diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f625621b2..5621d908c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 
 ### Features
 
+- ts: Re-implement `verifiedBuild` using the OtterSec registry (`verify.osec.io`), replacing the defunct `apr.dev` API ([#4522](https://github.com/solana-foundation/anchor/pull/4522)).
 - ts: Add `decodeIdlAccountRaw` ([#4375](https://github.com/solana-foundation/anchor/pull/4375)).
 - cli: Add `--stdout` flag to the `expand` command ([#4400](https://github.com/solana-foundation/anchor/pull/4400)).
 - client: Add versioned tx support ([#4207](https://github.com/solana-foundation/anchor/pull/4207)).
@@ -185,7 +186,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 
 - spl: Update SPL dependencies to latest compatible versions ([#3860](https://github.com/solana-foundation/anchor/pull/3860)).
 - cli: Replace `anchor verify` to use `solana-verify` under the hood, adding automatic installation via AVM, local path support, and future-proof argument passing ([#3768](https://github.com/solana-foundation/anchor/pull/3768)).
-- cli: Upload IDL by default with an option to skip ((#3863)[https://github.com/solana-foundation/anchor/pull/3863]).
+- cli: Upload IDL by default with an option to skip ([#3863](https://github.com/solana-foundation/anchor/pull/3863)).
 - lang: remove Solang ([#3824](https://github.com/solana-foundation/anchor/pull/3824)).
 - cli: remove `anchor publish` command ([#3795](https://github.com/solana-foundation/anchor/pull/3795)).
 
@@ -477,7 +478,7 @@ See the [Anchor 0.30 release notes](https://www.anchor-lang.com/release-notes/0.
 - spl: Fix not being able to deserialize newer token 2022 extensions ([#2876](https://github.com/solana-foundation/anchor/pull/2876)).
 - client: Fix erroneous Cluster websocket ports ([#2690](https://github.com/solana-foundation/anchor/pull/2690)).
 - spl: Remove `solana-program` dependency ([#2900](https://github.com/solana-foundation/anchor/pull/2900)).
-- spl: Make `TokenAccount` and ` Mint` `Copy` ([#2904](https://github.com/solana-foundation/anchor/pull/2904)).
+- spl: Make `TokenAccount` and `Mint` `Copy` ([#2904](https://github.com/solana-foundation/anchor/pull/2904)).
 - ts: Add missing errors ([#2906](https://github.com/solana-foundation/anchor/pull/2906)).
 
 ### Breaking
@@ -822,9 +823,9 @@ See the [Anchor 0.29 release notes](https://www.anchor-lang.com/release-notes/0.
 - lang: Require doc comments when using AccountInfo or UncheckedAccount types ([#1452](https://github.com/solana-foundation/anchor/pull/1452)).
 - lang: add [`error!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.error.html) and [`err!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.err.html) macro and `Result` type ([#1462](https://github.com/solana-foundation/anchor/pull/1462)).
   This change will break most programs. Do the following to upgrade:
-  _ change all `ProgramResult`'s to `Result<()>`
+  _change all `ProgramResult`'s to `Result<()>`
   _ change `#[error]` to `#[error_code]`
-  _ change all `Err(MyError::SomeError.into())` to `Err(error!(MyError::SomeError))` and all `Err(ProgramError::SomeProgramError)` to `Err(ProgramError::SomeProgramError.into())` or `Err(Error::from(ProgramError::SomeProgramError).with_source(source!()))` to provide file and line source of the error (`with_source` is most useful with `ProgramError`s. `error!` already adds source information for custom and anchor internal errors).
+  _change all `Err(MyError::SomeError.into())` to `Err(error!(MyError::SomeError))` and all `Err(ProgramError::SomeProgramError)` to `Err(ProgramError::SomeProgramError.into())` or `Err(Error::from(ProgramError::SomeProgramError).with_source(source!()))` to provide file and line source of the error (`with_source` is most useful with `ProgramError`s. `error!` already adds source information for custom and anchor internal errors).
   _ change all `solana_program::program::invoke()` to `solana_program::program::invoke().map_err(Into::into)` and `solana_program::program::invoke_signed()` to `solana_program::program::invoke_signed().map_err(Into::into)`
 
 ## [0.21.0] - 2022-02-07
diff --git a/Untitled b/Untitled
new file mode 100644
index 0000000000..379fa987e5
--- /dev/null
+++ b/Untitled
@@ -0,0 +1 @@
+ts: Re-implement 
\ No newline at end of file
diff --git a/ts/packages/anchor/src/utils/registry.ts b/ts/packages/anchor/src/utils/registry.ts
index 6e389f541d..86ed5676fe 100644
--- a/ts/packages/anchor/src/utils/registry.ts
+++ b/ts/packages/anchor/src/utils/registry.ts
@@ -1,14 +1,45 @@
 import BN from "bn.js";
+import fetch from "cross-fetch";
 import * as borsh from "@anchor-lang/borsh";
 import { Connection, PublicKey } from "@solana/web3.js";
 
+const OSEC_REGISTRY_URL = "https://verify.osec.io";
+
+export type VerifiedBuild = {
+  is_verified: boolean;
+  message: string;
+  on_chain_hash: string;
+  executable_hash: string;
+  repo_url: string;
+  commit: string;
+  last_verified_at: string | null;
+  is_frozen: boolean;
+  is_closed: boolean;
+};
+
+/** Returns verified build info from the OtterSec registry, or null if unverified or the request fails. */
+export async function verifiedBuild(
+  programId: PublicKey,
+): Promise<VerifiedBuild | null> {
+  try {
+    const resp = await fetch(
+      `${OSEC_REGISTRY_URL}/status/${programId.toString()}`,
+    );
+    if (!resp.ok) return null;
+    const build = (await resp.json()) as VerifiedBuild;
+    return build.is_verified ? build : null;
+  } catch {
+    return null;
+  }
+}
+
 /**
  * Returns the program data account for this program, containing the
  * metadata for this program, e.g., the upgrade authority.
  */
 export async function fetchData(
   connection: Connection,
-  programId: PublicKey
+  programId: PublicKey,
 ): Promise<ProgramData> {
   const accountInfo = await connection.getAccountInfo(programId);
   if (accountInfo === null) {
@@ -16,13 +47,13 @@ export async function fetchData(
   }
   const { program } = decodeUpgradeableLoaderState(accountInfo.data);
   const programdataAccountInfo = await connection.getAccountInfo(
-    program.programdataAddress
+    program.programdataAddress,
   );
   if (programdataAccountInfo === null) {
     throw new Error("program data account not found");
   }
   const { programData } = decodeUpgradeableLoaderState(
-    programdataAccountInfo.data
+    programdataAccountInfo.data,
   );
   return programData;
 }
@@ -32,7 +63,7 @@ const UPGRADEABLE_LOADER_STATE_LAYOUT = borsh.rustEnum(
     borsh.struct([], "uninitialized"),
     borsh.struct(
       [borsh.option(borsh.publicKey(), "authorityAddress")],
-      "buffer"
+      "buffer",
     ),
     borsh.struct([borsh.publicKey("programdataAddress")], "program"),
     borsh.struct(
@@ -40,11 +71,11 @@ const UPGRADEABLE_LOADER_STATE_LAYOUT = borsh.rustEnum(
         borsh.u64("slot"),
         borsh.option(borsh.publicKey(), "upgradeAuthorityAddress"),
       ],
-      "programData"
+      "programData",
     ),
   ],
   undefined,
-  borsh.u32()
+  borsh.u32(),
 );
 
 export function decodeUpgradeableLoaderState(data: Buffer): any {