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Improvements to Chalk are published here! See our public roadmap for upcoming changes.

Jan 22, 2024

required_resolver_tags for queries

You can now specify required_resolver_tags when querying. This allows you to ensure that a query only considers a resolver if it has a certain tag. This is useful for guaranteeing that a query only uses resolvers that are cost-efficient, or for enforcing certain compliance workflows.

In this example:

def fetch_credit_scores() -> DataFrame[, User.credit_score]:
    Call bureaus to get credit scores; costs money for each record retrieved.


def fetch_previously_ingested_credit_scores() -> DataFrame[, User.credit_score]:
    Pull previously retrieved credit scores from Snowflake only

    return snowflake.query_string("select user_id as id, credit_score from ...").all()

querying with required_resolver_tags can be used to enforce that only ‘low-cost’ resolvers are executed —

# This query is guaranteed to /never/ run any resolver that isn't tagged "low-cost".

dataset = ChalkClient().offline_query(

October 24th, 2023

Support for Python 3.11

You can now use either of Python 3.11 or 3.10 on a per-environment basis.

project: my-project-id
    runtime: 3.10
    runtime: 3.11

See Python Version for more information.

October 23rd, 2023

Quality of Life Improvements

  • ChalkClient.query_bulk(...) and multi_query no longer require that references features be defined as Python classes, and string names for inputs and outputs can now be used instead.

October 11th, 2023

Alert descriptions

Alerts now support descriptions, which can be used to provide more context about the alert.

from chalk.monitoring import Chart, Series
Chart(name="Request count").with_trigger(
      .where(feature=User.fico_score) > 0.2,

  When this alert is triggered, we're parsing null values from
  a lot of our FICO reports. It's likely that Experian is
  having an outage. Check the <dashboard|>.

These descriptions can also be set in the Chalk dashboard via the metric alerts interface.

Alert description interface:

October 5th, 2023

query_bulk support for notebooks

The query_bulk method is now available in the ChalkClient class. This method allows you to query for multiple rows of features at once.

This method uses Apache Arrow’s Feather format to encode data. This allows the endpoint to transmit data (particularly numeric-heavy data) using roughly 1/10th the bandwidth that is required for the JSON format used by query.

This method has been available in beta for a few months, but is now available for general use, and as part of this release is now supported when querying using notebooks without access to feature schemas.

September 26, 2023

Improve scheduled resolver runs list

The list of scheduled resolvers now shows which resolvers are actually scheduled to run in the current environment, based on the environment argument to @online and @offline.

Scheduled Resolvers List:

Resolvers that are annotated with an environment other than the current environment are labeled with the environment in which they are configured to run.

August 23, 2023

Improved chalk query output

The chalk query command now has improved output for errors. Previously, errors were displayed in a table, which meant that stacktraces were truncated:

> chalk query --in --out email


Code             Feature  Resolver                        Message
RESOLVER_FAILED           src.resolvers.get_fraud_tags    KeyError: 'tags'

Now, errors are displayed in a more readable format, and stacktraces are not truncated:

> chalk query --in --out email


Resolver Failed src.resolvers.get_fraud_tags

KeyError: 'tags'
  File "src/", line 30, in get_fraud_tags
      return parsed["tags"]


August 19, 2023

Query plan trace viewer

The query plan viewer now includes a flame graph visualization of the query plan’s execution, called the Trace View. Precise trace data is stored for every offline query by default and for online queries when the query is made with the --explain flag.

Trace View:

August 11, 2023

Override now in online query

  • Support now= for .query, --now, etc.

Query plan viewer improvements

  • Redesigned query plan viewer
  • Support viewing execution time per operator
  • Support viewing data processing metrics per operator
  • Query plans saved for all queries by default

No-input online and offline query improvements

  • offline_query now supports running downstream resolvers when no input is provided. Query primary keys will be sampled or computed, depending on the value of recompute_features.
  • online_query now support running a query without any input. Query primary keys will be computed using an appropriate no-argument resolver that returns a DataFrame[...]


  • --local for chalk query, combines chalk apply --branch and chalk query --branch
  • The progress indicator in the chalk command line tool is no longer an off-brand magenta.

