Chalk Elixir

Official Elixir client for Chalk Online Queries. This library provides an easy way to integrate with Chalk's API for feature computation and serving.

Installation

Add chalk_elixir to your list of dependencies in mix.exs:

def deps do
  [
    {:chalk_elixir, "~> 0.0.12"}
  ]
end

Usage

Basic Query

Online queries are executed by calling Chalk.Query.online/2 and passing inputs and expected outputs as described in the Chalk API documentation.

{:ok, response} = Chalk.Query.online(%{
  inputs: %{
    "user.id": 1
  },
  outputs: [
    "user.id",
    "user.email",
    "user.credit_score"
  ]
})

Advanced Options

The query can include additional options:

{:ok, response} = Chalk.Query.online(%{
  inputs: %{
    "user.id": 1
  },
  outputs: [
    "user.id",
    "user.email",
    "user.credit_score"
  ],
  staleness: %{
    "user.credit_score": "1d" # Allow data up to 1 day old
  },
  context: %{
    environment: "production",
    tags: ["high-priority"]
  },
  query_name: "user_profile_query" # For telemetry and observability
})

Response Structure

The response contains data, errors, and metadata:

%Chalk.Query.OnlineQueryResponse{
  data: [
    %Chalk.Query.FeatureResult{
      field: "user.id",
      value: 1,
      meta: %Chalk.Query.FeatureMeta{...}
    },
    %Chalk.Query.FeatureResult{
      field: "user.email",
      value: "[email protected]",
      meta: %Chalk.Query.FeatureMeta{...}
    },
    ...
  ],
  errors: [...],
  meta: %Chalk.Query.QueryMeta{...}
}

Authentication

The Chalk client supports two authentication methods:

Environment Variables

Set the following environment variables:

CHALK_CLIENT_ID=your_client_id
CHALK_CLIENT_SECRET=your_client_secret

Optionally, you can set a default deployment:

DEPLOYMENT_ID=your_deployment_id

Explicit Credentials

Pass credentials directly to the client:

Chalk.Query.online(
  %{
    inputs: %{
      "user.id": 1
    },
    outputs: [
      "user.id"
    ]
  },
  %{    
    client_id: "your_client_id",
    secret: "your_client_secret",
    deployment_id: "your_deployment_id" # Optional
  }
)

Credentials can be generated on the Chalk dashboard or via API.

Documentation

For detailed documentation, visit:

• Hex docs
• Chalk API documentation

Development

Running Tests

mix test

Linting

mix dialyzer
mix credo

License

This project is licensed under the Apache 2.0 License - see the LICENSE file for details.