diff --git a/effects/const.ts b/effects/const.ts
index d366cd168..e83ace124 100644
--- a/effects/const.ts
+++ b/effects/const.ts
@@ -2,8 +2,8 @@ import * as Z from "../deps/zones.ts";
 import * as rpc from "../rpc/mod.ts";
 import * as U from "../util/mod.ts";
 import { codec } from "./core/codec.ts";
-import { decoded } from "./core/decoded.ts";
 import { deriveCodec } from "./core/deriveCodec.ts";
+import * as e$ from "./core/scale.ts";
 import { constMetadata, metadata, palletMetadata } from "./metadata.ts";
 
 export function const_<Client extends Z.$<rpc.Client>>(client: Client) {
@@ -23,7 +23,7 @@ export function const_<Client extends Z.$<rpc.Client>>(client: Client) {
     const entryValueTypeI = constMetadata_.access("ty").access("id");
     const constValue = constMetadata_.access("value");
     const $const = codec(deriveCodec_, entryValueTypeI);
-    return decoded($const, constValue, "value").zoned("Const");
+    return e$.decoded($const, constValue, "value").zoned("Const");
   };
 }
 Object.defineProperty(const_, "name", {
diff --git a/effects/core/$key.ts b/effects/core/$key.ts
deleted file mode 100644
index 13ec2412f..000000000
--- a/effects/core/$key.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import * as Z from "../../deps/zones.ts";
-import * as M from "../../frame_metadata/mod.ts";
-
-export const $key = Z.call.fac((
-  deriveCodec: M.DeriveCodec,
-  pallet: M.Pallet,
-  storageEntry: M.StorageEntry,
-) => {
-  return M.$storageKey({
-    deriveCodec,
-    pallet,
-    storageEntry,
-  });
-});
diff --git a/effects/core/decoded.ts b/effects/core/decoded.ts
deleted file mode 100644
index 9cc0afde1..000000000
--- a/effects/core/decoded.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-import * as $ from "../../deps/scale.ts";
-import * as Z from "../../deps/zones.ts";
-
-export function decoded<
-  Codec extends Z.$<$.Codec<unknown>>,
-  Encoded extends Z.$<Uint8Array>,
-  Key extends Z.$<string>,
->(
-  codec: Codec,
-  encoded: Encoded,
-  key: Key,
-) {
-  return Z.call(
-    Z.ls(codec, encoded, key),
-    function decodedImpl([codec, encoded, key]): Record<Z.T<Key>, any> {
-      return { [key]: codec.decode(encoded) } as any;
-    },
-  );
-}
diff --git a/effects/core/hex.ts b/effects/core/hex.ts
deleted file mode 100644
index bce33905f..000000000
--- a/effects/core/hex.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import * as Z from "../../deps/zones.ts";
-import * as U from "../../util/mod.ts";
-
-export const hexEncode = Z.call.fac(U.hex.encode);
-export const hexDecode = Z.call.fac(U.hex.decode);
diff --git a/effects/core/option.ts b/effects/core/option.ts
new file mode 100644
index 000000000..2efbdeb93
--- /dev/null
+++ b/effects/core/option.ts
@@ -0,0 +1,11 @@
+import * as Z from "../../deps/zones.ts";
+
+// TODO: move this into zones
+export function option<Target, UseResult>(
+  target: Target,
+  use: (resolved: NonNullable<Z.T<Target>>) => UseResult,
+): Z.Effect<undefined | Exclude<UseResult, Error>, Z.E<Target> | Extract<UseResult, Error>> {
+  return Z.call(target, (resolved) => {
+    return resolved ? use(resolved) : undefined;
+  });
+}
diff --git a/effects/core/scale.ts b/effects/core/scale.ts
new file mode 100644
index 000000000..49ea20092
--- /dev/null
+++ b/effects/core/scale.ts
@@ -0,0 +1,35 @@
+import * as $ from "../../deps/scale.ts";
+import * as Z from "../../deps/zones.ts";
+
+export function decoded<
+  Codec extends Z.$<$.Codec<unknown>>,
+  Encoded extends Z.$<Uint8Array>,
+  Key extends Z.$<PropertyKey>,
+>(
+  codec: Codec,
+  encoded: Encoded,
+  key: Key,
+) {
+  return Z.call(
+    Z.ls(codec, encoded, key),
+    function decodedImpl([codec, encoded, key]): Record<Z.T<Key>, any> {
+      return { [key]: codec.decode(encoded) } as any;
+    },
+  );
+}
+
+// TODO: eventually, utilize `V` to toggle runtime validation
+export function encoded<Codec extends Z.$<$.Codec<any>>, Decoded>(
+  codec: Codec,
+  decoded: Decoded,
+  isAsync?: boolean,
+) {
+  return Z.call(Z.ls(codec, decoded, isAsync), function encodedImpl([codec, decoded]) {
+    try {
+      $.assert(codec, decoded);
+    } catch (e) {
+      return e as $.ScaleAssertError;
+    }
+    return codec[isAsync ? "encodeAsync" : "encode"](decoded);
+  });
+}
diff --git a/effects/core/storageKey.ts b/effects/core/storageKey.ts
deleted file mode 100644
index 5fea34201..000000000
--- a/effects/core/storageKey.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import * as $ from "../../deps/scale.ts";
-import * as Z from "../../deps/zones.ts";
-import * as U from "../../util/mod.ts";
-
-export const storageKey = Z.call.fac((
-  $storageKey: $.Codec<unknown[]>,
-  ...keys: unknown[]
-) => {
-  return U.hex.encode($storageKey.encode(keys)) as U.Hex;
-});
diff --git a/effects/entryRead.ts b/effects/entryRead.ts
index 7f8a4006d..0c79b2994 100644
--- a/effects/entryRead.ts
+++ b/effects/entryRead.ts
@@ -3,10 +3,8 @@ import * as rpc from "../rpc/mod.ts";
 import * as U from "../util/mod.ts";
 import { $storageKey } from "./core/$storageKey.ts";
 import { codec } from "./core/codec.ts";
-import { decoded } from "./core/decoded.ts";
 import { deriveCodec } from "./core/deriveCodec.ts";
-import { hexDecode } from "./core/hex.ts";
-import { storageKey } from "./core/storageKey.ts";
+import * as e$ from "./core/scale.ts";
 import { entryMetadata, metadata, palletMetadata } from "./metadata.ts";
 import { state } from "./rpc/known.ts";
 
