README

OpenFeature provider for Featureflip, backed by the Featureflip PHP server SDK. Use the vendor-neutral OpenFeature API while Featureflip serves your flags.

Installation

composer require featureflip/featureflip-openfeature

Composer resolves the latest compatible release, so no version is pinned here.

Quickstart

Unlike the Java, .NET and Go providers, there is no SDK-key constructor — build a FeatureflipClient yourself and pass it in:

use Featureflip\FeatureflipClient;
use Featureflip\Config;
use Featureflip\OpenFeature\FeatureflipProvider;
use OpenFeature\OpenFeatureAPI;

$client = FeatureflipClient::get('your-server-sdk-key', new Config(
    cache: $psrCache,
    httpClient: $psrHttpClient,
    requestFactory: $psrRequestFactory,
    streamFactory: $psrStreamFactory,
));

OpenFeatureAPI::getInstance()->setProvider(new FeatureflipProvider($client));

$enabled = OpenFeatureAPI::getInstance()
    ->getClient()
    ->getBooleanValue('new-checkout', false, $context);

The PHP SDK's core requires caller-supplied PSR-18, PSR-17 and PSR-16 implementations and throws without them, so a key-only constructor would have to choose an HTTP client and a cache on the application's behalf. Passing the client in is also the idiomatic PHP shape — it is a service-container object, and an application evaluating flags through both the SDK directly and through OpenFeature should share one.

The provider never closes the client it is given: the caller owns it and is responsible for calling $client->close() at shutdown.

Context mapping

OpenFeature context	Featureflip context
`targetingKey`	both `user_id` and `userId` (the latter is the rollout bucketing field)
Any other attribute	Passed through unchanged
A `DateTime`-valued attribute	Rendered as ISO-8601

The targeting key is written under both spellings because the Featureflip PHP SDK resolves a condition's attribute by exact key, with no aliasing between user_id and userId — writing both is what lets a targeting rule against either spelling resolve. Both hold the same string, so a percentage rollout still has exactly one bucketing identity.

An explicit userId or user_id attribute takes precedence over targetingKey and is passed through exactly as you supplied it, with no alias added: the caller naming one is a stronger signal than the framework supplying the other. targetingKey itself is never copied into the attribute bag under its own name.

OpenFeature's Attributes bag may hold a DateTime, which no other SDK's context type can. Every SDK gates its date-comparison rules on the ISO grammar, so a DateTime left as an object would stringify unpredictably (or not at all) and silently match no date rule — the provider converts it for you, recursing into nested arrays.

Evaluation reasons

Featureflip reason	OpenFeature reason
`RULE_MATCH`	`TARGETING_MATCH`
`FALLTHROUGH`	`DEFAULT`
`FLAG_DISABLED`	`DISABLED`
`PREREQUISITE_FAILED`	`PREREQUISITE_FAILED` (custom)
`FLAG_NOT_FOUND`	`ERROR` + `FLAG_NOT_FOUND`
`ERROR`	`ERROR` + `GENERAL`

No standard OpenFeature reason models an unmet prerequisite. Reasons are open strings, so the provider surfaces PREREQUISITE_FAILED verbatim rather than mislabelling it as DEFAULT or DISABLED.

On an error reason the provider returns your default value, never the flag's off-variation value — that value can be wrong-typed (a prerequisite chain past the depth limit, or an errored prerequisite), and the caller's default is what the OpenFeature error contract prescribes.

Type handling

Featureflip does not type-check a flag's value against the accessor you call, so the provider enforces OpenFeature's TYPE_MISMATCH contract itself. A mismatched read returns your default with reason ERROR and error code TYPE_MISMATCH.

Accessor	Accepts
`resolveBooleanValue`	booleans only
`resolveStringValue`	strings only
`resolveIntegerValue`	integers, and whole-number floats (`1.0`)
`resolveFloatValue`	any JSON number, integers included
`resolveObjectValue`	objects and arrays only — not strings

A whole-number float satisfying an integer read is narrowed to a real int before being returned. Without that narrowing the OpenFeature client's own ValueTypeValidator rejects the float, and the client hands you your default value back with reason ERROR and error code GENERAL — a silent wrong answer rather than a loud failure, which is why the narrowing is required rather than cosmetic.

Limitations

No provider events. The open-feature/sdk PHP package has no provider events API at all (no PROVIDER_READY/PROVIDER_CONFIGURATION_CHANGED equivalent to subscribe to, unlike the Node and Python providers). Flag changes are therefore picked up passively, on the underlying SDK's poll interval, rather than pushed to your application — there is nothing to add a listener to.
No flag metadata at this version. The released open-feature/sdk (^2.3, currently 2.3.0) has no flag-metadata API — ResolutionDetailsBuilder has no withMetadata(). ruleId and prerequisiteKey are therefore not exposed; they will be added once the floor moves to a release that supports it.

License

Apache-2.0

featureflip / featureflip-openfeature

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