diff --git a/Cargo.lock b/Cargo.lock
index 62b68b34..e856c29b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5031,6 +5031,20 @@ dependencies = [
  "rayon",
 ]
 
+[[package]]
+name = "provekit-verifier"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1ff1bcdce6c807b04657898aae2fd863bd4958b7ded64aaad4f10156061d7b6"
+dependencies = [
+ "anyhow",
+ "ark-std 0.5.0",
+ "provekit-common",
+ "provekit-whir",
+ "rayon",
+ "tracing",
+]
+
 [[package]]
 name = "provekit-whir"
 version = "0.1.1"
@@ -8176,6 +8190,7 @@ version = "0.17.1"
 dependencies = [
  "alloy",
  "base64 0.22.1",
+ "ciborium",
  "clap",
  "dirs",
  "eyre",
@@ -8190,6 +8205,7 @@ dependencies = [
  "tracing-subscriber 0.3.23",
  "walletkit-core",
  "world-id-core",
+ "world-id-proof",
 ]
 
 [[package]]
@@ -9067,6 +9083,7 @@ dependencies = [
  "eyre",
  "provekit-common",
  "provekit-prover",
+ "provekit-verifier",
  "rand 0.8.6",
  "rayon",
  "reqwest 0.12.28",
diff --git a/Cargo.toml b/Cargo.toml
index 61874cd3..9b3a151f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,3 +56,17 @@ opt-level = 'z' # Optimize for size.
 lto = true      # Enable Link Time Optimization.
 panic = "abort"
 debug = false
+
+# ProveKit has an additional `pattern` in the Whir R1CS proof which is used in debugging builds,
+# because this isn't serialized, we explicitly remove it here as WalletKit only uses serialized proofs.
+[profile.dev.package.provekit-common]
+debug-assertions = false
+
+[profile.dev.package.provekit-whir]
+debug-assertions = false
+
+[profile.dev.package.provekit-verifier]
+debug-assertions = false
+
+[profile.dev.package.provekit-prover]
+debug-assertions = false
diff --git a/walletkit-cli/Cargo.toml b/walletkit-cli/Cargo.toml
index f0b314cf..325a2b3f 100644
--- a/walletkit-cli/Cargo.toml
+++ b/walletkit-cli/Cargo.toml
@@ -15,8 +15,10 @@ path = "src/main.rs"
 [dependencies]
 walletkit-core = { workspace = true, features = ["issuers", "embed-zkeys"] }
 world-id-core = { workspace = true }
+world-id-proof = { workspace = true, features = ["zk-ownership-verify"] }
 alloy = { version = "2", default-features = false, features = ["contract", "json", "getrandom", "signer-local"] }
 base64 = "0.22"
+ciborium = "0.2"
 clap = { version = "4", features = ["derive", "env"] }
 dirs = "6"
 eyre = "0.6"
diff --git a/walletkit-cli/src/commands/proof.rs b/walletkit-cli/src/commands/proof.rs
index 13759d20..58c67a45 100644
--- a/walletkit-cli/src/commands/proof.rs
+++ b/walletkit-cli/src/commands/proof.rs
@@ -6,15 +6,17 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use alloy::providers::ProviderBuilder;
 use alloy::signers::{local::PrivateKeySigner, SignerSync};
 use alloy::sol;
+use base64::{prelude::BASE64_URL_SAFE_NO_PAD, Engine as _};
 use clap::Subcommand;
 use eyre::WrapErr as _;
 use rand::rngs::OsRng;
 use walletkit_core::requests::ProofRequest;
-use world_id_core::primitives::{rp::RpId, FieldElement};
+use world_id_core::primitives::{rp::RpId, FieldElement, OwnershipProof};
 use world_id_core::requests::{
     ProofRequest as CoreProofRequest, ProofResponse as CoreProofResponse, RequestItem,
     RequestVersion,
 };
+use world_id_proof::ownership_proof::verify_ownership_proof;
 
 use crate::output;
 
@@ -93,6 +95,18 @@ pub enum ProofCommand {
         #[arg(long, default_value = "test_signal")]
         signal: String,
     },
+    /// Verify a WIP-103 ownership proof from a base64-encoded file.
+    VerifyOwnership {
+        /// Path to a file containing the base64url-encoded ownership proof, or `-` for stdin.
+        #[arg(long)]
+        proof: String,
+        /// Nonce used when generating the proof, as a 32-byte hex field element (with optional `0x` prefix).
+        #[arg(long)]
+        nonce: String,
+        /// Credential `sub` (commitment) the proof claims ownership of, as a 32-byte hex field element.
+        #[arg(long)]
+        sub: String,
+    },
 }
 
