[Feature]: Support "Less Than" Operators in Query

[CalebCourier]

Description

A common need when querying traces is to filter by a time range. While WeaveClient.get_calls supports greater than ($gt) and greater than or equal to ($gte) operators in Query expressions, it does not support any of the less than operators making it impossible to query by a time range.

To illustrate this, the following code sample yields the subsequent error:

query = {
    "$expr": {
        "$and": [
            { "$gte": [{ "$getField": "started_at" }, { "$literal": start_time }] },
            { "$lt": [{ "$getField": "ended_at" }, { "$literal": end_time }] }
        ]
    }
}


weave_client = weave.init(f"{entity}/{project}")
traces = weave_client.get_calls(
    query=query
)

pydantic_core._pydantic_core.ValidationError: 18 validation errors for WeaveClient.get_calls
query.$expr.AndOperation.$and.1.LiteralOperation.$literal
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.GetFieldOperator.$getField
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.ConvertOperation.$convert
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.AndOperation.$and
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.OrOperation.$or
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.NotOperation.$not
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.EqOperation.$eq
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.GtOperation.$gt
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.GteOperation.$gte
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.InOperation.$in
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.AndOperation.$and.1.ContainsOperation.$contains
  Field required [type=missing, input_value={'$lt': [{'$getField': 'e...iteral': 1761919200.0}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.OrOperation.$or
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.NotOperation.$not
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.EqOperation.$eq
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.GtOperation.$gt
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.GteOperation.$gte
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.InOperation.$in
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing
query.$expr.ContainsOperation.$contains
  Field required [type=missing, input_value={'$and': [{'$gte': [{'$ge...eral': 1761919200.0}]}]}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.11/v/missing

Suggested Solution

The Query pydantic model, and any downstream services, should support $lt and $lte operators.

Weave Project Link

https://wandb.ai/ml-guardrails/gen-traces-without-run/weave

Screenshots or Mockups

No response

[jwlee64]

Hi @CalebCourier,
I will add a ticket to add $lt and $lte to our query service.
In the meantime, a solid workaround is to use $not and then the $gt
Something like below

query = {
    "$expr": {
        "$and": [
            { "$gte": [{ "$getField": "started_at" }, { "$literal": start_time }] },
            { "$not": [{ "$gt": [{ "$getField": "ended_at" }, { "$literal": end_time }] }]}
        ]
    }
}


weave_client = weave.init(f"{entity}/{project}")
traces = weave_client.get_calls(
    query=query
)