Update docstrings for store classes (#2616)

This commit is contained in:
William FH
2024-12-03 19:51:25 -08:00
committed by GitHub
parent 584d9271ce
commit 5fa196ab38
13 changed files with 533 additions and 68 deletions
@@ -0,0 +1,123 @@
# How to add semantic search to your LangGraph deployment
This guide explains how to add semantic search to your LangGraph deployment's cross-thread [store](../../concepts/persistence.md#memory-store), so that your agent can search for memories and other documents by semantic similarity.
## Prerequisites
- A LangGraph deployment (see [how to deploy](setup_pyproject.md))
- API keys for your embedding provider (in this case, OpenAI)
- `langchain >= 0.3.8` (if you specify using the string format below)
## Steps
1. Update your `langgraph.json` configuration file to include the store configuration:
```json
{
...
"store": {
"index": {
"embed": "openai:text-embeddings-3-small",
"dims": 1536,
"fields": ["$"]
}
}
}
```
This configuration:
- Uses OpenAI's text-embeddings-3-small model for generating embeddings
- Sets the embedding dimension to 1536 (matching the model's output)
- Indexes all fields in your stored data (`["$"]` means index everything, or specify specific fields like `["text", "metadata.title"]`)
2. To use the string embedding format above, make sure your dependencies include `langchain >= 0.3.8`:
```toml
# In pyproject.toml
[project]
dependencies = [
"langchain>=0.3.8"
]
```
Or if using requirements.txt:
```
langchain>=0.3.8
```
## Usage
Once configured, you can use semantic search in your LangGraph nodes. The store requires a namespace tuple to organize memories:
```python
def search_memory(state: State, *, store: BaseStore):
# Search the store using semantic similarity
# The namespace tuple helps organize different types of memories
# e.g., ("user_facts", "preferences") or ("conversation", "summaries")
results = store.search(
namespace=("memory", "facts"), # Organize memories by type
query="your search query",
k=3 # number of results to return
)
return results
```
## Custom Embeddings
If you want to use custom embeddings, you can pass a path to a custom embedding function:
```json
{
...
"store": {
"index": {
"embed": "path/to/embedding_function.py:embed",
"dims": 1536,
"fields": ["$"]
}
}
}
```
The deployment will look for the function in the specified path. The function must be async and accept a list of strings:
```python
# path/to/embedding_function.py
from openai import AsyncOpenAI
client = AsyncOpenAI()
async def aembed_texts(texts: list[str]) -> list[list[float]]:
"""Custom embedding function that must:
1. Be async
2. Accept a list of strings
3. Return a list of float arrays (embeddings)
"""
response = await client.embeddings.create(
model="text-embedding-3-small",
input=texts
)
return [e.embedding for e in response.data]
```
## Querying via the API
You can also query the store using the LangGraph SDK. Since the SDK uses async operations:
```python
from langgraph_sdk import get_client
async def search_store():
client = get_client()
results = await client.store.search(
namespace=("memory", "facts"),
query="your search query",
limit=3 # number of results to return
)
return results
# Use in an async context
results = await search_store()
```
+24 -6
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@@ -171,7 +171,7 @@ trim_messages(
## Long-term memory
Long-term memory in LangGraph allows systems to retain information across different conversations or sessions. Unlike short-term memory, which is thread-scoped, long-term memory is saved within custom "namespaces."
Long-term memory in LangGraph allows systems to retain information across different conversations or sessions. Unlike short-term memory, which is **thread-scoped**, long-term memory is saved within custom "namespaces."
### Storing memories
@@ -180,16 +180,34 @@ LangGraph stores long-term memories as JSON documents in a [store](persistence.m
```python
from langgraph.store.memory import InMemoryStore
def embed(texts: list[str]) -> list[list[float]]:
# Replace with an actual embedding function or LangChain embeddings object
return [[1.0, 2.0] * len(texts)]
# InMemoryStore saves data to an in-memory dictionary. Use a DB-backed store in production use.
store = InMemoryStore()
store = InMemoryStore(index={"embed": embed, "dims": 2})
user_id = "my-user"
application_context = "chitchat"
namespace = (user_id, application_context)
store.put(namespace, "a-memory", {"rules": ["User likes short, direct language", "User only speaks English & python"], "my-key": "my-value"})
store.put(
namespace,
"a-memory",
{
"rules": [
"User likes short, direct language",
"User only speaks English & python",
],
"my-key": "my-value",
},
)
# get the "memory" by ID
item = store.get(namespace, "a-memory")
# list "memories" within this namespace, filtering on content equivalence
items = store.search(namespace, filter={"my-key": "my-value"})
# search for "memories" within this namespace, filtering on content equivalence, sorted by vector similarity
items = store.search(
namespace, filter={"my-key": "my-value"}, query="language preferences"
)
```
### Framework for thinking about long-term memory
@@ -232,7 +250,7 @@ Alternatively, memories can be a collection of documents that are continuously u
However, this shifts some complexity memory updating. The model must now _delete_ or _update_ existing items in the list, which can be tricky. In addition, some models may default to over-inserting and others may default to over-updating. See the [Trustcall](https://github.com/hinthornw/trustcall) package for one way to manage this and consider evaluation (e.g., with a tool like [LangSmith](https://docs.smith.langchain.com/tutorials/Developers/evaluation)) to help you tune the behavior.
