Usage

Basic usage

AWS
Azure

from gateway import TextSource, Verdict
from gateway.aws import AwsClient

client = AwsClient.from_sfn_arn("arn:aws:states:us-east-1:123456789:stateMachine:gateway")

ruling = client.judge(
    claim="Sally is a cat",
    sources=[
        TextSource(id="pet-info", text="I have a cat called Sally."),
        TextSource(id="pet-count", text="I only have one pet."),
    ],
)

print(ruling.verdict)  # Verdict.SUPPORTS

import asyncio
from gateway import TextSource, Verdict
from gateway.azure import AzureClient

client = AzureClient.from_function_app_url(
    "https://yourprefix-func.azurewebsites.net",
    api_key="your-function-key",
)

ruling = asyncio.run(client.judge(
    claim="Sally is a cat",
    sources=[
        TextSource(id="pet-info", text="I have a cat called Sally."),
        TextSource(id="pet-count", text="I only have one pet."),
    ],
))

print(ruling.verdict)  # Verdict.SUPPORTS

The Azure client is async — use await in async code, or asyncio.run() as shown above.

The judge method:

Sends the claim and sources to Gateway
Waits for completion (polls automatically)
Returns a Ruling object with the verdict and evidence

Authentication

AWS
Azure

The AwsClient uses your AWS credentials to invoke the Step Function. Credentials are loaded automatically from:

Environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY)
IAM role (when running on AWS)
AWS credentials file (~/.aws/credentials)

To use a specific profile or region:

import boto3
from gateway.aws import AwsClient

session = boto3.Session(profile_name="my-profile")
client = AwsClient.from_sfn_arn("arn:aws:states:...", session=session)

The AzureClient authenticates with the Function App’s function key, passed directly at construction time:

from gateway.azure import AzureClient

client = AzureClient.from_function_app_url(
    "https://yourprefix-func.azurewebsites.net",
    api_key="your-function-key",
)

The URL and key are available as Terraform outputs after deployment. Retrieve the key with terraform output function_app_default_key.

Sources

Currently, only text sources are supported:

from gateway import TextSource

# With explicit ID (recommended for tracing evidence)
source = TextSource(id="doc-123", text="The sky is blue.")

# Auto-generated ID
source = TextSource.from_text("The sky is blue.")

Types

All types are importable from gateway:

Type	Description
`TextSource`	A plain-text source document
`Ruling`	The result of `client.judge()`
`Statement`	A single statement extracted from the claim
`Influence`	Evidence from a source that influenced a verdict
`TextInfluence`	Evidence from a `TextSource`, includes character spans
`Verdict`	Enum: `SUPPORTS`, `REFUTES`, `NOT_ENOUGH_INFO`

Errors

Errors are raised from gateway.errors:

from gateway.errors import APIError

try:
    ruling = client.judge(claim="...", sources=[...])
except APIError as e:
    print(f"Gateway error: {e}")

Getting Started

SDK

Basic usage

Authentication

Sources

Types

Errors

​Basic usage

​Authentication

​Sources

​Types

​Errors

Basic usage

Authentication

Sources

Types

Errors