LanceDB | Respan Docs

LanceDB is a serverless vector database built on the Lance columnar format. It supports embedded (in-process) and cloud deployments, with automatic versioning, fast retrieval, and native integration with ML frameworks. Respan gives you full observability over every table operation, vector search, and filter query.

Set up Respan

Create an account at platform.respan.ai and grab an API key.

Run npx @respan/cli setup to set up with your coding agent.

Example projects

Python examples

Tracing

Setup

Install packages

$ pip install respan-ai opentelemetry-instrumentation-lancedb lancedb

Set environment variables

$ export RESPAN_API_KEY="YOUR_RESPAN_API_KEY"

RESPAN_API_KEY is used to export traces to Respan.

Initialize and run

1 import lancedb
2 from respan import Respan
3 from opentelemetry.instrumentation.lancedb import LanceInstrumentor
4 
5 respan = Respan(instrumentations=[LanceInstrumentor()])
6 
7 db = lancedb.connect("/tmp/lancedb")
8 
9 data = [
10     {"text": "Respan provides AI observability.", "vector": [0.1, 0.2, 0.3, 0.4]},
11     {"text": "Vector databases enable semantic search.", "vector": [0.5, 0.6, 0.7, 0.8]},
12     {"text": "LanceDB uses the Lance format.", "vector": [0.2, 0.3, 0.4, 0.5]},
13 ]
14 table = db.create_table("documents", data, mode="overwrite")
15 
16 results = table.search([0.1, 0.2, 0.3, 0.4]).limit(2).to_list()
17 for result in results:
18     print(result["text"], result["_distance"])
19 
20 respan.flush()

View your trace

Open the Traces page to see your LanceDB operation spans with table operations, vector searches, and filters.

Configuration

Parameter	Type	Default	Description
`api_key`	`str \| None`	`None`	Falls back to `RESPAN_API_KEY` env var.
`base_url`	`str \| None`	`None`	Falls back to `RESPAN_BASE_URL` env var.
`instrumentations`	`list`	`[]`	Plugin instrumentations to activate (e.g. `LanceInstrumentor()`).
`customer_identifier`	`str \| None`	`None`	Default customer identifier for all spans.
`metadata`	`dict \| None`	`None`	Default metadata attached to all spans.
`environment`	`str \| None`	`None`	Environment tag (e.g. `"production"`).

Attributes

In Respan()

1 from respan import Respan
2 from opentelemetry.instrumentation.lancedb import LanceInstrumentor
3 
4 respan = Respan(
5     instrumentations=[LanceInstrumentor()],
6     customer_identifier="user_123",
7     metadata={"service": "rag-api", "version": "1.0.0"},
8 )

With propagate_attributes

1 from respan import Respan, propagate_attributes
2 from opentelemetry.instrumentation.lancedb import LanceInstrumentor
3 
4 respan = Respan(instrumentations=[LanceInstrumentor()])
5 
6 def search(user_id: str, query_vector):
7     with propagate_attributes(
8         customer_identifier=user_id,
9         thread_identifier="conv_abc_123",
10         metadata={"plan": "pro"},
11     ):
12         return table.search(query_vector).limit(2).to_list()

Attribute	Type	Description
`customer_identifier`	`str`	Identifies the end user in Respan analytics.
`thread_identifier`	`str`	Groups related messages into a conversation.
`metadata`	`dict`	Custom key-value pairs. Merged with default metadata.