diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c8155383..811a93d7c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ All notable changes to OriginWeave are documented in this file. The format follo
 - Same-call browser-protocol dispatch gating that validates current protocol family, adapter version, pinned protocol/browser revisions, OriginWeave generation, and required capability before invoking one callback, transferring the non-cloneable validation proof by ownership without turning metadata validation into browser or Agent authority.
 - Context-bound browser-protocol dispatch composition that revalidates the exact OriginWeave browser session/context pair, carries the registry's current document epoch into the immediate callback, and separately requires the same exact runtime protocol metadata/capability checks before dispatch without claiming origin, destination, typed-input, transport-authentication, or post-condition authority.
 - Explicit `BrowserAuthorityRegistry::bind_context_origin` registration that binds one canonical origin to the exact current browser session, browsing context, and document epoch before origin-sensitive protocol use, rejecting cross-session ownership and same-epoch origin changes without granting navigation or action authority.
+- Explicit `BrowserAuthorityRegistry::require_context_origin` revalidation that requires the exact registered canonical origin for the current browser session, browsing context, and document epoch before origin-sensitive protocol use, failing closed when binding is absent or mismatched without granting navigation or action authority.
 - Credential-safe browser-protocol validation evidence that copies only the already validated protocol family, OriginWeave generation, adapter version, pinned protocol/browser revisions, and exact capability into cloneable audit metadata without recreating the non-cloneable validation prerequisite or granting browser/Agent authority.
 - Canonical HTTPS and loopback-origin boundary with case-normalized schemes and hosts, default-port normalization, IPv4/IPv6 handling, browser-special numeric-host rejection, and explicit malformed-input errors.
 - Typed browser actions, capabilities, risk classes, execution modes, robots decisions, secret-delivery contracts, immutable canonical action-intent digests, and intent-bound approval scopes.
diff --git a/crates/originweave-core/src/browser_registry.rs b/crates/originweave-core/src/browser_registry.rs
index 4ec84522b..477117e4e 100644
--- a/crates/originweave-core/src/browser_registry.rs
+++ b/crates/originweave-core/src/browser_registry.rs
@@ -227,6 +227,34 @@ impl BrowserAuthorityRegistry {
         Ok(epoch)
     }
 
+    /// Revalidate the canonical origin bound to the exact current browser document.
+    ///
+    /// This read-only immediate-use boundary lets a trusted browser adapter prove that the exact
+    /// OriginWeave session/context still has the expected canonical origin in its current document
+    /// epoch. It fails closed when the current document has no origin binding, including directly
+    /// after [`Self::advance_document`], and rejects a different origin without mutating registry
+    /// state. The returned epoch is descriptive current state, not a reusable capability.
+    ///
+    /// This method does not authenticate the adapter or browser process, derive the current origin
+    /// from Chromium, authorize a destination or action, perform browser I/O, or attest that the
+    /// caller-supplied origin came from the running browser.
+    pub fn require_context_origin(
+        &self,
+        browser_session: BrowserSessionId,
+        browsing_context: BrowsingContextId,
+        origin: &Origin,
+    ) -> Result<DocumentEpoch, BrowserRegistryError> {
+        let epoch = self.current_context_epoch(browser_session, browsing_context)?;
+        let expected_origin = self
+            .context_origin
+            .get(&browsing_context)
+            .ok_or(BrowserRegistryError::ContextOriginNotBound)?;
+        if expected_origin != origin {
+            return Err(BrowserRegistryError::OriginChangedWithoutDocumentAdvance);
+        }
+        Ok(epoch)
+    }
+
     /// Advance a browsing context to the next document epoch and invalidate old node bindings.
     ///
     /// Call this whenever navigation or document replacement invalidates actionable node identity.
@@ -323,6 +351,8 @@ pub enum BrowserRegistryError {
         /// Session supplied by the current caller.
         actual: BrowserSessionId,
     },
+    /// The current document has no canonical origin bound to the browsing context.
+    ContextOriginNotBound,
     /// The context origin changed without first rotating the document epoch.
     OriginChangedWithoutDocumentAdvance,
     /// The registry exhausted one of its monotonic internal identifier spaces.
