aura-connector 0.6.0

Async, typed Python data connector for AuraDB and existing databases.

Aura Connector

A typed async Python connector and query layer for AuraDB.

Aura Connector is an async, typed Python client for AuraDB and a uniform query layer over the databases you already run. Declare typed models once, compose injection-safe queries with a fluent builder, and run them against AuraDB or another backend by changing only the DSN. AuraDB is the native, high-performance target over the Aura Wire Protocol; the other backends make the same model and query API useful immediately on existing infrastructure.

Aura Connector v0.6.0 is the matching client for AuraDB v1.2.0 (query ergonomics: aggregations, terms facets, cooperative query timeouts), building on the v1.1.0 search and ranking features (search_text BM25, search_vector, search_hybrid). The .timeout(ms) query option is now enforced end-to-end by AuraDB v1.2.0. Feature differences between backends are honest: search/ranking APIs require AuraDB capabilities, and a backend that does not support a requested feature raises a structured capability error instead of pretending to support it.

It is useful today with zero setup — the package ships an in-memory reference backend and first-class SQLite, so the examples and the full default test suite run with no external database and no compiler.

import asyncio
from aura import Aura, Model, Field, Vector


class Document(Model):
    id: int = Field(primary_key=True)
    title: str
    body: str
    embedding: Vector[3]


async def main() -> None:
    async with Aura.connect("aura+memory://localhost/app", models=[Document]) as client:
        await client.insert(Document(id=1, title="Refunds", body="...", embedding=[1, 0, 0]))

        # Typed, injection-safe query building.
        docs = await (
            client.query(Document)
            .where(Document.title.contains("Refund"))
            .order_by(Document.id.desc())
            .limit(10)
            .all()
        )

        # Exact vector nearest-neighbour search.
        matches = await (
            client.search(Document)
            .nearest(Document.embedding, [1, 0, 0], metric="cosine")
            .limit(5)
            .all()
        )
        print(docs, matches)


asyncio.run(main())

Why it matters

Python data access usually forces a trade: ORMs give typed models but hide the wire and leak lazy queries; raw drivers give control but hand back untyped tuples and string SQL; vector search lives in yet another SDK. Aura Connector unifies these behind one typed async client.

• One typed client for relational, document, vector, hybrid, and graph access.
• Async-first. asyncio is the primary execution model, not a wrapper.
• Explicit relationship loading. No hidden lazy network IO — .include() is required, and accessing an unloaded relationship raises a clear error.
• Injection-safe by construction. Queries compile to an immutable AST and Query IR, never to concatenated strings.
• Honest about backends. Unsupported features raise a structured error rather than being silently emulated.

Install

The base install is dependency-free and includes the AuraDB protocol and in-memory backends. Add an extra for each database backend you want:

pip install aura-connector                 # core: AuraDB protocol + in-memory backend
pip install "aura-connector[sqlite]"       # SQLite        (aiosqlite)
pip install "aura-connector[postgres]"     # PostgreSQL    (asyncpg)
pip install "aura-connector[mysql]"        # MySQL/MariaDB (aiomysql)
pip install "aura-connector[mongodb]"      # MongoDB       (motor)
pip install "aura-connector[redis]"        # Redis         (redis.asyncio)
pip install "aura-connector[sql]"          # SQLite + PostgreSQL + MySQL
pip install "aura-connector[all-db]"       # every database driver
pip install "aura-connector[native]"       # + optional native acceleration tooling

Selecting a backend whose driver is not installed raises AuraDriverNotInstalledError with the exact install command. Requires Python 3.11+; the pure-Python path needs no compiler. The import package is aura. Optional native acceleration (CRC32 and f32 vector packing) is built with maturin from crates/aura_native — see Native acceleration.

Compatibility

The connector reads the connected backend's advertised capabilities at handshake, so it adapts to the server version rather than assuming one.

Aura Connector	AuraDB server	Protocol	Status
0.5.x	1.1.x	AWP 1	Recommended — first-class search and ranking (search_text BM25, search_vector, search_hybrid), typed scores, capability negotiation.
0.5.x	1.0.x	AWP 1	Basic operations supported. Search APIs raise AuraCapabilityError because a pre-1.1.0 server does not advertise BM25/hybrid.
0.4.x	0.7.x / 1.0.x / 1.1.x	AWP 1	Older line — CRUD, transactions, exact vector, and cluster-preview ergonomics; predates the search APIs.
0.3.x	0.2.x+	AWP 1	Native AuraDB backend (auth + TLS); no typed not_leader ergonomics.
0.2.x	—	n/a	Not compatible with the authenticated, TLS-capable native backend.