Working with document collections also shifts complexity to memory **search** over the list. The `Store` currently supports [filtering by metadata](https://langchain-ai.github.io/langgraph/reference/store/#storage) and will soon add [semantic search shortly](https://python.langchain.com/docs/concepts/vectorstores/), but selecting the most relevant documents can be tricky as the list grows.
Working with document collections also shifts complexity to memory **search** over the list. The `Store` currently supports both [semantic search](https://langchain-ai.github.io/langgraph/reference/store/#langgraph.store.base.SearchOp.query) and [filtering by content](https://langchain-ai.github.io/langgraph/reference/store/#langgraph.store.base.SearchOp.filter).
Finally, using a collection of memories can make it challenging to provide comprehensive context to the model. While individual memories may follow a specific schema, this structure might not capture the full context or relationships between memories. As a result, when using these memories to generate responses, the model may lack important contextual information that would be more readily available in a unified profile approach.
@@ -41,6 +41,9 @@
" <p>\n",
" Support for the <code><a href=\"https://langchain-ai.github.io/langgraph/reference/store/#langgraph.store.base.BaseStore\">Store</a></code> API that is used in this guide was added in LangGraph <code>v0.2.32</code>.\n",
" </p>\n",
" <p>\n",
" Support for <b>index</b> and <b>query</b> arguments of the <code><a href=\"https://langchain-ai.github.io/langgraph/reference/store/#langgraph.store.base.BaseStore\">Store</a></code> API that is used in this guide was added in LangGraph <code>v0.2.54</code>.\n",
" </p>\n",
"</div>\n",
"\n",
"## Setup\n",
@@ -114,7 +117,7 @@
"\n",
"Importantly, to determine the user, we will be passing `user_id` via the config keyword argument of the node function.\n",
"\n",
"Let's first define an `InMemoryStore` which is already populated with some memories about the users."
"Let's first define an `InMemoryStore` already populated with some memories about the users."
]
},
{
@@ -125,8 +128,14 @@
"outputs": [],
"source": [
"from langgraph.store.memory import InMemoryStore\n",
"from langchain_openai import OpenAIEmbeddings\n",
"\n",
"in_memory_store = InMemoryStore()"
"in_memory_store = InMemoryStore(\n",
" index={\n",
" \"embed\": OpenAIEmbeddings(model=\"text-embedding-3-small\"),\n",
" \"dims\": 1536,\n",
" }\n",
")"
]
},
{
@@ -163,7 +172,7 @@
"def call_model(state: MessagesState, config: RunnableConfig, *, store: BaseStore):\n",
" user_id = config[\"configurable\"][\"user_id\"]\n",
" namespace = (\"memories\", user_id)\n",
" memories = store.search(namespace)\n",
" memories = store.search(namespace, query=str(state[\"messages\"][-1].content))\n",
" info = \"\\n\".join([d.value[\"data\"] for d in memories])\n",
" system_msg = f\"You are a helpful assistant talking to the user. User info: {info}\"\n",
"\n",
+2
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@@ -39,6 +39,7 @@ LangGraph makes it easy to manage conversation [memory](../concepts/memory.md) i
- [How to manage conversation history](memory/manage-conversation-history.ipynb)
- [How to delete messages](memory/delete-messages.ipynb)
- [How to add summary conversation memory](memory/add-summary-conversation-history.ipynb)
- [Add long-term memory (cross-thread)](cross-thread-persistence.ipynb)
### Human-in-the-loop
@@ -139,6 +140,7 @@ Learn how to set up your app for deployment to LangGraph Platform:
- [How to set up app for deployment (requirements.txt)](../cloud/deployment/setup.md)
- [How to set up app for deployment (pyproject.toml)](../cloud/deployment/setup_pyproject.md)
- [How to set up app for deployment (JavaScript)](../cloud/deployment/setup_javascript.md)
- [How to add semantic search](../cloud/deployment/semantic_search.md)
- [How to customize Dockerfile](../cloud/deployment/custom_docker.md)
- [How to test locally](../cloud/deployment/test_locally.md)
- [How to rebuild graph at runtime](../cloud/deployment/graph_rebuild.md)