diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7f369c4a..4b5c60f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,10 @@ and this project adheres to
 
 # Unreleased
 
+- runtime: treat a blank `CA_CERTIFICATE` / `DISABLE_TLS_VERIFICATION` as unset
+  when the integration did not declare the field, so an empty value written by
+  the platform cannot abort the run
+
 # 17.6.0 - 2026-08-18
 
 - runtime: always expose `caCertificate` and `disableTlsVerification` from the
diff --git a/packages/integration-sdk-runtime/src/execution/__tests__/config.test.ts b/packages/integration-sdk-runtime/src/execution/__tests__/config.test.ts
index ce914ca7..0327c423 100644
--- a/packages/integration-sdk-runtime/src/execution/__tests__/config.test.ts
+++ b/packages/integration-sdk-runtime/src/execution/__tests__/config.test.ts
@@ -155,6 +155,65 @@ test('respects integration-declared caCertificate / disableTlsVerification over
   expect(config).toEqual({ caCertificate: 'cert-value' });
 });
 
+test('a declared caCertificate replaces the implicit one, so it is no longer optional', () => {
+  // The implicit definition is optional, so an unset CA_CERTIFICATE would
+  // resolve to undefined. Declaring the field without `optional` has to win,
+  // which is only observable when the environment variable is missing.
+  const instanceConfigFields: IntegrationInstanceConfigFieldMap<
+    Record<'caCertificate', IntegrationInstanceConfigField>
+  > = {
+    caCertificate: {
+      type: 'string',
+    },
+  };
+
+  expect(() =>
+    loadConfigFromEnvironmentVariables(instanceConfigFields),
+  ).toThrow(
+    'Expected environment variable "CA_CERTIFICATE" for config field "caCertificate" to be set.',
+  );
+});
+
+test('treats a blank implicit agent-configuration variable as unset', () => {
+  // The platform writes these for every integration, none of which declared
+  // them. A blank value must not fail the boolean conversion and abort the run.
+  process.env.CA_CERTIFICATE = '';
+  process.env.DISABLE_TLS_VERIFICATION = '';
+
+  const config = loadConfigFromEnvironmentVariables({});
+
+  expect(config).toEqual({});
+});
+
+test('treats a whitespace-only implicit agent-configuration variable as unset', () => {
+  process.env.CA_CERTIFICATE = '  ';
+  process.env.DISABLE_TLS_VERIFICATION = ' ';
+
+  const config = loadConfigFromEnvironmentVariables({});
+
+  expect(config).toEqual({});
+});
+
+test('still rejects a blank value for an agent-configuration field the integration declared', () => {
+  // Once the integration declares the field it owns it, and a value the
+  // integration cannot parse stays an error rather than being ignored.
+  process.env.DISABLE_TLS_VERIFICATION = '';
+  const instanceConfigFields: IntegrationInstanceConfigFieldMap<
+    Record<'disableTlsVerification', IntegrationInstanceConfigField>
+  > = {
+    disableTlsVerification: {
+      type: 'boolean',
+      optional: true,
+    },
+  };
+
+  expect(() =>
+    loadConfigFromEnvironmentVariables(instanceConfigFields),
+  ).toThrow(
+    'Expected boolean value for field "disableTlsVerification" but received "".',
+  );
+});
+
 test('loads environment variables from .env', () => {
   vol.fromJSON({
     [path.join(process.cwd(), '.env')]: 'MY_ENV_VAR=mochi',
diff --git a/packages/integration-sdk-runtime/src/execution/config.ts b/packages/integration-sdk-runtime/src/execution/config.ts
index 6636e16b..c7800393 100644
--- a/packages/integration-sdk-runtime/src/execution/config.ts
+++ b/packages/integration-sdk-runtime/src/execution/config.ts
@@ -48,7 +48,19 @@ export function loadConfigFromEnvironmentVariables<
 
       const environmentVariableValue = process.env[environmentVariableName];
 
-      if (environmentVariableValue === undefined) {
+      // An implicit field is present only because the platform may have written
+      // it into the environment; the integration never asked for it. A blank
+      // value there means "not configured", not "malformed" — without this, a
+      // stray `DISABLE_TLS_VERIFICATION=` would fail the boolean conversion and
+      // abort the run of every integration rather than only the ones that
+      // declared the field.
+      const isUndeclaredImplicitField =
+        field in IMPLICIT_AGENT_CONFIG_FIELDS && !(field in configMap);
+
+      if (
+        environmentVariableValue === undefined ||
+        (isUndeclaredImplicitField && environmentVariableValue.trim() === '')
+      ) {
         if (config.optional) {
           return [field, undefined];
         } else {