August 5, 2023

Chalk Python SDK Improvements

Added: .to_polars(), to_pandas(), and .to_pyarrow() accept prefixed: bool as an argument. prefixed=True is the default behavior, and will prefix all column names with the feature namespace. prefixed=False will not prefix column names.

DataFrame({ ["Andy"]}).to_polars(prefixed=False)
# output:
# polars DataFrame with `name` as the sole column.

DataFrame({ ["Andy"]}).to_polars(prefixed=True)
# output:
# polars DataFrame with `` as the sole column.

Added: include_meta on ChalkClient.query(...), which includes .meta on the response object. This metadata object includes useful information about the query execution, at the cost of increased network payload size and a small increase in latency.

July 25, 2023

Freezing time in unit tests

Chalk now supports freezing time in unit tests. This is useful for testing time-dependent resolvers.

from datetime import timezone, datetime
from chalk.features import DataFrame, after
from chalk.features.filter import freeze_time

df = DataFrame([...])
with freeze_time(at=datetime(2020, 2, 3, tzinfo=timezone.utc)):
    df[after(days_ago=1)] # Get items after february 2nd

freeze_time also works with resolvers that declare specific time bounds for their aggregation inputs:

def get_num_transactions(txs: Card.transactions[before(days_ago=1)]) -> Card.num_txs:
  return len(txs)

with freeze_time(at=datetime(2020, 9, 14)):
    num_txs = get_num_transactions(txs) # num transactions before september 13th

July 11, 2023

Explicitly time-dependent resolvers

Chalk now supports resolvers that are explicitly time-dependent. This is useful for performing backfills which compute values that depend on values that are semantically similar to

You can express time-dependency by declaring a dependency on a special feature called Now:

def get_age_in_years(birthday: User.birthday, now: Now) -> User.age_in_years:
    return (now - birthday).years

In online query, (i.e. with ChalkClient().query), Now is In offline query contexts, now will be set to the appropriate input_time value for the calculation. This allows you to backfill a feature for a single entity at many different historical time points:

ChalkClient().offline_query(input={ [1,1,1]}, output=[User.age_in_years], input_times=[ - timedelta(days_ago=100), - timedelta(days_ago=50), - timedelta(days_ago=0),

Now can be used in batch resolvers as well:

def batch_get_age_in_years(df: DataFrame[, User.birthday, Now]) -> DataFrame[, User.age_in_years]:

June 21, 2023

Testing your SQL File Resolvers

SQL file resolvers are Chalk’s preferred method of resolving features with SQL queries. Now, you can get your SQL file resolvers in Python by the name of the SQL file resolver. For example, if you have the following SQL file resolver:

-- source: postgres
-- cron: 1h
-- resolves: Person
select id, name, email, building_id from table where id=${}

you can test out your resolver with the following code.

from chalk import get_resolver

resolver = get_resolver('example') # get_resolver('example.chalk.sql') will also work
result = resolver('my_id')

June 15, 2023

Metrics Export Updates

Now, Chalk supports exporting metrics about “named query” execution. These metrics (count, latency) join similar metrics about feature and resolver execution. Contact your Chalk Support representative to configure metrics export if you would like to view metrics about Chalk system execution in your existing metrics dashboards.

Additional updates:

  • synthetic cache resolvers are now excluded
  • query_name is a tag on many metrics

June 14, 2023

Branch deployment performance

Chalk Branch Deployments provide an excellent experience for quick iteration cycles on new features and resolvers. Now, Chalk Branch Deployments automatically use a pool of “standby” workers, so there is less delay before queries can be served against a new deployment. This reduces the time it takes to run query or offline query against a new deployment from ~10-15 seconds to ~1-3 seconds. This impacts customers with more complex feature graphs the most.

June 13, 2023

Expanded support for logical keying in streaming contexts

Stream resolvers support a keys= parameter. This parameter allows you to re-key a stream by a property of the message, rather than relaying on the protocol layer key. This is appropriate if a stream is keyed randomly, or by an entity key like “user”, but you want to aggregate along a different axis, e.g. “organization”.

Now, keys= supports passing a “dotted string” (e.g. to indicate that Chalk should use a sub-field of your message model. Previously, only root-level fields of the model were supported.

DataFrame unit tests

If you specify projections or filters in DataFrame arguments of resolvers, Chalk will automatically project out columns and filter rows in the input data.