The search clauses are additive Query IR, so AWP 1 is unchanged across these rows. See docs/COMPATIBILITY.md.

Quick start

The fastest start needs no external service — SQLite (local) or the in-memory engine. Switch to AuraDB or another database by changing only the DSN.

import asyncio
from aura import Aura, Model, Field

class User(Model):
    id: int = Field(primary_key=True)
    email: str = Field(unique=True, index=True)
    display_name: str | None = Field(default=None)

async def main() -> None:
    async with Aura.connect("sqlite:///app.db", models=[User]) as db:
        await db.insert(User(id=1, email="[e-mail]", display_name="Ada"))
        ada = await db.User.find(id=1)
        print(ada.display_name)

asyncio.run(main())

The same code runs against other backends by changing only the DSN:

async with Aura.connect("postgresql://user:pass@localhost:5432/app", models=[User]) as db: ...
async with Aura.connect("mongodb://localhost:27017/app", models=[User]) as db: ...
async with Aura.connect("auras://db.example.com:7171/app", models=[User]) as db: ...   # AuraDB over TLS

See Getting started, Models, and the Query builder.

AuraDB native backend

The auradb:// (plaintext) and auradbs:// (TLS) schemes connect to a running AuraDB server over Aura Wire Protocol 1, including static-token authentication, TLS, and transactions with read-your-writes. AuraDB v1.2.0 is the current coordinated server; the native backend speaks AWP 1, which is frozen for the AuraDB v1 line.

from aura import connect
from aura.config import TokenAuth, TLSConfig

async with connect(
    "auradbs://db.example.com:7171/app",
    models=[User],
    auth=TokenAuth("my-secret-token"),
    tls=TLSConfig(enabled=True, ca_cert_path="/etc/aura/ca.pem"),
) as client:
    async with client.transaction() as tx:
        await tx.insert(User(id=1, email="[e-mail]"))
        # Read-your-writes: visible inside the transaction, not outside until commit.
        assert await tx.query(User).where(User.id == 1).count() == 1

A certificate the CA does not validate, or a hostname mismatch, fails the handshake — the client never silently downgrades to plaintext. The legacy aura:// / memory:// schemes use the connector's bundled reference protocol path, not the AuraDB network server. See docs/AURADB.md.

Search and ranking

Against AuraDB v1.1.x and later (and the in-memory reference backend), the connector exposes first-class ranked search. Exact vector search is the default and correctness baseline; against AuraDB v1.2.0 the connector can opt a vector query into the approximate (HNSW) preview (search_vector(..., approximate=True)) — not production ANN.

from aura import search_scores

# Ranked full-text (BM25).
rows = await client.search(Doc).search_text("body", "vector index", rank="bm25").all()

# Exact vector search.
rows = await client.search(Doc).search_vector("embedding", q, metric="cosine", top_k=10).all()

# Hybrid text + vector, fused.
rows = await (
    client.search(Doc)
    .search_hybrid("body", "vector index", "embedding", q,
                   weights=(0.5, 0.5), fusion="weighted_sum", top_k=10)
    .all()
)

for row in rows:
    s = search_scores(row)
    print(s.rank, s.score, s.text_score, s.vector_score)

.explain() on any query or search builder returns the client-side Query IR plan; the server-measured plan is available through AuraDB's auradb search explain --analyze. Search/ranking APIs require AuraDB capabilities. The connector checks the connected backend's advertised capabilities first; a backend that does not support a requested feature raises AuraCapabilityError rather than emulating it. client.capabilities() is the authoritative source for what the connected server supports. See docs/SEARCH_AND_RANKING.md and the auradb_text_search, auradb_hybrid_search, auradb_explain_analyze, and auradb_search_capabilities examples.

