Files
langchain/libs/partners/ollama/langchain_ollama/embeddings.py
Alexey Bondarenko 9efafe3337 ollama: Add separate kwargs parameter for async client (#31209)
**Description**:

Add a `async_client_kwargs` field to ollama chat/llm/embeddings adapters
that is passed to async httpx client constructor.

**Motivation:**

In my use-case:
- chat/embedding model adapters may be created frequently, sometimes to
be called just once or to never be called at all
- they may be used in bots sunc and async mode (not known at the moment
they are created)

So, I want to keep a static transport instance maintaining connection
pool, so model adapters can be created and destroyed freely. But that
doesn't work when both sync and async functions are in use as I can only
pass one transport instance for both sync and async client, while
transport types must be different for them. So I can't make both sync
and async calls use shared transport with current model adapter
interfaces.

In this PR I add a separate `async_client_kwargs` that gets passed to
async client constructor, so it will be possible to pass a separate
transport instance. For sake of backwards compatibility, it is merged
with `client_kwargs`, so nothing changes when it is not set.

I am unable to run linter right now, but the changes look ok.
2025-05-15 16:10:10 -04:00

286 lines
9.3 KiB
Python

"""Ollama embeddings models."""
from typing import Any, Optional
from langchain_core.embeddings import Embeddings
from ollama import AsyncClient, Client
from pydantic import (
BaseModel,
ConfigDict,
PrivateAttr,
model_validator,
)
from typing_extensions import Self
class OllamaEmbeddings(BaseModel, Embeddings):
"""Ollama embedding model integration.
Set up a local Ollama instance:
Install the Ollama package and set up a local Ollama instance
using the instructions here: https://github.com/ollama/ollama .
You will need to choose a model to serve.
You can view a list of available models via the model library (https://ollama.com/library).
To fetch a model from the Ollama model library use ``ollama pull <name-of-model>``.
For example, to pull the llama3 model:
.. code-block:: bash
ollama pull llama3
This will download the default tagged version of the model.
Typically, the default points to the latest, smallest sized-parameter model.
* On Mac, the models will be downloaded to ~/.ollama/models
* On Linux (or WSL), the models will be stored at /usr/share/ollama/.ollama/models
You can specify the exact version of the model of interest
as such ``ollama pull vicuna:13b-v1.5-16k-q4_0``.
To view pulled models:
.. code-block:: bash
ollama list
To start serving:
.. code-block:: bash
ollama serve
View the Ollama documentation for more commands.
.. code-block:: bash
ollama help
Install the langchain-ollama integration package:
.. code-block:: bash
pip install -U langchain_ollama
Key init args — completion params:
model: str
Name of Ollama model to use.
base_url: Optional[str]
Base url the model is hosted under.
See full list of supported init args and their descriptions in the params section.
Instantiate:
.. code-block:: python
from langchain_ollama import OllamaEmbeddings
embed = OllamaEmbeddings(
model="llama3"
)
Embed single text:
.. code-block:: python
input_text = "The meaning of life is 42"
vector = embed.embed_query(input_text)
print(vector[:3])
.. code-block:: python
[-0.024603435769677162, -0.007543657906353474, 0.0039630369283258915]
Embed multiple texts:
.. code-block:: python
input_texts = ["Document 1...", "Document 2..."]
vectors = embed.embed_documents(input_texts)
print(len(vectors))
# The first 3 coordinates for the first vector
print(vectors[0][:3])
.. code-block:: python
2
[-0.024603435769677162, -0.007543657906353474, 0.0039630369283258915]
Async:
.. code-block:: python
vector = await embed.aembed_query(input_text)
print(vector[:3])
# multiple:
# await embed.aembed_documents(input_texts)
.. code-block:: python
[-0.009100092574954033, 0.005071679595857859, -0.0029193938244134188]
""" # noqa: E501
model: str
"""Model name to use."""
base_url: Optional[str] = None
"""Base url the model is hosted under."""
client_kwargs: Optional[dict] = {}
"""Additional kwargs to pass to the httpx clients.
These arguments are passed to both synchronous and async clients.
Use sync_client_kwargs and async_client_kwargs to pass different arguments
to synchronous and asynchronous clients.
"""
async_client_kwargs: Optional[dict] = {}
"""Additional kwargs to merge with client_kwargs before
passing to the httpx AsyncClient.
For a full list of the params, see [this link](https://www.python-httpx.org/api/#asyncclient)
"""
sync_client_kwargs: Optional[dict] = {}
"""Additional kwargs to merge with client_kwargs before