Below, we test a resolver that filters rooms in a house to only the bedrooms:
class Room:
    id: str
    name: str

class Home:
    id: str
    rooms: DataFrame[Room] = has_many(
        lambda: Room.home_id ==
    num_bedrooms: int

def get_num_bedrooms(
    rooms: Home.rooms[ == 'bedroom']
) -> Home.num_bedrooms:
    return len(rooms)

Now, we may want to write a unit test for this resolver.
def test_get_num_rooms():
    # Rooms is automatically converted to a `DataFrame`
    rooms = [
        Room(id=1, name="bedroom"),
        Room(id=2, name="kitchen"),
        Room(id=3, name="bedroom"),

    # The kitchen room is filtered out
    assert get_num_bedrooms(rooms) == 2

    # `get_num_bedrooms` also works with a `DataFrame`
    assert get_num_bedrooms(DataFrame(rooms)) == 2

While we could have written this test before, we would have had to manually filter the input data to only include bedrooms. Also note that Chalk will automatically convert our argument to a DataFrame if it is not already one.

June 12, 2023

Query Run Page

Chalk’s dashboard shows aggregated logs and metrics about the execution of queries and resolvers. Now, it can also show detailed metrics for a single query. This is useful for debugging and performance tuning.

You can access this page from the “runs” tab on an individual named query page, or from the “all query runs” link on the “queries” page.

You can search the list of previously executed queries by date range, or by “query id”. The query id is returned in the “online query” API response object.

May 15, 2023

BigTable Online Storage

Chalk now supports BigTable as an online-storage implementation. BigTable is appropriate for customers with large working sets of online features, as is common with recommendation systems. We have successfully configured BigTable to serve 700,000 feature vectors per second at ~30ms p90 e2e latency.

May 10, 2023

Enhancements to Offline Query

The Offline Query has been enhanced with a new recompute_features parameter. Users can control which features are sampled from the offline store, and which features are recomputed.

  • The default value False will maintain current behavior, returning only samples from the offline store.
  • True will ignore the offline store, and execute @online and @offline resolvers to produce the requested output.
  • If, instead, the user passes in a list of features to recompute_features, those features will be recomputed by running @online and @offline resolvers, and all other feature values - including those needed to recompute the requested features - will be sampled from the offline store.

Recompute Dataset

The ‘recompute’ capability is also exposed on Dataset. When passed a list of features to recompute, a new Dataset Revision will be generated, and the existing dataset will be used as inputs to recompute the requested features.

Developing in Jupyter

Chalk has introduced a new workflow when working with branches, allowing full iterations to take place directly in any IPython notebook. When a user creates a Chalk Client with a branch in a notebook, subsequent features and resolvers in the notebook will be deployed to that branch. When combined with Recompute Dataset and the enhancements to Offline Query, users have a new development loop available for feature exploration and development:

  1. Take advantage af existing data in chalk
  2. Explore that data using familiar tools in a notebook
  3. Enrich the data by developing new features and resolvers
  4. Immediately view the results of adjusting features in the dataset
  5. When exploration is complete, features and resolvers can be directly added back to the Chalk project

May 5, 2023

View Deployment Source Code

Deployments now offer the ability to view their source code. By clicking the “View Source” button on the Deployment Detail page, users can view all files included in the deployed code.

April 21, 2023

Improved Deployment Utilities

Users can now “redeploy” any historical deployement with a UI button on the deployment details page. This enables useful workflows including rollbacks. The “download source” button downloads a tarball containing the deployed source to your local machine. Deploy UI Enhancements

April 18, 2023

Resolver error messages for incorrect types include primary keys

When writing resolvers, incorrect typing can be a difficult to track. Now, if a resolver instantiates a feature of an incorrect type, the resolver error message will include the primary key value(s) of the query itself.

April 11, 2023

Online query improvements

The Online Query API can now be used to query DataFrame-typed features. For instance, you can query all of a user’s transaction level features in a single query:

chalk query --in --out user.transactions

  "columns": ["", "transaction.user_id", ...],
  "values": [[1, 2, 3, ...], ["user_1", "user_2", "user_3", ...]

More functionality will be added to Online and Offline query APIs to support more advanced query patterns.