Backends

The DSN scheme selects the backend — nothing else in your code changes:

Scheme(s)	Backend	Extra
auradb://, auradbs://	AuraDB server (native AWP 1 over TCP/TLS) — auth + TLS	—
aura://, auras://, aura+tcp://	AuraDB reference protocol path (bundled; not the network server)	—
aura+memory://, memory://	In-memory reference engine	—
sqlite://, sqlite+aiosqlite://	SQLite (first-class local)	[sqlite]
postgres://, postgresql://, postgresql+asyncpg://	PostgreSQL	[postgres]
mysql://, mariadb://, …+aiomysql://	MySQL / MariaDB	[mysql]
mongodb://, mongodb+motor://	MongoDB (document-native)	[mongodb]
redis://, redis+asyncio://	Redis (limited key-value / cache)	[redis]

Capability	AuraDB	Memory	SQLite	PostgreSQL	MySQL	MongoDB	Redis
CRUD + filters	yes	yes	yes	yes	yes	yes	by key
Transactions	yes	yes	yes	yes	yes	no¹	no
Relationships	yes	yes	yes	yes	yes	yes	no
JSON / document fields	yes	yes	yes²	yes²	yes²	yes	yes
Full-text search	yes	yes	no	yes	yes	no	no
Vector / hybrid search	yes	yes	no	no	no	no³	no
Graph traversal	yes	yes	no	no	no	no	no

¹ MongoDB transactions require a replica set. ² SQL backends store JSON/vector fields as JSON text (the documented fallback). ³ MongoDB vector search requires a configured vector index. Unsupported features raise AuraCapabilityError (alias AuraBackendCapabilityError) — never silently emulated. Per-backend guides: AuraDB · SQLite · PostgreSQL · MySQL · MongoDB · Redis. See docs/BACKENDS.md and the capability matrix.

Error handling

Errors carry stable codes and non-sensitive context and never embed credentials. Two are central to AuraDB use:

• AuraCapabilityError — a requested feature (e.g. BM25 or hybrid search) is not supported by the connected backend. The message names the backend and the missing capability so callers can branch on it.
• AuraNotLeaderError — in AuraDB's multi-node preview, a write reached a follower. It carries the leader-routing hints (leader_addr, leader_node_id, current_node_id, retryable, …). A retryable=True does not mean the connector retries automatically.

See the full taxonomy in docs/ERRORS.md.

Transactions

The native backend supports begin / commit / rollback with read-your-writes; reads inside a transaction observe its own staged writes and not its staged deletes, invisible to other connections until commit. The model is snapshot isolation: read-your-writes over committed state with optimistic (first-committer-wins) conflict detection on commit. It is not serializable isolation, and the connector does not upgrade it. transaction(isolation=…) defaults to "snapshot"; "serializable" is accepted only as a deprecated compatibility alias for snapshot isolation.

In the cluster preview, transaction ids are node-local and a redirect mid-transaction is not performed automatically: if a leader changes, restart the transaction against the new leader. AuraDB's multi-node mode has no production high availability or automatic failover — single-node is the recommended production deployment. See docs/TRANSACTIONS.md and the auradb_not_leader / auradb_leader_redirect examples.

AuraDB boundary

This package is the client and connector. AuraDB server features (storage, server-side cost-based planning, distributed transaction coordination on a live cluster) live in the separate AuraDB project. Operations that require a live server fail with a structured error rather than pretending to succeed. See AuraDB boundary.

Documentation

• Getting Started · Architecture · AuraDB boundary
• Models · Query Builder · Client · Vectors
• Search & Ranking · Transactions · Errors · Migrations
• AuraDB backend · Backends · Capability matrix
• Protocol · Transports · SQL compiler · Native acceleration
• Observability · CLI · Compatibility · Testing · Roadmap

Testing

python -m pytest -vv

The suite is deterministic and requires no external services. It covers models, fields, vectors, schema generation, the query builder, protocol frames and golden bytes, transports, client lifecycle, hydration, errors, migrations, observability, typing, and example smoke tests. See Testing.

Security

The client validates and length-bounds every protocol frame, fails closed on protocol errors, never embeds secrets in errors or logs, and redacts credentials in configuration repr. To report a vulnerability, see SECURITY.md.

Contributing

Contributions are welcome. See CONTRIBUTING.md for setup, the dev and native build, test commands, and code style, and the Code of Conduct.

License

Apache-2.0. See LICENSE.