@@ -27,10 +25,11 @@ export function entryRead<Client extends Z.$<rpc.Client>>(client: Client) {
     const palletMetadata_ = palletMetadata(metadata_, palletName);
     const entryMetadata_ = entryMetadata(palletMetadata_, entryName);
     const $storageKey_ = $storageKey(deriveCodec_, palletMetadata_, entryMetadata_);
-    const storageKey_ = storageKey($storageKey_, ...keys);
-    const storageValueHex = state.getStorage(client)(storageKey_, blockHash);
+    const storageKey = Z.call(e$.encoded($storageKey_, Z.ls(...keys)), U.hex.encode);
+    const storageBytesHex = state.getStorage(client)(storageKey, blockHash);
+    const storageBytes = Z.call(storageBytesHex, U.hex.decode);
     const entryValueTypeI = entryMetadata_.access("value");
     const $entry = codec(deriveCodec_, entryValueTypeI);
-    return decoded($entry, hexDecode(storageValueHex), "value").zoned("EntryRead");
+    return e$.decoded($entry, storageBytes, "value").zoned("EntryRead");
   };
 }
diff --git a/effects/entryWatch.ts b/effects/entryWatch.ts
index 22e1bd98d..907e62a5e 100644
--- a/effects/entryWatch.ts
+++ b/effects/entryWatch.ts
@@ -5,11 +5,11 @@ import * as U from "../util/mod.ts";
 import { $storageKey } from "./core/$storageKey.ts";
 import { codec } from "./core/codec.ts";
 import { deriveCodec } from "./core/deriveCodec.ts";
-import { storageKey } from "./core/storageKey.ts";
+import * as e$ from "./core/scale.ts";
 import { entryMetadata, metadata, palletMetadata } from "./metadata.ts";
 import { state } from "./rpc/known.ts";
 
-export type WatchEntryEvent = [key?: U.Hex, value?: unknown];
+export type WatchEntryEvent = [key?: unknown, value?: unknown];
 
