google-adk-kotlin-core/com.google.adk.kt.models/CacheMetadata

CacheMetadata

data class CacheMetadata(val fingerprint: String, val contentsCount: Int, val cacheName: String? = null, val expireTime: Long? = null, val invocationsUsed: Int? = null, val createdAt: Long? = null)

Metadata for the context cache associated with LLM responses.

This stores cache identification, usage tracking, and lifecycle information for a particular cache instance. It can be in one of two states:

Active cache state: cacheName is set and expireTime, invocationsUsed, and createdAt are populated.
Fingerprint-only state: cacheName is null and only fingerprint and contentsCount are set, used for prefix matching before a cache exists.

Token counts (cached and total) are available in LlmResponse.usageMetadata and should be accessed from there to avoid duplication.

Constructors

CacheMetadata

constructor(fingerprint: String, contentsCount: Int, cacheName: String? = null, expireTime: Long? = null, invocationsUsed: Int? = null, createdAt: Long? = null)

Types

Builder

class Builder

Fluent builder for CacheMetadata, provided primarily for Java callers. Any property left unset falls back to the same default as the constructor.

Companion

object Companion

Properties

cacheName

val cacheName: String?

Full resource name of the cached content (e.g. projects/123/locations/us-central1/cachedContents/456). null when no active cache exists.

contentsCount

val contentsCount: Int

Number of contents. When an active cache exists this is the count of cached contents; otherwise it is the count of the cacheable content prefix used for fingerprinting. Must be non-negative.

createdAt

val createdAt: Long?

Epoch milliseconds when the cache was created. null when no active cache exists.

expireSoon

val expireSoon: Boolean

Whether the cache will expire within EXPIRY_BUFFER. Always false for fingerprint-only metadata (which has no expireTime).

expireTime

val expireTime: Long?

Epoch milliseconds when the cache expires. null when no active cache exists.

fingerprint

val fingerprint: String

Hash of the cacheable contents (system instruction + tools + contents). Always present for prefix matching.

invocationsUsed

val invocationsUsed: Int?

Number of invocations this cache has been used for. null when no active cache exists. Must be non-negative when set.

isActive

val isActive: Boolean

Whether this metadata refers to an active cache, as opposed to a fingerprint-only state.

Functions

toString

open override fun toString(): String