream.reopen() catch return luaErr(L, "panto: stream reopen failed");
+    return 0;
+}
+
 fn streamGc(L_opt: ?*c.lua_State) callconv(.c) c_int {
     const L = L_opt.?;
     const sbox = checkStream(L, 1);