feat(volcengine): add the Seed 2.1 flagship models

litellm/model_prices_and_context_window_backup.json

@@ -50139,6 +50139,36 @@
             }
         ]
     },
+    "volcengine/doubao-seed-2-1-pro-260628": {
+        "cache_read_input_token_cost": 1.78120508023e-07,
+        "input_cost_per_token": 8.90602540117e-07,
+        "litellm_provider": "volcengine",
+        "max_input_tokens": 256000,
+        "max_output_tokens": 256000,
+        "max_tokens": 256000,
+        "mode": "chat",
+        "output_cost_per_token": 4.45301270059e-06,
+        "source": "https://www.volcengine.com/docs/82379/1330310",
+        "supports_function_calling": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": false,
+        "supports_vision": true
+    },
+    "volcengine/doubao-seed-2-1-turbo-260628": {
+        "cache_read_input_token_cost": 8.90602540117e-08,
+        "input_cost_per_token": 4.45301270059e-07,
+        "litellm_provider": "volcengine",
+        "max_input_tokens": 256000,
+        "max_output_tokens": 256000,
+        "max_tokens": 256000,
+        "mode": "chat",
+        "output_cost_per_token": 2.22650635029e-06,
+        "source": "https://www.volcengine.com/docs/82379/1330310",
+        "supports_function_calling": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": false,
+        "supports_vision": true
+    },
     "bedrock/us-east-1/zai.glm-5": {
         "input_cost_per_token": 1e-06,
         "output_cost_per_token": 3.2e-06,

model_prices_and_context_window.json

@@ -50139,6 +50139,36 @@
             }
         ]
     },
+    "volcengine/doubao-seed-2-1-pro-260628": {
+        "cache_read_input_token_cost": 1.78120508023e-07,
+        "input_cost_per_token": 8.90602540117e-07,
+        "litellm_provider": "volcengine",
+        "max_input_tokens": 256000,
+        "max_output_tokens": 256000,
+        "max_tokens": 256000,
+        "mode": "chat",
+        "output_cost_per_token": 4.45301270059e-06,
+        "source": "https://www.volcengine.com/docs/82379/1330310",
+        "supports_function_calling": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": false,
+        "supports_vision": true
+    },
+    "volcengine/doubao-seed-2-1-turbo-260628": {
+        "cache_read_input_token_cost": 8.90602540117e-08,
+        "input_cost_per_token": 4.45301270059e-07,
+        "litellm_provider": "volcengine",
+        "max_input_tokens": 256000,
+        "max_output_tokens": 256000,
+        "max_tokens": 256000,
+        "mode": "chat",
+        "output_cost_per_token": 2.22650635029e-06,
+        "source": "https://www.volcengine.com/docs/82379/1330310",
+        "supports_function_calling": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": false,
+        "supports_vision": true
+    },
     "bedrock/us-east-1/zai.glm-5": {
         "input_cost_per_token": 1e-06,
         "output_cost_per_token": 3.2e-06,

tests/test_litellm/llms/volcengine/test_volcengine_model_catalog.py

@@ -0,0 +1,74 @@
+"""
+Tests for the Volcengine Ark model catalog entries.
+
+These assert the properties that were checked against the live Ark API
+(POST https://ark.cn-beijing.volces.com/api/v3/chat/completions) so a future
+edit cannot silently contradict them.
+"""
+
+import pytest
+
+from litellm import get_model_info
+
+
+SEED_2_1_FLAGSHIPS = [
+    "volcengine/doubao-seed-2-1-pro-260628",
+    "volcengine/doubao-seed-2-1-turbo-260628",
+]
+
+
+@pytest.mark.parametrize("model", SEED_2_1_FLAGSHIPS)
+def test_seed_2_1_flagship_is_registered(model):
+    """Both flagships must resolve through get_model_info with the volcengine provider."""
+    info = get_model_info(model=model)
+    assert info["litellm_provider"] == "volcengine"
+    assert info["mode"] == "chat"
+
+
+@pytest.mark.parametrize("model", SEED_2_1_FLAGSHIPS)
+def test_seed_2_1_flagship_limits(model):
+    """Ark documents 256k context and 256k max output for both models.
+
+    The 256k output ceiling was also probed directly: max_tokens=256000 is
+    accepted and 300000 is rejected with "max_tokens ... not valid".
+    """
+    info = get_model_info(model=model)
+    assert info["max_input_tokens"] == 256000
+    assert info["max_output_tokens"] == 256000
+
+
+@pytest.mark.parametrize("model", SEED_2_1_FLAGSHIPS)
+def test_seed_2_1_flagship_capabilities(model):
+    """Reasoning, vision and function calling were each confirmed against the API.
+
+    supports_tool_choice stays False, matching the other volcengine entries:
+    a forced function is honoured, but tool_choice="none" is ignored and the
+    model calls the tool anyway, so the parameter is not fully supported.
+    """
+    info = get_model_info(model=model)
+    assert info["supports_reasoning"] is True
+    assert info["supports_vision"] is True
+    assert info["supports_function_calling"] is True
+    assert info["supports_tool_choice"] is False
+
+
+def test_seed_2_1_pro_is_priced_above_turbo():
+    """Ark lists pro at CNY 6/30 per 1M and turbo at CNY 3/15, i.e. turbo is half.
+
+    Asserting the ratio rather than absolute figures keeps the test meaningful
+    if the CNY-to-USD rate is refreshed later.
+    """
+    pro = get_model_info(model="volcengine/doubao-seed-2-1-pro-260628")
+    turbo = get_model_info(model="volcengine/doubao-seed-2-1-turbo-260628")
+
+    assert pro["input_cost_per_token"] == pytest.approx(
+        turbo["input_cost_per_token"] * 2, rel=1e-6
+    )
+    assert pro["output_cost_per_token"] == pytest.approx(
+        turbo["output_cost_per_token"] * 2, rel=1e-6
+    )
+    # cache-hit pricing is a fifth of the input price on both
+    for info in (pro, turbo):
+        assert info["cache_read_input_token_cost"] == pytest.approx(
+            info["input_cost_per_token"] / 5, rel=1e-6
+        )