Stacked on #4173 (`jack/restore-oidc-flows`, base branch mirrored to this repo so the diff shows only this change); context from review: https://github.com/lancedb/lancedb/pull/4173#issuecomment-5674048100. Rebase to `main` once #4173 and #4179 merge. ## What moved to the `oauth2` crate (5.0, no default features) - Authorization URL generation and CSRF state (`authorize_url`, `CsrfToken`) - PKCE S256 challenge/verifier generation and code exchange - Client-credentials, authorization-code, refresh-token, and device-code grant request construction - Device authorization request and the device token polling loop (`authorization_pending`, `slow_down` +5s, expiry deadline, denial, network backoff capped at 10s) - Standard success/error response parsing (`RequestTokenError`) - Token-endpoint client authentication and standards-compliant parameter encoding (RFC 6749 2.3.1 Basic encoding) LanceDB keeps ownership of OIDC discovery (compared `openidconnect`: no measurable win for our 3-field metadata + strict validation, at real dependency cost), HTTPS-or-loopback endpoint enforcement, the loopback callback server, browser/stderr prompts, token caching and refresh orchestration, and the dedicated hardened Azure IMDS source, which is unchanged. ## Client authentication methods New `ClientAuthMethod` enum (`none` | `client_secret_basic` | `client_secret_post`), exposed in Rust, Python, and Node. Unset resolves to `client_secret_basic` when a secret is present (RFC 6749 2.3.1 recommendation and the normal Okta confidential-app default, so a default Okta app works without weakening its configuration) and to `none` for public clients (PKCE/device). Explicit `none` with a secret, or basic/post without one, is rejected. The method applies to client credentials, code exchange, refresh, and device requests. Deliberate behavior change: confidential clients previously always sent the secret in the POST body; they now default to Basic (Keycloak accepts both). No `audience`/`resource` parameters were added: the supported target is an Okta custom authorization server with the API audience configured server-side, so client-provided audience parameters are unnecessary; `add_extra_param` support exists if a concrete provider contract ever needs them. ## Device polling behavior changes (deliberate, tested) - The first token poll now happens immediately rather than after one interval (RFC 8628 allows both). - Transient failures (HTTP 429, 5xx, `temporarily_unavailable`, network errors) now retry with exponential backoff capped at 10s instead of retrying at the fixed interval; polling never spins faster than once per second even if a server reports a zero interval. ## Security and compatibility - Issuer and discovered endpoints (and device verification URIs) still require HTTPS except explicit loopback HTTP, enforced before any crate URL type is built - Token HTTP client keeps the hardened redirect policy that refuses insecure redirect targets; regression test added - Errors never embed raw response bodies (avoids leaking tokens through parse failures); all credential types stay redacted in Debug - Transient conditions (429/5xx/`temporarily_unavailable`) remain retryable in device polling and hard errors elsewhere; refresh keeps rotation and reauthentication semantics - Existing public APIs stay source-compatible except the added `OAuthConfig.client_auth_method` field ## Tests Rust: client-auth methods across code exchange/refresh/client-credentials/device (none/basic/post), auth-method resolution and validation, transient device retries, denial/expiry, redirect rejection, malformed-response leak check, PKCE URL assertions, redaction. Python and Node: enum values, conversion, unknown-method errors, config defaults. Manual Okta validation recipe (no automated Okta credentials): create a custom authorization server with an API audience, one confidential web app (Basic) for authorization-code, one native app (PKCE, no secret), one native device app; point `issuer_url` at the custom server, set `client_auth_method` only for the POST-required case; verify token acquisition, refresh after expiry, and `x-lancedb-credential-type: oidc` against a LanceDB deployment. Never commit tenant URLs or secrets. Co-authored-by: Xuanwo <github@xuanwo.io>
LanceDB Python SDK
A Python library for LanceDB.
Installation
pip install lancedb
Pre-Haswell x86_64 hosts: lancedb-compat
The default lancedb wheel targets x86-64-haswell (AVX2 + FMA + F16C) for full performance on modern hardware. Pre-Haswell hosts — Intel Sandy Bridge / Ivy Bridge / Westmere; AMD Bulldozer / Piledriver / Steamroller — don't have AVX2 and crash with Illegal instruction at import lancedb.
For those hosts, install the lancedb-compat package instead:
pip install lancedb-compat
Same Python API (import lancedb works as usual). The compat wheel is compiled at the x86-64-v2 baseline (Nehalem-class) and uses runtime SIMD dispatch in the embedded lance crate to pick the right kernel tier (scalar / AVX / AVX+FMA / AVX2+FMA / AVX-512) at load time, so it still goes fast on modern hardware while running cleanly on the pre-Haswell silicon. Use lance.simd_info() from Python to verify which tier was selected.
lancedb and lancedb-compat install to the same lancedb/ namespace and conflict at install time. Pick one. To switch, pip uninstall lancedb first, then pip install lancedb-compat (or vice-versa).
If you need a custom baseline (or lancedb-compat isn't yet published for your platform), build from source with the override:
RUSTFLAGS="-C target-cpu=x86-64-v2" maturin build --release
pip install ./target/wheels/lancedb-*.whl
Preview Releases
Stable releases are created about every 2 weeks. For the latest features and bug fixes, you can install the preview release. These releases receive the same level of testing as stable releases, but are not guaranteed to be available for more than 6 months after they are released. Once your application is stable, we recommend switching to stable releases.
pip install --pre --extra-index-url https://pypi.fury.io/lancedb/ lancedb
Threading in CPU-limited containers
LanceDB uses separate pools for compute work and storage I/O. On a container with two visible CPUs, current releases intentionally use one compute worker by default; no manual configuration is needed. If every query logs an I/O core reservation warning on a two-CPU container, upgrade from LanceDB 0.21.1 or earlier.
The two commonly tuned environment variables control different resources:
LANCE_CPU_THREADSoverrides the number of compute workers. One worker is the appropriate setting for a two-CPU container when an explicit override is needed.LANCE_IO_THREADScontrols concurrent storage operations, not reserved CPU cores. Its default can be greater than the number of CPUs because I/O workers spend much of their time waiting for storage.
Keep the defaults unless measurements show that the workload benefits from an override. See the Lance threading model for the current defaults and tuning guidance.
Usage
Basic Example
import lancedb
db = lancedb.connect('<PATH_TO_LANCEDB_DATASET>')
table = db.open_table('my_table')
results = table.search([0.1, 0.3]).limit(20).to_list()
print(results)
Development
See CONTRIBUTING.md for information on how to contribute to LanceDB.