[Memory] Add DakeraMemoryService — persistent, decay-weighted cross-session memory

[ferhimedamine]

Summary

This issue proposes adding DakeraMemoryService, a new implementation of BaseMemoryService backed by a self-hosted Dakera server.

Motivation

The existing InMemoryMemoryService is an excellent starting point for development, but memories are discarded on process restart and do not scale beyond a single process. VertexAiMemoryBankService and VertexAiRagMemoryService cover the managed-cloud use case, but a growing number of ADK users need persistent, self-hosted memory without a dependency on Google Cloud.

Dakera is an open-deployment vector memory server that provides:

• Semantic search over stored memories via a built-in HNSW vector index and embedding model.
• Decay-weighted importance — memories that have not been accessed recently receive lower recall scores, mirroring how human memory fades.
• Cross-session persistence — memories survive process restarts and can be shared across multiple agent instances.
• Zero external-cloud dependency — the server runs as a single Docker container or binary on any Linux host.

Proposed API

from google.adk.memory import DakeraMemoryService

memory_service = DakeraMemoryService(
    base_url="http://localhost:3000",  # or DAKERA_API_URL env var
    api_key="sk-...",                  # or DAKERA_API_KEY env var
    top_k=10,
)

Plug it into any ADK Runner that accepts a memory_service parameter:

from google.adk.runners import Runner

runner = Runner(
    agent=my_agent,
    app_name="my_app",
    session_service=session_service,
    memory_service=memory_service,
)

Implementation plan

• src/google/adk/memory/dakera_memory_service.py — DakeraMemoryService(BaseMemoryService) using httpx.AsyncClient
  • add_session_to_memory(session) → POST /v1/memories per event
  • search_memory(app_name, user_id, query) → POST /v1/memories/search → SearchMemoryResponse
• src/google/adk/memory/__init__.py — lazy-import export alongside existing services
• tests/unittests/memory/test_dakera_memory_service.py — unit tests with httpx mock transport

Self-hosting

docker run -p 3000:3000 dakera/dakera:latest

Full deployment guide: https://dakera.ai

Related

• BaseMemoryService ABC in src/google/adk/memory/base_memory_service.py
• InMemoryMemoryService — in-process reference implementation