fix(llms,embeddings): honor TOGETHER_API_BASE for Together LLM and embedder

The Python Together LLM and embedder ignored TOGETHER_API_BASE, unlike
their TypeScript siblings, so users behind a gateway or proxy could not
redirect Together traffic. Add together_base_url to a new TogetherConfig
(LLM side) and to BaseEmbedderConfig (embedder side, matching the existing
openai_base_url/huggingface_base_url pattern), and resolve base_url with
explicit config value > TOGETHER_API_BASE env var > hardcoded default in
both mem0/llms/together.py and mem0/embeddings/together.py. Also register
TogetherConfig in LlmFactory.provider_to_class so config dicts routed
through Memory pick it up.

Closes #6587

tests/embeddings/test_together_embeddings.py

@@ -85,3 +85,29 @@ def test_explicit_config_overrides_defaults(mock_together_client):
     mock_together_client.embeddings.create.return_value = Mock(data=[Mock(embedding=[0.0] * 768)])
     embedder.embed("hello")
     mock_together_client.embeddings.create.assert_called_once_with(model="BAAI/bge-base-en-v1.5", input="hello")
+
+
+def test_together_embedding_base_url(monkeypatch):
+    # case1: default config uses Together's official base url
+    monkeypatch.delenv("TOGETHER_API_BASE", raising=False)
+    config = BaseEmbedderConfig(model=DEFAULT_MODEL, embedding_dims=DEFAULT_EMBEDDING_DIMS, api_key="api_key")
+    embedder = TogetherEmbedding(config)
+    assert str(embedder.client.base_url) == "https://api.together.ai/v1/"
+
+    # case2: with env variable TOGETHER_API_BASE
+    provider_base_url = "https://api.provider.com/v1/"
+    monkeypatch.setenv("TOGETHER_API_BASE", provider_base_url)
+    config = BaseEmbedderConfig(model=DEFAULT_MODEL, embedding_dims=DEFAULT_EMBEDDING_DIMS, api_key="api_key")
+    embedder = TogetherEmbedding(config)
+    assert str(embedder.client.base_url) == provider_base_url
+
+    # case3: with config.together_base_url (explicit config beats env var)
+    config_base_url = "https://api.config.com/v1/"
+    config = BaseEmbedderConfig(
+        model=DEFAULT_MODEL,
+        embedding_dims=DEFAULT_EMBEDDING_DIMS,
+        api_key="api_key",
+        together_base_url=config_base_url,
+    )
+    embedder = TogetherEmbedding(config)
+    assert str(embedder.client.base_url) == config_base_url

tests/llms/test_together.py

@@ -3,6 +3,7 @@ from unittest.mock import Mock, patch
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig
+from mem0.configs.llms.together import TogetherConfig
 from mem0.llms.together import TogetherLLM
 
 
@@ -14,6 +15,38 @@ def mock_together_client():
         yield mock_client
 
 
+def test_together_llm_base_url(monkeypatch):
+    # case1: default config uses Together's official base url
+    monkeypatch.delenv("TOGETHER_API_BASE", raising=False)
+    config = BaseLlmConfig(
+        model="mistralai/Mixtral-8x7B-Instruct-v0.1", temperature=0.7, max_tokens=100, top_p=1.0, api_key="api_key"
+    )
+    llm = TogetherLLM(config)
+    assert str(llm.client.base_url) == "https://api.together.ai/v1/"
+
+    # case2: with env variable TOGETHER_API_BASE
+    provider_base_url = "https://api.provider.com/v1/"
+    monkeypatch.setenv("TOGETHER_API_BASE", provider_base_url)
+    config = TogetherConfig(
+        model="mistralai/Mixtral-8x7B-Instruct-v0.1", temperature=0.7, max_tokens=100, top_p=1.0, api_key="api_key"
+    )
+    llm = TogetherLLM(config)
+    assert str(llm.client.base_url) == provider_base_url
+
+    # case3: with config.together_base_url (explicit config beats env var)
+    config_base_url = "https://api.config.com/v1/"
+    config = TogetherConfig(
+        model="mistralai/Mixtral-8x7B-Instruct-v0.1",
+        temperature=0.7,
+        max_tokens=100,
+        top_p=1.0,
+        api_key="api_key",
+        together_base_url=config_base_url,
+    )
+    llm = TogetherLLM(config)
+    assert str(llm.client.base_url) == config_base_url
+
+
 def test_generate_response_without_tools(mock_together_client):
     config = BaseLlmConfig(model="mistralai/Mixtral-8x7B-Instruct-v0.1", temperature=0.7, max_tokens=100, top_p=1.0)
     llm = TogetherLLM(config)