April 6, 2023

Branch deployments

When deploying with chalk apply a new flag --branch <branch_name> has been introduced which creates a branch deployment. Users can interact with their branch deployment using a consistent name by passing the branch name to query, upload_features, etc. Chalk clients can also be scoped to a branch by passing the branch in the constructor. Branch deployments are many times faster than other flavors of chalk apply, frequently taking only a few seconds from beginning to end. Branch deployments replace preview deploys, which have been deprecated.

March 31, 2023

Speed improvements for deployments

Deployments via chalk apply are now up to 50% faster in certain cases. If your project’s PIP dependencies haven’t changed, new deployments will build & become active significantly faster than before.

Deploy Time Comparison:

March 17, 2023

Offline TTL

Introduces a new “offline_ttl” property to features decorator . Now you can control for how long data is valid in the offline_store. Any feature older than the ttl value will not be returned in an offline query.

class MaxOfflineTTLFeatures:
    id: int
    ts: datetime = feature_time()

    no_offline_ttl_feature: int = feature(offline_ttl=timedelta(0))
    one_day_offline_ttl_feature: int = feature(offline_ttl=timedelta(days=1))
    infinite_ttl_feature: int

Strict Feature Validation

Adds the strict property to features decorator, indicating that any failed validation will throw an error. Invalid features will never be written to the online or offline store is strict is True. Also introduces the validations array to allow differentiated strict and soft validations on the same feature.

class ClassWithValidations:
    id: int
    name: int = feature(max=100, min=0, strict=True)
    feature_with_two_validations: int = feature(
            Validation(min=70, max=100),
            Validation(min=0, max=100, strict=True),

March 7, 2023

Datasets in Offline Query

The Dataset class is now live! Using the new ChalkClient.offline_query method, we can inspect important metadata about the query and retrieve its output data in a variety of ways.

Simply attach a dataset_name to the query to persist the results.

from chalk.client import ChalkClient, Dataset
uids = [1, 2, 3, 4]
at =
dataset: Dataset = ChalkClient().offline_query(
     input={ uids,
         User.ts: [at] * len(uids),
pandas_df: pd.DataFrame = dataset.data_as_pandas

Check out the documentation here.

February 28, 2023

Deployment Build Logs

Chalk now provides access to build and boot logs through the Deployments page in the dashboard.

Build Logs

February 16, 2023

Resolver timeouts

Computing features associated with third-party services can be unpredictably slow. Chalk helps you manage such uncertainty by specifying a resolver timeout duration.

Now you can set timeouts for resolvers!

def resolve_australian_credit_score(driver_id: User.driver_id_aus) -> User.credit_score_aus:
    return experian_client.get_score(driver_id)

January 26, 2023

SQL File Resolvers

SQL-integrated resolvers can be completely written in SQL files: no Python required! If you have a SQL source like as follows:

pg = PostgreSQLSource(name='PG')

You can define a resolver in a .chalk.sql file, with comments that detail important metadata. Chalk will process it upon chalk apply as it would any other Python resolver.

-- type: online
-- resolves: user
-- source: PG
-- count: 1
select email, full_name from user_table where id=${}

Check out the documentation here.

January 12, 2023

Improved Logging

Logging on your dashboard has been improved. You can now scroll through more logs, and the formatting is cleaner and easier to use. This view is available for resolvers and resolver runs.

Logs Viewer

January 9, 2023

Pretty Print Online Query Results

Online Query Response objects now support pretty-print in any iPython environment.

Pretty Print Query Response

January 8, 2023

Linux docker containers on M1 Macs

chalkpy has always supported running in docker images using M1’s native arm64 architecture, and now chalkpy==1.12.0 supports most functionality on M1 Macs when run with AMD64 (64 bit Linux) architecture docker images. This is helpful when testing images built for Linux servers that include chalkpy.

January 6, 2023

Chalk has lots of documentation, and finding content is now difficult.

We’ve added docs search!

Documentation search

Try it out by typing cmd-K, or clicking the search button at the top of the table of contents.

September 27, 2022

Tags & Owners as Comments

This update makes several improvements to feature discovery.

Tags and owners are now parsed from the comments preceding the feature definition.

class RocketShip:
    # :tags: team:identity, priority:high
    # :owner:
    velocity: float

Prior to this update, owners and tags needed to be set in the feature(...) function:

class RocketShip:
    velocity: float = feature(
        tags=["team:identity", "priority:high"],

Feel free to choose either mechanism!

