diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/each/SequenceKEach.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/each/SequenceKEach.kt
new file mode 100644
index 0000000..23622e4
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/each/SequenceKEach.kt
@@ -0,0 +1,46 @@
+package arrow.optics.extensions.sequence.each
+
+import arrow.core.SequenceK
+import arrow.optics.PTraversal
+import arrow.optics.extensions.SequenceKEach
+
+@JvmName("each")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "Each is being deprecated. Use the instance for Sequence from Traversal's companion object instead.",
+  ReplaceWith(
+    "Traversal.sequence<A>()",
+    "arrow.optics.Traversal", "arrow.optics.sequence"),
+  DeprecationLevel.WARNING
+)
+fun <A> each(): PTraversal<SequenceK<A>, SequenceK<A>, A, A> =
+    arrow.optics.extensions.sequence.each.Sequence
+   .each<A>()
+   .each() as arrow.optics.PTraversal<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val each_singleton: SequenceKEach<Any?> = object : SequenceKEach<Any?> {}
+
+@Deprecated("Receiver Sequence object is deprecated, and it will be removed in 0.13.")
+object Sequence {
+  @Suppress(
+    "UNCHECKED_CAST",
+    "NOTHING_TO_INLINE"
+  )
+  @Deprecated(
+    "Each is being deprecated. Use the instance for Sequence from Traversal's companion object instead.",
+    ReplaceWith(
+      "Traversal.sequence<A>()",
+      "arrow.optics.Traversal", "arrow.optics.sequence"),
+    DeprecationLevel.WARNING
+  )
+  inline fun <A> each(): SequenceKEach<A> = each_singleton as
+      arrow.optics.extensions.SequenceKEach<A>}
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/filterIndex/SequenceKFilterIndex.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/filterIndex/SequenceKFilterIndex.kt
new file mode 100644
index 0000000..08465ce
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/filterIndex/SequenceKFilterIndex.kt
@@ -0,0 +1,49 @@
+package arrow.optics.extensions.sequence.filterIndex
+
+import arrow.core.SequenceK
+import arrow.optics.PTraversal
+import arrow.optics.extensions.SequenceKFilterIndex
+
+@JvmName("filter")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated. Use the exposed function in the instance for Sequence from the companion object of the typeclass instead.",
+  ReplaceWith(
+    "FilterIndex.sequence<A>().filter(p)",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.FilterIndex"
+  ),
+  DeprecationLevel.WARNING
+)
+fun <A> filter(p: Function1<Int, Boolean>): PTraversal<SequenceK<A>, SequenceK<A>, A, A> =
+    arrow.optics.extensions.sequence.filterIndex.Sequence
+   .filterIndex<A>()
+   .filter(p) as arrow.optics.PTraversal<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val filterIndex_singleton: SequenceKFilterIndex<Any?> = object : SequenceKFilterIndex<Any?>
+    {}
+
+@Deprecated("Receiver Sequence object is deprecated, and it will be removed in 0.13.")