 export function entryWatch<Client extends Z.$<rpc.Client>>(client: Client) {
   return <
@@ -30,9 +30,9 @@ export function entryWatch<Client extends Z.$<rpc.Client>>(client: Client) {
     const entryValueTypeI = entryMetadata_.access("value");
     const $entry = codec(deriveCodec_, entryValueTypeI);
     const storageKeys = Z.call(
-      storageKey($storageKey_, ...keys.length ? [keys] : []),
-      function wrapWithList(v) {
-        return [v];
+      e$.encoded($storageKey_, keys.length ? [keys] : []),
+      function hexEncodeAndWrapWithList(v) {
+        return [U.hex.encode(v)];
       },
     );
     const listenerMapped = Z.call(Z.ls($entry, listener), ([$entry, listener]) => {
@@ -40,8 +40,13 @@ export function entryWatch<Client extends Z.$<rpc.Client>>(client: Client) {
         this: rpc.ClientSubscribeContext,
         changeset: known.StorageChangeSet,
       ) {
+        // TODO: in some cases there might be keys to decode
+        // key ? $storageKey.decode(U.hex.decode(key)) : undefined
+        const getKey = (key: known.Hex) => {
+          return key;
+        };
         const changes: WatchEntryEvent[] = changeset.changes.map(([key, val]) => {
-          return [key, val ? $entry.decode(U.hex.decode(val)) : undefined];
+          return [getKey(key), val ? $entry.decode(U.hex.decode(val)) : undefined];
         });
         listener.apply(this, [changes]);
       };
diff --git a/effects/extrinsic.ts b/effects/extrinsic.ts
index cc2d9d489..3370ed793 100644
--- a/effects/extrinsic.ts
+++ b/effects/extrinsic.ts
@@ -8,7 +8,8 @@ import * as U from "../util/mod.ts";
 import { const as const_ } from "./const.ts";
 import { $extrinsic } from "./core/$extrinsic.ts";
 import { deriveCodec } from "./core/deriveCodec.ts";
-import { hexDecode } from "./core/hex.ts";
+import { option } from "./core/option.ts";
+import * as e$ from "./core/scale.ts";
 import { metadata } from "./metadata.ts";
 import { author, chain, system } from "./rpc/known.ts";
 
@@ -43,19 +44,22 @@ export class SignedExtrinsic<
   Props extends Z.Rec$<ExtrinsicProps>,
   Sign extends Z.$<M.SignExtrinsic>,
 > {
+  props;
   extrinsic;
 
-  constructor(readonly props_: Props, readonly sign: Sign) {
-    const props = props_ as Z.Rec$Access<Props>;
-    const metadata_ = metadata(props.client)();
+  constructor(props_: Props, readonly sign: Sign) {
+    this.props = props_ as Z.Rec$Access<Props>;
+    const metadata_ = metadata(this.props.client)();
     const deriveCodec_ = deriveCodec(metadata_);
-    const addrPrefix = const_(props.client)("System", "SS58Prefix").access("value").as<number>();
+    const addrPrefix = const_(this.props.client)("System", "SS58Prefix")
+      .access("value").as<number>();
     const $extrinsic_ = $extrinsic(deriveCodec_, metadata_, this.sign, addrPrefix);
-    const versions = const_(props.client)("System", "Version").access("value");
+    const versions = const_(this.props.client)("System", "Version").access("value");
     const specVersion = versions.access("spec_version").as<number>();
     const transactionVersion = versions.access("transaction_version").as<number>();
+    // TODO: create match effect in zones and use here
     const senderSs58 = Z.call(
-      Z.ls(addrPrefix, props.sender),
+      Z.ls(addrPrefix, this.props.sender),
       function senderSs58([addrPrefix, sender]) {
         switch (sender.type) {
           case "Id": {
@@ -68,79 +72,45 @@ export class SignedExtrinsic<
         }
       },
     );
-    const nonce = system.accountNextIndex(props.client)(senderSs58);
-    const genesisHash = hexDecode(chain.getBlockHash(props.client)(0));
-    const checkpointHash = props.checkpoint
-      ? Z.call(props.checkpoint, function checkpointOrUndef(v) {
-        return v ? U.hex.decode(v) : v;
-      })
+    const nonce = system.accountNextIndex(this.props.client)(senderSs58);
+    const genesisHashBytes = chain.getBlockHash(this.props.client)(0);
+    const genesisHash = Z.call(genesisHashBytes, U.hex.decode);
+    const checkpointHash = this.props.checkpoint
+      ? option(this.props.checkpoint, U.hex.decode)
       : genesisHash;
-    this.extrinsic = Z.call(
-      Z.ls(
-        $extrinsic_,
-        props.sender,
-        props.methodName,
-        props.palletName,
-        specVersion,
-        transactionVersion,
-        nonce,
-        genesisHash,
-        props.args,
-        checkpointHash,
-        props.tip,
-        props.mortality,
-      ),
-      async function formExtrinsicHex([
-        $extrinsic,
-        sender,
-        methodName,
-        palletName,
-        specVersion,
-        transactionVersion,
-        nonce,
-        genesisHash,
-        args,
-        checkpoint,
-        tip,
-        mortality,
-      ]) {
-        const extrinsicBytes = await $extrinsic.encodeAsync({
-          protocolVersion: 4, // TODO: grab this from elsewhere
-          palletName,
-          methodName,
-          args,
-          signature: {
-            address: sender,
-            extra: [
-              mortality
-                ? {
-                  type: "Mortal",
-                  value: mortality,
-                }
-                : { type: "Immortal" },
-              nonce,
-              tip || 0,
-            ],
-            additional: [specVersion, transactionVersion, checkpoint, genesisHash],
-          },
-        });
-        return U.hex.encode(extrinsicBytes);
-      },
-    );
+    const $extrinsicProps = Z.rec({
+      protocolVersion: 4,
+      palletName: this.props.palletName,
+      methodName: this.props.methodName,
+      args: this.props.args,
+      signature: Z.rec({
+        address: this.props.sender,
+        extra: Z.ls(
+          this.props.mortality
+            ? Z.rec({ type: "Mortal", value: this.props.mortality })
+            : { type: "Immortal" },
+          nonce,
+          this.props.tip || 0,
+        ),
+        additional: Z.ls(specVersion, transactionVersion, checkpointHash, genesisHash),
+      }),
+    });
+    this.extrinsic = Z.call(e$.encoded($extrinsic_, $extrinsicProps, true), U.hex.encode);
   }
 
