docs: add Synap memory provider page

[Anish Yadav (visy-ani)]

Summary

Adds a provider page for Synap under src/oss/integrations/providers/synap.mdx, matching the existing cala.mdx format.

Synap is a managed long-term memory layer for AI agents. The synap-langchain package provides five LangChain surfaces (chat history, retriever, agent tools, callback handler, LangGraph node).

• PyPI: https://pypi.org/project/synap-langchain/
• Open source: https://github.com/maximem-ai/maximem_synap_sdk/tree/main/packages/integrations/synap-langchain

[github-actions]

Thanks for opening a docs PR, Anish Yadav (@visy-ani)! When it's ready for review, please add the relevant reviewers:

• @npentrel or @lnhsingh (open source)

[Copilot]

Pull request overview

Adds a new Synap provider documentation page under the OSS integrations docs, describing Synap’s “long-term memory” offering and showing example usage across multiple LangChain/LangGraph integration surfaces.

Changes:

• Adds a new synap.mdx provider page with installation/configuration guidance.
• Documents five Synap “integration surfaces” (chat history, retriever, agent tools, callbacks, LangGraph node) with Python snippets.
• Adds scoping and resource links for Synap.

Comments suppressed due to low confidence (2)

src/oss/integrations/providers/synap.mdx:90

• This agent snippet references llm and prompt without defining them, so it won’t run as-is. Consider adding minimal setup (or an explicit placeholder comment) so the snippet is copy/pasteable.

    SynapSearchTool(sdk=sdk, user_id="alice", customer_id="acme_corp"),
    SynapStoreTool(sdk=sdk, user_id="alice", customer_id="acme_corp"),
]
agent = create_tool_calling_agent(llm, tools, prompt)
executor = AgentExecutor(agent=agent, tools=tools)

src/oss/integrations/providers/synap.mdx:113

• The LangGraph snippet references MyState without defining it. If it’s a placeholder, call that out explicitly (or include a minimal state definition) so readers can adapt the example quickly.

graph = StateGraph(MyState)
graph.add_node("memory", create_synap_node(sdk, user_id="alice"))

[Anish Yadav (visy-ani)]

Hi Mukil Loganathan (@langchain-infra) and Kathryn May (@katmayb) 👋 — would love a review on this whenever you have a moment! This adds src/oss/integrations/providers/synap.mdx (matching the existing cala.mdx format) plus a Card entry in the Python all_providers.mdx index.

Why this is useful: synap-langchain provides five LangChain surfaces in one package — SynapChatMessageHistory, SynapRetriever, SynapSearchTool / SynapStoreTool, SynapCallbackHandler, and create_synap_node (for LangGraph). The provider page is the canonical home so users can discover the package and the right surface for their chain.

I addressed Copilot's review feedback in the latest push: added YAML frontmatter, made the chat history example self-contained (chain is now fully defined with ChatPromptTemplate + ChatOpenAI), passed customer_id to create_synap_node for consistency with the scoping note, and added the provider to all_providers.mdx. All tests, lint, links, and cross-refs are passing. Thanks!