July 28, 2022

Auto Id Features

It’s natural to name the primary feature of a feature set id. So why do you always have to specify it? Until now, you needed to write:

class User:
    id: str = feature(primary=True)

Now you don’t have to! If you have a feature class that does not have a feature with the primary field set, but has a feature called id, it will be assigned primary automatically:

class User:
    id: str

The functionality from before sticks around: if you use a field as a primary key with a name other than id, you can keep using it as your primary feature:

class User:
    user_id: str = feature(primary=True)
    # Not really the primary key!
    id: str

July 25, 2022

DataFrame Expressions

The Chalk DataFrame now supports boolean expressions! The Chalk team has worked hard to let you express your DataFrame transformations in natural, idiomatic Python:

  User.first_name == "Eleanor" or ( == "" and
    User.email_status not in {"deactivated", "unverified"}
  ) and User.birthdate is not None

Python experts will note that or, and, is, is not, not in, and not aren’t overload-able. So how did we do this? The answer is AST parsing! A more detailed blog post to follow.

July 22, 2022

Descriptions as Comments

This update makes several improvements to feature discovery.

Descriptions are now parsed from the comments preceding the feature definition. For example, we can document the feature User.fraud_score with a comment above the attribute definition:

class User:
    # 0 to 100 score indicating an identity match.
    # Low scores indicate safer users
    fraud_score: float

Prior to this update, descriptions needed to be set in the feature(...) function:

class UserFeatures:
    fraud_score: float = feature(description="""
           0 to 100 score indicating an identity match.
           Low scores indicate safer users

The description passed to feature(...) takes precedence over the implicit comment description.

Namespace Metadata

You can now set attributes for all features in a namespace!

Here, we assign the tag group:risk and the owner to all features on the feature class. Owners specified at the feature level take precedence (so the owner of is the default whereas the owner of User.flaky_api_result is Tags aggregate, so email has the tags pii and group:risk.

@features(tags="group:risk", owner="")
class User:
    email: str = feature(tags="pii")
    flaky_api_result: str = feature(owner="")

July 14, 2022

Self-Serve Slack Integration

You can configure Chalk to post message to your Slack workspace! You can find the Slack integration tab in the settings page of your dashboard.

Slack integration

Slack can be used as an alert channel or for build notifications.

July 13, 2022

Python 3.8 Support

Chalk’s pip package now supports Python 3.8! With this change, you can use the Chalk package to run online and offline queries in a Python environment with version >= 3.8. Note that your features will still be computed on a runtime with Python version 3.10.

July 8, 2022

Named Integrations

Chalk’s injects environment variables to support data integrations. But what happens when you have two data sources of the same kind? Historically, our recommendation was to create one set of environment variables through an official data source integration, and one set of prefixed environment variables yourself using the generic environment variable support.

With the release of named integrations, you can connect to as many of the same data source as you need! Provide a name at the time of configuring your data source, and reference it in the code directly. Named integrations inject environment variables with the standard names prefixed by the integration name (ie. RISK_PGPORT). The first integration of a given kind will also create the un-prefixed environment variable (ie. both PGPORT and RISK_PGPORT).

June 29, 2022

SOC 2 Report

Chalk is excited to announce the availability of our SOC 2 Type 1 report from Prescient Assurance. Chalk has instituted rigorous controls to ensure the security of customer data and earn the trust of our customers, but we’re always looking for more ways to improve our security posture, and to communicate these steps to our customers. This report is one step along our ongoing path of trust and security.

If you’re interested in reviewing this report, please contact to request a copy.

June 3, 2022

Pandas Integration

You can now convert Chalk’s DataFrame to a pandas.DataFrame and back! Use the methods chalk_df.to_pandas() and .from_pandas(pandas_df).

Migration Sampling

The 1.4.1 release of the CLI added a parameter --sample to chalk migrate. This flag allows migrations to be run targeting specific sample sets.

Feature/Resolver Health

Added spark lines to the feature and resolver tables which show a quick summary of request counts over the past 24 hours. Added status to feature and resolver tables which show any failing checks related to a feature or resolver.