+object Sequence {
+  @Suppress(
+    "UNCHECKED_CAST",
+    "NOTHING_TO_INLINE"
+  )
+  @Deprecated(
+    "Typeclass instance have been moved to the companion object of the typeclass.",
+    ReplaceWith(
+      "FilterIndex.sequence<A>()",
+      "arrow.optics.sequence", "arrow.optics.typeclasses.FilterIndex"
+    ),
+    DeprecationLevel.WARNING
+  )
+  inline fun <A> filterIndex(): SequenceKFilterIndex<A> = filterIndex_singleton as
+      arrow.optics.extensions.SequenceKFilterIndex<A>}
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/index/SequenceKIndex.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/index/SequenceKIndex.kt
new file mode 100644
index 0000000..b377732
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequence/index/SequenceKIndex.kt
@@ -0,0 +1,69 @@
+package arrow.optics.extensions.sequence.index
+
+import arrow.core.SequenceK
+import arrow.optics.PLens
+import arrow.optics.POptional
+import arrow.optics.extensions.SequenceKIndex
+
+@JvmName("index")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated. Use the exposed function in the instance for Sequence from the companion object of the typeclass instead.",
+  ReplaceWith(
+    "Index.sequence<A>().index(i)",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+  ),
+  DeprecationLevel.WARNING
+)
+fun <A> index(i: Int): POptional<SequenceK<A>, SequenceK<A>, A, A> =
+    arrow.optics.extensions.sequence.index.Sequence
+   .index<A>()
+   .index(i) as arrow.optics.POptional<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+@JvmName("get")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated, and it will be removed in 0.13.",
+  ReplaceWith(
+    "this compose Index.sequence<A>().index(i)",
+    "arrow.optics.compose", "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+  ),
+  level = DeprecationLevel.WARNING
+)
+operator fun <A, T> PLens<T, T, SequenceK<A>, SequenceK<A>>.get(i: Int): POptional<T, T, A, A> =
+    arrow.optics.extensions.sequence.index.Sequence.index<A>().run {
+  this@get.get<T>(i) as arrow.optics.POptional<T, T, A, A>
+}
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val index_singleton: SequenceKIndex<Any?> = object : SequenceKIndex<Any?> {}
+
+@Deprecated("Receiver Sequence object is deprecated, and it will be removed in 0.13.")
+object Sequence {
+  @Suppress(
+    "UNCHECKED_CAST",
+    "NOTHING_TO_INLINE"
+  )
+  @Deprecated(
+    "Typeclass instance have been moved to the companion object of the typeclass.",
+    ReplaceWith(
+      "Index.sequence<A>()",
+      "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+    ),
+    DeprecationLevel.WARNING
+  )
+  inline fun <A> index(): SequenceKIndex<A> = index_singleton as
+      arrow.optics.extensions.SequenceKIndex<A>}
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek.kt
index f1522b5..a3f22ae 100644
--- a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek.kt
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek.kt
@@ -6,7 +6,6 @@ import arrow.core.k
 import arrow.core.left
 import arrow.core.right
 import arrow.core.toT
-import arrow.extension
 import arrow.optics.Optional
 import arrow.optics.POptional
 import arrow.optics.Traversal
@@ -21,6 +20,13 @@ import arrow.typeclasses.Applicative
  * @receiver [SequenceK.Companion] to make it statically available.
  * @return [Traversal] with source [SequenceK] and focus in every [A] of the source.
  */
+@Deprecated(
+  "SequenceK is being deprecated. Use the instance for Sequence from the companion object of the typeclass.",
+  ReplaceWith(
+    "Traversal.sequence<A>()",
+    "arrow.optics.Traversal", "arrow.optics.sequence"),
+  DeprecationLevel.WARNING
+)
 fun <A> SequenceK.Companion.traversal(): Traversal<SequenceK<A>, A> = object : Traversal<SequenceK<A>, A> {
   override fun <F> modifyF(FA: Applicative<F>, s: SequenceK<A>, f: (A) -> Kind<F, A>): Kind<F, SequenceK<A>> =
     s.traverse(FA, f)
@@ -29,7 +35,12 @@ fun <A> SequenceK.Companion.traversal(): Traversal<SequenceK<A>, A> = object : T
 /**
  * [Each] instance definition for [SequenceK].
  */
-@extension
+@Deprecated(
+  "Each is being deprecated. Use the instance for List from Traversal's companion object instead.",
+  ReplaceWith(
+    "Traversal.sequence<A>()",
+    "arrow.optics.Traversal", "arrow.optics.sequence"),
+  DeprecationLevel.WARNING)
 interface SequenceKEach<A> : Each<SequenceK<A>, A> {
   override fun each(): Traversal<SequenceK<A>, A> =
     SequenceK.traversal()
@@ -38,7 +49,14 @@ interface SequenceKEach<A> : Each<SequenceK<A>, A> {
 /**
  * [FilterIndex] instance definition for [SequenceK].
