feat: adds allFlagMetadata to clients and provider interface

specification.json

@@ -84,6 +84,13 @@
             "RFC 2119 keyword": "MUST",
             "children": []
         },
+        {
+            "id": "Requirement 1.2.3",
+            "machine_id": "requirement_1_2_3",
+            "content": "The client interface MUST define a `all flag metadata` member or accessor, containing a `flags` field or accessor which is a collection of flag metadata, from the provider.",
+            "RFC 2119 keyword": "MUST",
+            "children": []
+        },
         {
             "id": "Condition 1.3.1",
             "machine_id": "condition_1_3_1",
@@ -358,6 +365,13 @@
             "RFC 2119 keyword": "MUST",
             "children": []
         },
+        {
+            "id": "Requirement 2.1.2",
+            "machine_id": "requirement_2_1_2",
+            "content": "The provider MAY define an `all flag metadata` field or accessor, containing a `flags` field or accessor which is a collection of flag metadata, identifying all available flag keys in the provider.",
+            "RFC 2119 keyword": "MAY",
+            "children": []
+        },
         {
             "id": "Requirement 2.2.1",
             "machine_id": "requirement_2_2_1",

specification/sections/01-flag-evaluation.md

@@ -65,7 +65,7 @@ This function not only sets the provider, but ensures that the provider is ready
 // default provider
 OpenFeatureAPI.getInstance().setProviderAndWait(myprovider); // this method blocks until the provider is ready or in error
 // client uses the default provider
-Client client = OpenFeatureAPI.getInstance().getClient(); 
+Client client = OpenFeatureAPI.getInstance().getClient();
 
 // provider associated with domain-1
 OpenFeatureAPI.getInstance().setProviderAndWait('domain-1', myprovider); // this method blocks until the provider is ready or in error
@@ -171,6 +171,16 @@ client.getMetadata().getDomain(); // "domain-1"
 In previous drafts, this property was called `name`.
 For backwards compatibility, implementations should consider `name` an alias to `domain`.
 
+#### Requirement 1.2.3
+
+> The client interface **MUST** define a `all flag metadata` member or accessor, containing a `flags` field or accessor which is a collection of flag metadata, from the provider.
+
+```typescript
+client.getAllFlagMetadata() // { flags: [{"key": "featureA", "type": "boolean"}, {"key": "featureB", "type": "string"}] }
+```
+
+This may return a language-idiomatic way of describing the absence of a value if the provider does not implement the `allFlagMetadata` member or accessor.
+
 ### 1.3. Flag Evaluation
 
 [![hardening](https://img.shields.io/static/v1?label=Status&message=hardening&color=yellow)](https://github.com/open-feature/spec/tree/main/specification#hardening)
@@ -506,4 +516,4 @@ see: [error codes](../types.md#error-code), [flag value resolution](./02-provide
 
 The SDK ensures that if the provider's lifecycle methods terminate with an `error code`, that error code is included in any associated error events and returned/thrown errors/exceptions.
 
-see: [error codes](../types.md#error-code)
+see: [error codes](../types.md#error-code)

specification/sections/02-providers.md

@@ -26,6 +26,20 @@ Providers are the "translator" between the flag evaluation calls made in applica
 provider.getMetadata().getName(); // "my-custom-provider"
 ```
 
+#### Requirement 2.1.2
+
+> The provider **MAY** define an `all flag metadata` field or accessor, containing a `flags` field or accessor which is a collection of flag metadata, identifying all available flag keys in the provider.
+
+```typescript
+provider.getAllFlagMetadata(); // { flags: [{"key": "featureA", "type": "boolean"}, {"key": "featureB", "type": "string"}] }
+```
+
+This operation should not be confused with a bulk evaluation of all flags.
+This is an informative operation available to clients for understanding which flag keys are currently available from a provider.
+Example usages include building a debug screen based on available flags and detecting stale flag evaluations.
+For some providers, fetching all flags is an expensive operation. If there is language support, consider implementing this as an asynchronous operation.
+If the provider does not implement this behavior or the flag metadata cannot currently be retrieved due to an error status, the language-idiomatic way of describing the absence of a value can be returned from this method.
+
 ### 2.2 Flag Value Resolution
 
 `Providers` are implementations of the `feature provider` interface, which may wrap vendor SDKs, REST API clients, or otherwise resolve flag values from the runtime environment.

specification/types.md

@@ -26,6 +26,10 @@ A numeric value of unspecified type or size. Implementation languages may furthe
 
 Structured data, presented however is idiomatic in the implementation language, such as JSON or YAML.
 
+### Collection
+
+An unordered list or series of similar data types, presented however is idiomatic in the implementation language.
+
 ### Datetime
 
 A language primitive for representing a date and time, optionally including timezone information. If no timezone is specified, the date and time will be treated as UTC.
@@ -122,9 +126,20 @@ A structure containing the following fields:
 ### Flag Metadata
 
 A structure which supports definition of arbitrary properties, with keys of type `string`, and values of type `boolean`, `string`, or `number`.
+`key` and `type` are reserved properties.
+
+`key` is a required property with a value of type `string`.
+`type` is an optional property with a value of type `string`, indicating which client resolution method should be used to resolve the flag key.
 
 This structure is populated by a provider for use by an [Application Author](./glossary.md#application-author) via the [Evaluation API](./glossary.md#evaluation-api) or an [Application Integrator](./glossary.md#application-integrator) via [hooks](./sections/04-hooks.md).
 
+### Provider Metadata
+
+A structure which carries information about the provider.
+In addition to the defined metadata fields below, arbitrary information can be stored here unique to the provider.
+
+`name` is a required key with a value of type string.
+
 ### Provider Status
 
 An enumeration of possible provider states.