Backends

ADK stores are implemented per adapter. Each backend has different capabilities for session, event, memory, and artifact storage. Use the support matrix below to select the right backend for your deployment.

Support Matrix

The table below classifies every backend by its ADK support level.

Adapter	Status	Session/Event	Memory (FTS)	Artifacts	Notes
asyncpg	Recommended	Full	Full	Full	Best async PostgreSQL driver.
psycopg (async)	Recommended	Full	Full	Full	Supports both sync and async modes.
psqlpy	Supported	Full	Full	Full	Rust-backed PostgreSQL driver.
cockroach_asyncpg	Supported	Full	Full	Full	CockroachDB with full FTS support.
cockroach_psycopg	Supported	Full	Full	Full	CockroachDB with full FTS support.
asyncmy	Supported	Full	Full	Full	MySQL/MariaDB async driver.
mysqlconnector	Supported	Full	Full	Full	MySQL/MariaDB sync driver.
pymysql	Supported	Full	Full	Full	MySQL/MariaDB sync driver.
aiosqlite	Supported	Full	Full	Full	SQLite async, ideal for development.
sqlite	Supported	Full	Full	Full	SQLite sync with thread-local pools.
oracledb	Supported	Full	Full	Full	Oracle Database driver.
duckdb	Reduced-scope	Full	Limited	Full	Analytics-oriented; no concurrent writes.
adbc	Supported	Full	Full	Full	Arrow-native database connectivity.
spanner	Supported	Full	Full	Full	Google Cloud Spanner (cloud-managed).

Status Definitions

Recommended

Production-grade, fully tested, actively optimized. Start here unless you have a specific reason not to.

Supported

Fully implemented and tested. Works correctly for all ADK operations.

Reduced-scope

Implemented with known limitations. Specific features may be absent or behave differently. See backend-specific notes.

Removed

Previously available but no longer supported. See the removal notice for migration guidance.

Removed Backends

BigQuery was removed from the ADK backend surface. BigQuery's batch-oriented architecture is incompatible with the low-latency, transactional write patterns that ADK session and event storage require. If you were using BigQuery for ADK storage, migrate to PostgreSQL (asyncpg or psycopg) or any other supported backend.

Backend Details

PostgreSQL Family

PostgreSQL backends (asyncpg, psycopg, psqlpy) provide the fullest feature set:

• Native JSONB storage for session state and event JSON.

• Full-text search via tsvector for memory entries.

• UPSERT and RETURNING clauses for atomic operations.

• append_event_and_update_state() executes as a single transaction.

Recommended for production deployments.

CockroachDB

CockroachDB backends (cockroach_asyncpg, cockroach_psycopg) provide full ADK support including full-text search. CockroachDB is a distributed SQL database compatible with the PostgreSQL wire protocol.

• Full FTS support for memory search.

• Distributed transactions for session and event atomicity.

• Horizontal scalability for high-throughput agent deployments.

MySQL Family

MySQL backends (asyncmy, mysqlconnector, pymysql) provide full ADK support:

• JSON column storage for session state and event records.

• Full-text search on InnoDB tables for memory entries.

• Transactional writes for append_event_and_update_state().

SQLite

SQLite backends (aiosqlite, sqlite) are ideal for local development, testing, and single-process deployments:

• JSON1 extension for state and event storage.

• FTS5 virtual tables for memory full-text search.

• File-based or in-memory operation.

Note

SQLite does not support concurrent writers. Use a server-backed database for production multi-process deployments.

Oracle

Oracle Database (oracledb) provides full ADK support:

• Native JSON column support (Oracle 21c+).

• Oracle Text for full-text search on memory entries.

• Full transactional support for atomic operations.

DuckDB

DuckDB provides session and event storage but has limitations:

• Optimized for analytics, not OLTP workloads.

• Single-writer constraint limits concurrent access.

• Memory search capabilities are limited compared to server databases.

Best suited for analytics pipelines and offline agent evaluation.

ADBC

ADBC (Arrow Database Connectivity) provides a driver-agnostic interface:

• Works with any ADBC-compatible driver (PostgreSQL, SQLite, DuckDB, etc.).

• Arrow-native data transfer for high-throughput event ingestion.

• Backend capabilities depend on the underlying database driver.

Spanner

Google Cloud Spanner provides globally distributed ADK storage:

• Cloud-managed, horizontally scalable.

• Full-text search support for memory entries.

• Strong consistency across regions.

• Suitable for multi-region agent deployments.

Configuration

All backends are configured through extension_config["adk"]:

from sqlspec.adapters.asyncpg import AsyncpgConfig

config = AsyncpgConfig(
    connection_config={"dsn": "postgresql://localhost/mydb"},
    extension_config={
        "adk": {
            "session_table": "adk_sessions",
            "events_table": "adk_events",
            "memory_table": "adk_memory_entries",
            "memory_use_fts": True,
            "artifact_table": "adk_artifact_versions",
            "owner_id_column": "tenant_id INTEGER NOT NULL",
        }
    },
)

See Adapters for adapter-specific configuration patterns.