diff --git a/clawdforge/server.py b/clawdforge/server.py
index 1836ed2..eaa876d 100644
--- a/clawdforge/server.py
+++ b/clawdforge/server.py
@@ -129,7 +129,11 @@ class RunRequest(BaseModel):
     # get the budget they deserve.
     effort: Literal["low", "medium", "high", "xhigh", "max"] | None = None
     files: list[str] | None = None
-    timeout_secs: int | None = Field(default=None, ge=5, le=600)
+    # Long-form prose-craft at --effort max can run 10–20 min wall clock,
+    # so the per-run cap is 1800s. Server still streams a per-process
+    # SIGTERM at the boundary; the caller's RunResult.duration_ms is
+    # honest about wall clock.
+    timeout_secs: int | None = Field(default=None, ge=5, le=1800)
 
 
 class TokenCreateRequest(BaseModel):