passing to the httpx Client.
For a full list of the params, see [this link](https://www.python-httpx.org/api/#client)
"""
_client: Client = PrivateAttr(default=None) # type: ignore
"""
The client to use for making requests.
"""
_async_client: AsyncClient = PrivateAttr(default=None) # type: ignore
"""
The async client to use for making requests.
"""
mirostat: Optional[int] = None
"""Enable Mirostat sampling for controlling perplexity.
(default: 0, 0 = disabled, 1 = Mirostat, 2 = Mirostat 2.0)"""
mirostat_eta: Optional[float] = None
"""Influences how quickly the algorithm responds to feedback
from the generated text. A lower learning rate will result in
slower adjustments, while a higher learning rate will make
the algorithm more responsive. (Default: 0.1)"""
mirostat_tau: Optional[float] = None
"""Controls the balance between coherence and diversity
of the output. A lower value will result in more focused and
coherent text. (Default: 5.0)"""
num_ctx: Optional[int] = None
"""Sets the size of the context window used to generate the
next token. (Default: 2048) """
num_gpu: Optional[int] = None
"""The number of GPUs to use. On macOS it defaults to 1 to
enable metal support, 0 to disable."""
keep_alive: Optional[int] = None
"""controls how long the model will stay loaded into memory
following the request (default: 5m)
"""
num_thread: Optional[int] = None
"""Sets the number of threads to use during computation.
By default, Ollama will detect this for optimal performance.
It is recommended to set this value to the number of physical
CPU cores your system has (as opposed to the logical number of cores)."""
repeat_last_n: Optional[int] = None
"""Sets how far back for the model to look back to prevent
repetition. (Default: 64, 0 = disabled, -1 = num_ctx)"""
repeat_penalty: Optional[float] = None
"""Sets how strongly to penalize repetitions. A higher value (e.g., 1.5)
will penalize repetitions more strongly, while a lower value (e.g., 0.9)
will be more lenient. (Default: 1.1)"""
temperature: Optional[float] = None
"""The temperature of the model. Increasing the temperature will
make the model answer more creatively. (Default: 0.8)"""
stop: Optional[list[str]] = None
"""Sets the stop tokens to use."""
tfs_z: Optional[float] = None
"""Tail free sampling is used to reduce the impact of less probable
tokens from the output. A higher value (e.g., 2.0) will reduce the
impact more, while a value of 1.0 disables this setting. (default: 1)"""
top_k: Optional[int] = None
"""Reduces the probability of generating nonsense. A higher value (e.g. 100)
will give more diverse answers, while a lower value (e.g. 10)
will be more conservative. (Default: 40)"""
top_p: Optional[float] = None
"""Works together with top-k. A higher value (e.g., 0.95) will lead
to more diverse text, while a lower value (e.g., 0.5) will
generate more focused and conservative text. (Default: 0.9)"""
model_config = ConfigDict(
extra="forbid",
)
@property
def _default_params(self) -> dict[str, Any]:
"""Get the default parameters for calling Ollama."""
return {
"mirostat": self.mirostat,
"mirostat_eta": self.mirostat_eta,
"mirostat_tau": self.mirostat_tau,
"num_ctx": self.num_ctx,
"num_gpu": self.num_gpu,
"num_thread": self.num_thread,
"repeat_last_n": self.repeat_last_n,
"repeat_penalty": self.repeat_penalty,
"temperature": self.temperature,
"stop": self.stop,
"tfs_z": self.tfs_z,
"top_k": self.top_k,
"top_p": self.top_p,
}
@model_validator(mode="after")
def _set_clients(self) -> Self:
"""Set clients to use for ollama."""
client_kwargs = self.client_kwargs or {}
sync_client_kwargs = client_kwargs
if self.sync_client_kwargs:
sync_client_kwargs = {**sync_client_kwargs, **self.sync_client_kwargs}
async_client_kwargs = client_kwargs
if self.async_client_kwargs:
async_client_kwargs = {**async_client_kwargs, **self.async_client_kwargs}
self._client = Client(host=self.base_url, **sync_client_kwargs)
self._async_client = AsyncClient(host=self.base_url, **async_client_kwargs)
return self
def embed_documents(self, texts: list[str]) -> list[list[float]]:
"""Embed search docs."""
embedded_docs = self._client.embed(
self.model, texts, options=self._default_params, keep_alive=self.keep_alive
)["embeddings"]
return embedded_docs
def embed_query(self, text: str) -> list[float]:
"""Embed query text."""
return self.embed_documents([text])[0]
async def aembed_documents(self, texts: list[str]) -> list[list[float]]:
"""Embed search docs."""
embedded_docs = (
await self._async_client.embed(
self.model, texts, keep_alive=self.keep_alive
)
)["embeddings"]
return embedded_docs
async def aembed_query(self, text: str) -> list[float]:
"""Embed query text."""
return (await self.aembed_documents([text]))[0]