Datadog OpenFeature Node.js Server Client

This package provides OpenFeature integration for Node.js server environments and is designed exclusively for internal Datadog use. Support is not provided for external organizations or third-party usage.

Standalone Configuration Helpers

Requires Node.js 18 or newer. Fetch and parse rules without initializing a tracer or provider. The customer-facing dd-trace/openfeature entrypoint is a separate follow-up; these examples use the internal package.

import { fetchRulesConfiguration, configurationToString } from '@datadog/openfeature-node-server/rules-based'

// The server distribution channel is the default. Rules do not depend on an evaluation context.
const configuration = await fetchRulesConfiguration({ apiKey, env: 'production' })

// For browser bootstrap data, explicitly fetch client-distributed rules.
const clientConfiguration = await fetchRulesConfiguration({
  distributionChannel: 'client',
  clientToken,
  env: 'production',
})
const wire = configurationToString(clientConfiguration)
// Pass wire through the framework's safe SSR data serializer, not raw inline HTML.

Only forward client-distributed configuration to the browser. Serialization does not remove server-only flags. The client endpoint's access controls and opt-in requirements still apply.

Initialize the browser provider from the serialized configuration:

import { configurationFromString, DatadogCoreProvider } from '@datadog/openfeature-browser/rules-based'
import { OpenFeature } from '@openfeature/web-sdk'

const provider = new DatadogCoreProvider()
provider.setConfiguration(configurationFromString(wire))
await OpenFeature.setProviderAndWait(provider, context)

The returned FlagsConfiguration is not the legacy UFC JSON accepted by DatadogNodeServerProvider.setConfiguration(). The existing Node provider is unchanged, and importing it from the root entrypoint does not load the protobuf decoder.

Fetch Options and Errors

• distributionChannel selects the configuration channel to fetch, not where the helper runs. It defaults to server; use client when preparing configuration for browser or mobile SDKs.
• site defaults to datadoghq.com.
• fetch overrides global Fetch. Custom transports must honor signal and redirect: 'manual'; redirects are rejected to protect credentials.
• timeoutMs defaults to 5000 and covers the request and response-body read. signal supports caller cancellation and earlier deadlines.
• Failures throw ConfigurationFetchError with a code and, for HTTP errors, status. Timeouts use timeout; other caller cancellations use cancelled.

Applications own retries, polling, storage, tracking, and fallback.

End-user license agreement

https://www.datadoghq.com/legal/eula