diff --git a/providers/openrouter/models/stepfun/step-3.5-flash.toml b/providers/openrouter/models/stepfun/step-3.5-flash.toml
new file mode 100644
index 000000000..1845cea35
--- /dev/null
+++ b/providers/openrouter/models/stepfun/step-3.5-flash.toml
@@ -0,0 +1,30 @@
+name = "StepFun: Step 3.5 Flash"
+family = "step"
+release_date = "2026-01-29"
+last_updated = "2026-01-29"
+attachment = true
+reasoning = true
+temperature = true
+knowledge = "2025-01"
+tool_call = true
+structured_output = true
+open_weights = true
+
+[cost]
+input = 0.50
+output = 0.80
+
+[limit]
+context = 262_144
+input = 262_144
+output = 65_536
+
+[modalities]
+input = ["text", "image"]
+output = ["text"]
+
+[interleaved]
+field = "reasoning_content"
+
+[provider]
+npm = "@openrouter/ai-sdk-provider"