Configuration

Everything is configured through the builder passed to AddActionCache.

builder.Services.AddActionCache(options =>
{
    options.UseMemoryCache(memory => memory.SizeLimit = 10_000);
    options.UseRedisCache("localhost:6379");

    options.UseEntryOptions(entry =>
    {
        entry.AbsoluteExpiration = TimeSpan.FromMinutes(5);
        entry.SlidingExpiration  = TimeSpan.FromMinutes(1);
    });

    options.UseOperationTimeout(TimeSpan.FromMilliseconds(250));
    options.UseDistributedSingleFlight();
});

Builder methods

Method	Purpose
`UseMemoryCache(Action<MemoryCacheOptions>)`	Register the in-process backend.
`UseRedisCache(Action<RedisCacheOptions>)`	Register Redis.
`UseRedisCache(string)`	Register Redis from a configuration string.
`UseSqlServerCache(Action<SqlServerCacheOptions>)`	Register SQL Server.
`UseAzureCosmosCache(Action<AzureCosmosCacheOptions>)`	Register Azure Cosmos DB.
`UseEntryOptions(Action<ActionCacheEntryOptions>)`	Default expirations and the key-index lock timeout.
`FailClosed(bool = true)`	Propagate backend failures instead of degrading.
`UseOperationTimeout(TimeSpan)`	Bound a single backend operation.
`UseDistributedSingleFlight(Action<ActionCacheSingleFlightOptions>?)`	Coalesce across instances.
`UseSingleFlightOptions(Action<ActionCacheSingleFlightOptions>)`	Tune coalescing without switching to distributed.
`UsePlaintextKeys()`	Emit readable, reversible keys. Debugging only.
`AddBackend(Action<IServiceCollection>)`	Register a backend of your own.
`AddDistributedLocker(...)`	Supply a distributed lock for a custom backend.

Registration order is chain order — see Layered backends.

ActionCacheEntryOptions

Defaults for every entry, overridable per action on [ActionCache].

Property	Type	Default	Meaning
`AbsoluteExpiration`	`TimeSpan?`	`null`	Lifetime from when the entry is written.
`SlidingExpiration`	`TimeSpan?`	`null`	Idle lifetime, reset on each read.
`LockTimeout`	`TimeSpan`	10s	How long to wait for a namespace key-index lock.

LockTimeout guards the short read-modify-write on a namespace’s key index. It is not the single-flight wait — that is ActionCacheSingleFlightOptions.WaitTimeout, which is held across the origin action and sized differently on purpose.

ActionCacheSingleFlightOptions

Property	Type	Default	Meaning
`LeaseDuration`	`TimeSpan`	30s	How long the leader may hold a key’s lock before others assume it died.
`WaitTimeout`	`TimeSpan`	10s	How long a caller waits before executing uncoalesced.

Validated at startup: both must be positive, and LeaseDuration must exceed WaitTimeout.

Only locks with a time-to-live enforce the lease — that is Redis. See Stampede protection.

ActionCacheResilienceOptions

Set through FailClosed() and UseOperationTimeout().

Property	Type	Default	Meaning
`FailClosed`	`bool`	`false`	Rethrow backend failures instead of degrading.
`OperationTimeout`	`TimeSpan?`	`null`	Abandon a backend operation after this long.

See Resilience.

ActionCache attribute properties

Property	Type	Default
`Namespace`	`string`	required
`AbsoluteExpiration`	`long` (ms)	`0` — none
`SlidingExpiration`	`long` (ms)	`0` — none
`VaryByUser`	`VaryByUserMode`	`Auto`
`VaryByHeader`	`string?`	`null`
`VaryByQuery`	`string?`	`null`
`VaryByClaim`	`string?`	`null`
`SingleFlight`	`bool`	`true`

[ActionCacheEviction] and [ActionCacheRefresh] take Namespace only.

ActionCacheEndpointOptions

The Minimal API equivalent, configured through WithActionCache(ns, options => ...).

Property	Type	Default
`AbsoluteExpiration`	`TimeSpan?`	`null` — none
`SlidingExpiration`	`TimeSpan?`	`null` — none
`VaryByUser`	`VaryByUserMode`	`Auto`
`VaryByHeader`	`string?`	`null`
`VaryByQuery`	`string?`	`null`
`VaryByClaim`	`string?`	`null`
`SingleFlight`	`bool`	`true`

The expirations are TimeSpan? where the attribute takes long milliseconds: an attribute argument must be a compile-time constant, and a builder argument need not be.

The delegate runs once at registration, not per request — the options describe the endpoint, so re-running caller code on every request would only make an expensive lambda an expensive endpoint.

WithActionCacheEviction and WithActionCacheRefresh take a namespace only, matching their attributes. See Attributes.

Key contributors

builder.Services.AddActionCacheKeyContributor<TenantKeyContributor>();

See Vary-by.

Diagnostics names

Constant	Value
`ActionCacheDiagnostics.MeterName`	`ActionCache`
`ActionCacheDiagnostics.ActivitySourceName`	`ActionCache`