@@ -351,6 +381,9 @@ impl fmt::Display for BrowserRegistryError {
                 expected.value(),
                 actual.value()
             ),
+            Self::ContextOriginNotBound => formatter.write_str(
+                "browsing context has no canonical origin bound for the current document",
+            ),
             Self::OriginChangedWithoutDocumentAdvance => formatter
                 .write_str("browsing context origin changed without advancing the document epoch"),
             Self::IdentifierSpaceExhausted => {
@@ -640,6 +673,7 @@ mod tests {
                 expected: expected_values[0],
                 actual: actual_values[0],
             },
+            BrowserRegistryError::ContextOriginNotBound,
             BrowserRegistryError::OriginChangedWithoutDocumentAdvance,
             BrowserRegistryError::IdentifierSpaceExhausted,
             BrowserRegistryError::DocumentEpochExhausted,
diff --git a/crates/originweave-core/tests/browser_context_origin_revalidation.rs b/crates/originweave-core/tests/browser_context_origin_revalidation.rs
new file mode 100644
index 000000000..7f35fab1d
--- /dev/null
+++ b/crates/originweave-core/tests/browser_context_origin_revalidation.rs
@@ -0,0 +1,97 @@
+use std::error::Error;
+use std::io;
+
+use originweave_core::{BrowserAuthorityRegistry, BrowserRegistryError, Origin};
+
+fn first_origin() -> Result<Origin, io::Error> {
+    Origin::parse("http://127.0.0.1:43127")
+        .map_err(|_error| io::Error::other("controlled first origin must be valid"))
+}
+
+fn second_origin() -> Result<Origin, io::Error> {
+    Origin::parse("http://localhost:43127")
+        .map_err(|_error| io::Error::other("controlled second origin must be valid"))
+}
+
+#[test]
+fn current_context_origin_must_be_bound_before_revalidation() -> Result<(), Box<dyn Error>> {
+    let mut registry = BrowserAuthorityRegistry::new();
+    let session = registry.register_session("webdriver-session")?;
+    let context = registry.register_context(session, "top-level-context")?;
+    let origin = first_origin()?;
+
+    assert_eq!(
+        registry.require_context_origin(session, context, &origin),
+        Err(BrowserRegistryError::ContextOriginNotBound)
+    );
+
+    let epoch = registry.bind_context_origin(session, context, &origin)?;
+    assert_eq!(
+        registry.require_context_origin(session, context, &origin),
+        Ok(epoch)
+    );
+    Ok(())
+}
+
+#[test]
+fn current_context_origin_revalidation_fails_closed_on_mismatch() -> Result<(), Box<dyn Error>> {
+    let mut registry = BrowserAuthorityRegistry::new();
+    let session = registry.register_session("webdriver-session")?;
+    let context = registry.register_context(session, "top-level-context")?;
+    let first = first_origin()?;
+    let second = second_origin()?;
+
+    registry.bind_context_origin(session, context, &first)?;
+    assert_eq!(
+        registry.require_context_origin(session, context, &second),
+        Err(BrowserRegistryError::OriginChangedWithoutDocumentAdvance)
+    );
+    assert!(
+        registry
+            .require_context_origin(session, context, &first)
+            .is_ok()
+    );
+    Ok(())
+}
+
+#[test]
+fn document_rotation_requires_fresh_origin_binding() -> Result<(), Box<dyn Error>> {
+    let mut registry = BrowserAuthorityRegistry::new();
+    let session = registry.register_session("webdriver-session")?;
+    let context = registry.register_context(session, "top-level-context")?;
+    let first = first_origin()?;
+    let second = second_origin()?;
+
+    registry.bind_context_origin(session, context, &first)?;
+    let next_epoch = registry.advance_document(context)?;
+    assert_eq!(
+        registry.require_context_origin(session, context, &first),
+        Err(BrowserRegistryError::ContextOriginNotBound)
+    );
+
+    registry.bind_context_origin(session, context, &second)?;
+    assert_eq!(
+        registry.require_context_origin(session, context, &second),
+        Ok(next_epoch)
+    );
+    Ok(())
+}
+
+#[test]
+fn context_origin_revalidation_preserves_session_ownership() -> Result<(), Box<dyn Error>> {
+    let mut registry = BrowserAuthorityRegistry::new();
+    let owner = registry.register_session("owner-session")?;
+    let attacker = registry.register_session("attacker-session")?;
+    let context = registry.register_context(owner, "top-level-context")?;
+    let origin = first_origin()?;
+
+    registry.bind_context_origin(owner, context, &origin)?;
+    assert_eq!(
+        registry.require_context_origin(attacker, context, &origin),
+        Err(BrowserRegistryError::ContextSessionMismatch {
+            expected: owner,
+            actual: attacker,
+        })
+    );
+    Ok(())
+}
diff --git a/tests/test_repository_contract.py b/tests/test_repository_contract.py
index 07ddea2d5..34a92da9c 100644
--- a/tests/test_repository_contract.py
+++ b/tests/test_repository_contract.py
@@ -181,6 +181,12 @@ def test_context_origin_binding_is_recorded_in_the_changelog(self) -> None:
         changelog = (ROOT / "CHANGELOG.md").read_text(encoding="utf-8")
         self.assertIn("BrowserAuthorityRegistry::bind_context_origin", changelog)
 
+    def test_context_origin_revalidation_is_recorded_in_the_changelog(self) -> None:
+        """The public origin-revalidation boundary must remain visible in release history."""
+
+        changelog = (ROOT / "CHANGELOG.md").read_text(encoding="utf-8")
+        self.assertIn("BrowserAuthorityRegistry::require_context_origin", changelog)
+
     def test_database_contract_requires_two_word_snake_case(self) -> None:
         """Persistent naming policy must include the mandated canonical form."""