diff --git a/capiscio_mcp/connect.py b/capiscio_mcp/connect.py
index a8648f4..2423944 100644
--- a/capiscio_mcp/connect.py
+++ b/capiscio_mcp/connect.py
@@ -144,6 +144,21 @@ def _derive_domain(url: str) -> str:
     return host
 
 
+def _derive_did_web(server_url: str, server_id: str) -> str:
+    """Derive the did:web identity for a registered server.
+
+    Matches the Go CA's did.NewAgentDID(domain, agentID) output:
+        did:web:<domain>:agents:<uuid>
+
+    In CA-connected mode the badge subject is always a did:web — the server
+    must present the same DID for identity verification to pass.
+    """
+    domain = _derive_domain(server_url)
+    # did:web spec encodes colons in the domain as %3A
+    encoded_domain = domain.replace(":", "%3A")
+    return f"did:web:{encoded_domain}:agents:{server_id}"
+
+
 def _issue_badge_sync(
     server_id: str,
     api_key: str,
@@ -516,6 +531,18 @@ async def connect(
         if is_new_identity:
             _log_key_capture_hint(server_id, private_key_pem)
 
+        # ------------------------------------------------------------------
+        # Step 4: Derive did:web identity (CA-connected mode)
+        # ------------------------------------------------------------------
+        # The CA issues badges with sub = did:web:{domain}:agents:{uuid}.
+        # For identity verification to pass, the server must present the same
+        # did:web — NOT the did:key from key generation.  The keypair is still
+        # used for PoP signing, but the identity DID is always did:web when
+        # connected to a CA.
+        did = _derive_did_web(server_url, server_id)
+        did_file.write_text(did)
+        logger.info("Server identity DID (CA-connected): %s", did)
+
         # Update bundle URL if registration yielded a new/different org_id.
         # (API key and cached bundle URL were already set in Step 1.5 before
         # the Go core could be started.)
diff --git a/capiscio_mcp/integrations/mcp.py b/capiscio_mcp/integrations/mcp.py
index c1bc5b1..643fab0 100644
--- a/capiscio_mcp/integrations/mcp.py
+++ b/capiscio_mcp/integrations/mcp.py
@@ -682,9 +682,19 @@ def __init__(
         self.min_trust_level = min_trust_level
         self.fail_on_unverified = fail_on_unverified
         self.require_pop = require_pop
-        self.verify_config = verify_config or VerifyConfig(min_trust_level=min_trust_level)
         self._extra_env = env or {}
 
+        # For stdio transports (subprocess-based), origin binding is not
+        # applicable — there is no HTTP origin to bind against.  Auto-skip
+        # the check unless the caller provided an explicit verify_config.
+        if verify_config is not None:
+            self.verify_config = verify_config
+        else:
+            self.verify_config = VerifyConfig(
+                min_trust_level=min_trust_level,
+                skip_origin_binding=(command is not None),
+            )
+
         self._credential = CallerCredential(
             badge_jws=badge,
             api_key=api_key,
diff --git a/capiscio_mcp/server.py b/capiscio_mcp/server.py
index 608503f..3063519 100644
--- a/capiscio_mcp/server.py
+++ b/capiscio_mcp/server.py
@@ -155,7 +155,16 @@ async def verify_server(
     
     # Full verification path: DID + badge requires gRPC validation
     # Get core client
-    client = await CoreClient.get_instance()
+    try:
+        client = await CoreClient.get_instance()
+    except Exception as exc:
+        logger.warning("Cannot reach capiscio-core for server verification: %s", exc)
+        return VerifyResult(
+            state=ServerState.UNVERIFIED_ORIGIN,
+            server_did=server_did,
+            error_code=ServerErrorCode.BADGE_INVALID,
+            error_detail=f"capiscio-core unavailable: {exc}",
+        )
     
     # Import proto
     from capiscio_mcp._proto.capiscio.v1 import mcp_pb2
@@ -176,7 +185,16 @@ async def verify_server(
     )
     
     # Make RPC call
-    response = await client.stub.VerifyServerIdentity(request)
+    try:
+        response = await client.stub.VerifyServerIdentity(request)
+    except Exception as exc:
+        logger.warning("gRPC call to VerifyServerIdentity failed: %s", exc)
+        return VerifyResult(
+            state=ServerState.UNVERIFIED_ORIGIN,
+            server_did=server_did,
+            error_code=ServerErrorCode.BADGE_INVALID,
+            error_detail=f"verification RPC failed: {exc}",
+        )
     
     # Map response state
     state_map = {