  */
-@extension
+@Deprecated(
+  "Typeclass interface implementation will not be exposed directly anymore.",
+  ReplaceWith(
+    "FilterIndex.sequence<A>()",
+    "arrow.optics.map", "arrow.optics.typeclasses.FilterIndex"
+  ),
+  DeprecationLevel.WARNING
+)
 interface SequenceKFilterIndex<A> : FilterIndex<SequenceK<A>, Int, A> {
   override fun filter(p: (Int) -> Boolean): Traversal<SequenceK<A>, A> = object : Traversal<SequenceK<A>, A> {
     override fun <F> modifyF(FA: Applicative<F>, s: SequenceK<A>, f: (A) -> Kind<F, A>): Kind<F, SequenceK<A>> = FA.run {
@@ -52,7 +70,14 @@ interface SequenceKFilterIndex<A> : FilterIndex<SequenceK<A>, Int, A> {
 /**
  * [Index] instance definition for [SequenceK].
  */
-@extension
+@Deprecated(
+  "Typeclass interface implementation will not be exposed directly anymore.",
+  ReplaceWith(
+    "Index.sequence<A>()",
+    "arrow.optics.map", "arrow.optics.typeclasses.Index"
+  ),
+  DeprecationLevel.WARNING
+)
 interface SequenceKIndex<A> : Index<SequenceK<A>, Int, A> {
   override fun index(i: Int): Optional<SequenceK<A>, A> = POptional(
     getOrModify = { it.elementAtOrNull(i)?.right() ?: it.left() },
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/each/SequenceKEach.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/each/SequenceKEach.kt
new file mode 100644
index 0000000..e11b1a9
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/each/SequenceKEach.kt
@@ -0,0 +1,44 @@
+package arrow.optics.extensions.sequencek.each
+
+import arrow.core.SequenceK
+import arrow.core.SequenceK.Companion
+import arrow.optics.PTraversal
+import arrow.optics.extensions.SequenceKEach
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val each_singleton: SequenceKEach<Any?> = object : SequenceKEach<Any?> {}
+
+@JvmName("each")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "Each is being deprecated. Use the instance for Sequence from Traversal's companion object instead.",
+  ReplaceWith(
+    "Traversal.sequence<A>()",
+    "arrow.optics.Traversal", "arrow.optics.sequence"),
+  DeprecationLevel.WARNING
+)
+fun <A> each(): PTraversal<SequenceK<A>, SequenceK<A>, A, A> = arrow.core.SequenceK
+   .each<A>()
+   .each() as arrow.optics.PTraversal<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+@Suppress(
+  "UNCHECKED_CAST",
+  "NOTHING_TO_INLINE"
+)
+@Deprecated(
+  "Each is being deprecated. Use the instance for Sequence from Traversal's companion object instead.",
+  ReplaceWith(
+    "Traversal.sequence<A>()",
+    "arrow.optics.Traversal", "arrow.optics.sequence"),
+  DeprecationLevel.WARNING
+)
+inline fun <A> Companion.each(): SequenceKEach<A> = each_singleton as
+    arrow.optics.extensions.SequenceKEach<A>
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/filterIndex/SequenceKFilterIndex.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/filterIndex/SequenceKFilterIndex.kt
new file mode 100644
index 0000000..81407ab
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/filterIndex/SequenceKFilterIndex.kt
@@ -0,0 +1,48 @@
+package arrow.optics.extensions.sequencek.filterIndex
+
+import arrow.core.SequenceK
+import arrow.core.SequenceK.Companion
+import arrow.optics.PTraversal
+import arrow.optics.extensions.SequenceKFilterIndex
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val filterIndex_singleton: SequenceKFilterIndex<Any?> = object : SequenceKFilterIndex<Any?>
+    {}
+
+@JvmName("filter")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated. Use the exposed function in the instance for Sequence from the companion object of the typeclass instead.",