   watch<Listener extends Z.$<U.Listener<known.TransactionStatus, rpc.ClientSubscribeContext>>>(
     listener: Listener,
   ) {
-    const subscriptionId = author.submitAndWatchExtrinsic(
-      this.props_.client as Props["client"],
-    )([this.extrinsic], listener);
-    return author.unwatchExtrinsic(this.props_.client as Props["client"])(subscriptionId)
+    const subscriptionId = author.submitAndWatchExtrinsic(this.props.client)(
+      [this.extrinsic],
+      listener,
+    );
+    return author.unwatchExtrinsic(this.props.client)(subscriptionId)
       .zoned("ExtrinsicWatch");
   }
 
   get sent() {
-    return author.submitExtrinsic(this.props_.client as Props["client"])(this.extrinsic)
+    return author.submitExtrinsic(this.props.client)(this.extrinsic)
       .zoned("ExtrinsicSent");
   }
 }
diff --git a/effects/keyPageRead.ts b/effects/keyPageRead.ts
index dcd4ca282..4d49af8aa 100644
--- a/effects/keyPageRead.ts
+++ b/effects/keyPageRead.ts
@@ -1,10 +1,9 @@
 import * as Z from "../deps/zones.ts";
 import * as rpc from "../rpc/mod.ts";
 import * as U from "../util/mod.ts";
-import { $key } from "./core/$key.ts";
 import { $storageKey } from "./core/$storageKey.ts";
 import { deriveCodec } from "./core/deriveCodec.ts";
-import { storageKey } from "./core/storageKey.ts";
+import * as e$ from "./core/scale.ts";
 import { mapMetadata, metadata, palletMetadata } from "./metadata.ts";
 import { state } from "./rpc/known.ts";
 
@@ -25,22 +24,20 @@ export function keyPageRead<Client extends Z.$<rpc.Client>>(client: Client) {
     const palletMetadata_ = palletMetadata(metadata_, palletName);
     const entryMetadata_ = mapMetadata(palletMetadata_, entryName);
     const $storageKey_ = $storageKey(deriveCodec_, palletMetadata_, entryMetadata_);
-    const startKey = start ? storageKey($storageKey_, start) : undefined;
-    const storageKey_ = storageKey($storageKey_);
+    const storageKey = Z.call(e$.encoded($storageKey_, []), U.hex.encode);
+    const startKey = start ? Z.call(e$.encoded($storageKey_, []), U.hex.encode) : undefined;
     const keysEncoded = state.getKeysPaged(client)(
-      storageKey_,
+      storageKey,
       count,
       startKey,
       blockHash as Rest[1],
     );
-    const $key_ = $key(deriveCodec_, palletMetadata_, entryMetadata_);
-    return Z.call(
-      Z.ls($key_, keysEncoded),
-      function keysDecodedImpl([$key, keysEncoded]) {
+    return Z
+      .call(Z.ls($storageKey_, keysEncoded), function keysDecodedImpl([$key, keysEncoded]) {
         return keysEncoded.map((keyEncoded: U.Hex) => {
           return $key.decode(U.hex.decode(keyEncoded));
         });
-      },
-    ).zoned("KeyPageRead");
+      })
+      .zoned("KeyPageRead");
   };
 }
diff --git a/effects/metadata.ts b/effects/metadata.ts
index 26b58f35e..7b5874776 100644
--- a/effects/metadata.ts
+++ b/effects/metadata.ts
@@ -5,6 +5,7 @@ import * as rpc from "../rpc/mod.ts";
 import * as U from "../util/mod.ts";
 import { state } from "./rpc/known.ts";
 
+// TODO: callable object so that one doesn't need the extra parens when not specifying block hash?
 export function metadata<Client extends Z.$<rpc.Client>>(client: Client) {
   return <Rest extends [blockHash?: Z.$<U.HexHash | undefined>]>(...[blockHash]: [...Rest]) => {
     return Z.call(