 fn read_file_or_stdin(path: &str) -> eyre::Result<String> {
@@ -248,12 +262,15 @@ fn print_verify_items_human(results: &[VerifyItemResult]) {
     for r in results {
         if r.verified {
             println!(
-                "  [PASS] {} (issuer_schema_id={})",
-                r.identifier, r.issuer_schema_id
+                "  {} {} (issuer_schema_id={})",
+                output::pass_label(),
+                r.identifier,
+                r.issuer_schema_id
             );
         } else {
             println!(
-                "  [FAIL] {} (issuer_schema_id={}): {}",
+                "  {} {} (issuer_schema_id={}): {}",
+                output::fail_label(),
                 r.identifier,
                 r.issuer_schema_id,
                 r.error.as_deref().unwrap_or("unknown")
@@ -459,6 +476,57 @@ async fn run_test(cli: &Cli, signal: &str) -> eyre::Result<()> {
     Ok(())
 }
 
+fn parse_field_element(value: &str, label: &str) -> eyre::Result<FieldElement> {
+    value.trim().parse::<FieldElement>().wrap_err_with(|| {
+        format!("invalid {label}: expected 32-byte hex field element")
+    })
+}
+
+fn run_verify_ownership(
+    cli: &Cli,
+    proof_path: &str,
+    nonce: &str,
+    sub: &str,
+) -> eyre::Result<()> {
+    let b64 = read_file_or_stdin(proof_path)?;
+    let bytes = BASE64_URL_SAFE_NO_PAD
+        .decode(b64.trim())
+        .wrap_err("invalid base64 ownership proof")?;
+    let proof: OwnershipProof = ciborium::from_reader(&bytes[..])
+        .wrap_err("failed to decode ownership proof CBOR")?;
+
+    let nonce_fe = parse_field_element(nonce, "--nonce")?;
+    let sub_fe = parse_field_element(sub, "--sub")?;
+
+    let result = verify_ownership_proof(&proof, nonce_fe, sub_fe);
+    let merkle_root = proof.merkle_root.to_string();
+
+    if cli.json {
+        output::print_json_data(
+            &serde_json::json!({
+                "verified": result.is_ok(),
+                "merkle_root": merkle_root,
+                "error": result.as_ref().err().map(|e| format!("{e:#}")),
+            }),
+            true,
+        );
+    } else if let Err(ref err) = result {
+        println!(
+            "{} ownership proof verification failed: {err:#}",
+            output::fail_label()
+        );
+        println!("  merkle_root: {merkle_root}");
+    } else {
+        println!("{} ownership proof verified", output::pass_label());
+        println!("  merkle_root: {merkle_root}");
+    }
+
+    if result.is_err() {
+        std::process::exit(1);
+    }
+    Ok(())
+}
+
 pub async fn run(cli: &Cli, action: &ProofCommand) -> eyre::Result<()> {
     match action {
         ProofCommand::Generate { request, now } => {
@@ -476,5 +544,8 @@ pub async fn run(cli: &Cli, action: &ProofCommand) -> eyre::Result<()> {
             verifier_address,
         } => run_verify(cli, request, response, verifier_address.as_deref()).await,
         ProofCommand::Test { signal } => run_test(cli, signal).await,
+        ProofCommand::VerifyOwnership { proof, nonce, sub } => {
+            run_verify_ownership(cli, proof, nonce, sub)
+        }
     }
 }
diff --git a/walletkit-cli/src/output.rs b/walletkit-cli/src/output.rs
index d558be20..086db4cf 100644
--- a/walletkit-cli/src/output.rs
+++ b/walletkit-cli/src/output.rs
@@ -1,5 +1,31 @@
 //! Output formatting helpers for human-readable and JSON modes.
 
+use std::io::IsTerminal as _;
+
+const GREEN: &str = "\x1b[32m";
+const RED: &str = "\x1b[31m";
+const RESET: &str = "\x1b[0m";
+
+fn colorize(label: &str, color: &str) -> String {
+    if std::io::stdout().is_terminal() {
+        format!("{color}{label}{RESET}")
+    } else {
+        label.to_string()
+    }
+}
+
+/// Returns `[PASS]` colored green when stdout is a TTY, otherwise plain.
+#[must_use]
+pub fn pass_label() -> String {
+    colorize("[PASS]", GREEN)
+}
+
+/// Returns `[FAIL]` colored red when stdout is a TTY, otherwise plain.
+#[must_use]
+pub fn fail_label() -> String {
+    colorize("[FAIL]", RED)
+}
+
 /// Prints a raw JSON value wrapped in the standard envelope.
 pub fn print_json_data(data: &serde_json::Value, json: bool) {
     if json {