+  ReplaceWith(
+    "FilterIndex.sequence<A>().filter(p)",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.FilterIndex"
+  ),
+  DeprecationLevel.WARNING
+)
+fun <A> filter(p: Function1<Int, Boolean>): PTraversal<SequenceK<A>, SequenceK<A>, A, A> =
+    arrow.core.SequenceK
+   .filterIndex<A>()
+   .filter(p) as arrow.optics.PTraversal<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+@Suppress(
+  "UNCHECKED_CAST",
+  "NOTHING_TO_INLINE"
+)
+@Deprecated(
+  "SequenceK is being deprecated. Use the instance for Sequence from the companion object of the typeclass.",
+  ReplaceWith(
+    "FilterIndex.sequence<A>()",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.FilterIndex"
+  ),
+  DeprecationLevel.WARNING
+)
+inline fun <A> Companion.filterIndex(): SequenceKFilterIndex<A> = filterIndex_singleton as
+    arrow.optics.extensions.SequenceKFilterIndex<A>
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/index/SequenceKIndex.kt b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/index/SequenceKIndex.kt
new file mode 100644
index 0000000..57408c4
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/extensions/sequencek/index/SequenceKIndex.kt
@@ -0,0 +1,67 @@
+package arrow.optics.extensions.sequencek.index
+
+import arrow.core.SequenceK
+import arrow.core.SequenceK.Companion
+import arrow.optics.PLens
+import arrow.optics.POptional
+import arrow.optics.extensions.SequenceKIndex
+
+/**
+ * cached extension
+ */
+@PublishedApi()
+internal val index_singleton: SequenceKIndex<Any?> = object : SequenceKIndex<Any?> {}
+
+@JvmName("index")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated. Use the exposed function in the instance for Sequence from the companion object of the typeclass instead.",
+  ReplaceWith(
+    "Index.sequence<A>().index(i)",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+  ),
+  DeprecationLevel.WARNING
+)
+fun <A> index(i: Int): POptional<SequenceK<A>, SequenceK<A>, A, A> = arrow.core.SequenceK
+   .index<A>()
+   .index(i) as arrow.optics.POptional<arrow.core.SequenceK<A>, arrow.core.SequenceK<A>, A, A>
+
+@JvmName("get")
+@Suppress(
+  "UNCHECKED_CAST",
+  "USELESS_CAST",
+  "EXTENSION_SHADOWED_BY_MEMBER",
+  "UNUSED_PARAMETER"
+)
+@Deprecated(
+  "arrow.optics.extensions package is being deprecated, and it will be removed in 0.13.",
+  ReplaceWith(
+    "this compose Index.sequence<A>().index(i)",
+    "arrow.optics.compose", "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+  ),
+  level = DeprecationLevel.WARNING
+)
+operator fun <A, T> PLens<T, T, SequenceK<A>, SequenceK<A>>.get(i: Int): POptional<T, T, A, A> =
+    arrow.core.SequenceK.index<A>().run {
+  this@get.get<T>(i) as arrow.optics.POptional<T, T, A, A>
+}
+
+@Suppress(
+  "UNCHECKED_CAST",
+  "NOTHING_TO_INLINE"
+)
+@Deprecated(
+  "SequenceK is being deprecated. Use the instance for Sequence from the companion object of the typeclass.",
+  ReplaceWith(
+    "Index.sequence<A>()",
+    "arrow.optics.sequence", "arrow.optics.typeclasses.Index"
+  ),
+  DeprecationLevel.WARNING
+)
+inline fun <A> Companion.index(): SequenceKIndex<A> = index_singleton as
+    arrow.optics.extensions.SequenceKIndex<A>
diff --git a/arrow-optics/src/main/kotlin/arrow/optics/std/sequence.kt b/arrow-optics/src/main/kotlin/arrow/optics/std/sequence.kt
new file mode 100644
index 0000000..e879e0e
--- /dev/null
+++ b/arrow-optics/src/main/kotlin/arrow/optics/std/sequence.kt
@@ -0,0 +1,33 @@
+package arrow.optics
+
+import arrow.Kind
+import arrow.core.k
+import arrow.core.left
+import arrow.core.right
+import arrow.core.toT
+import arrow.optics.typeclasses.FilterIndex
+import arrow.optics.typeclasses.Index
+import arrow.typeclasses.Applicative
+
+fun <A> FilterIndex.Companion.sequence(): FilterIndex<Sequence<A>, Int, A> = FilterIndex { p ->
+  object : Traversal<Sequence<A>, A> {
+    override fun <F> modifyF(FA: Applicative<F>, s: Sequence<A>, f: (A) -> Kind<F, A>): Kind<F, Sequence<A>> =
+      FA.run {
+        s.mapIndexed { index, a -> a toT index }.k().traverse(FA) { (a, j) -> if (p(j)) f(a) else just(a)
+        }
+      }
+  }
+}
+
+fun <A> Index.Companion.sequence(): Index<Sequence<A>, Int, A> = Index { i ->
+  POptional(
+    getOrModify = { it.elementAtOrNull(i)?.right() ?: it.left() },
+    set = { s, a -> s.mapIndexed { index, aa -> if (index == i) a else aa } }
+  )
+}
+
+fun <A> PTraversal.Companion.sequence(): Traversal<Sequence<A>, A> =
+  object : Traversal<Sequence<A>, A> {
+    override fun <F> modifyF(FA: Applicative<F>, s: Sequence<A>, f: (A) -> Kind<F, A>): Kind<F, Sequence<A>> =
+      FA.run { s.k().traverse(FA, f) }
+  }
diff --git a/arrow-optics/src/test/kotlin/arrow/optics/instances/SequenceInstanceTest.kt b/arrow-optics/src/test/kotlin/arrow/optics/instances/SequenceInstanceTest.kt
new file mode 100644
index 0000000..331173e
--- /dev/null
+++ b/arrow-optics/src/test/kotlin/arrow/optics/instances/SequenceInstanceTest.kt
@@ -0,0 +1,66 @@
+package arrow.optics.instances
+
+import arrow.core.Option
+import arrow.core.SequenceK
+import arrow.core.extensions.eq
+import arrow.core.extensions.option.eq.eq
+import arrow.core.extensions.sequencek.eq.eq
+import arrow.core.list
+import arrow.core.test.UnitSpec
+import arrow.core.test.generators.functionAToB
+import arrow.optics.Traversal
+import arrow.optics.sequence
+import arrow.optics.test.laws.OptionalLaws
+import arrow.optics.test.laws.TraversalLaws
+import arrow.optics.typeclasses.FilterIndex
+import arrow.optics.typeclasses.Index
+import arrow.typeclasses.Eq
+import io.kotlintest.properties.Gen
+
+class SequenceInstanceTest : UnitSpec() {
+
+  private fun <A> Gen.Companion.sequence(genA: Gen<A>): Gen<Sequence<A>> = list(genA).map { it.asSequence() }
+
+  private fun <A> sequenceEq(eqA: Eq<A>): Eq<Sequence<A>> = object : Eq<Sequence<A>> {
+    override fun Sequence<A>.eqv(b: Sequence<A>): Boolean =
+      SequenceK.eq(eqA).run { SequenceK(this@eqv).eqv(SequenceK(b)) }
+  }
+
+  init {
+
+    testLaws(
+      TraversalLaws.laws(
+        traversal = Traversal.sequence(),
+        aGen = Gen.sequence(Gen.string()),
+        bGen = Gen.string(),
+        funcGen = Gen.functionAToB(Gen.string()),
+        EQA = sequenceEq(String.eq()),
+        EQOptionB = Option.eq(String.eq()),
+        EQListB = Eq.list(String.eq())
+      )
+    )
+
+    testLaws(
+      TraversalLaws.laws(
+        traversal = FilterIndex.sequence<String>().filter { true },
+        aGen = Gen.sequence(Gen.string()),
+        bGen = Gen.string(),
+        funcGen = Gen.functionAToB(Gen.string()),
+        EQA = sequenceEq(String.eq()),
+        EQListB = Eq.list(String.eq()),
+        EQOptionB = Option.eq(String.eq())
+      )
+    )
+
+    testLaws(
+      OptionalLaws.laws(
+        optionalGen = Gen.int().map { Index.sequence<String>().index(it) },
+        aGen = Gen.sequence(Gen.string()),
+        bGen = Gen.string(),
+        funcGen = Gen.functionAToB(Gen.string()),
+        EQOptionB = Option.eq(String.eq()),
+        EQA = sequenceEq(String.eq())
+      )
+    )
+  }
+}