diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98ea474..7995e69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,35 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [6.1.0] - 2026-04-25 — Plugin Batch 1 / ADR-043 explainability fields on MCP responses
+
+Minor release. Surfaces fields the AxonFlow agent has emitted since v7.1.0 (Plugin Batch 1 / ADR-042 / ADR-043) but the SDK didn't declare. Pure Cat B field-additions on existing methods — additive only, no breaking changes. The pre-existing constructors are preserved as source-compat overloads. Documented in OpenAPI via platform v7.4.3 (axonflow-enterprise#1714); SDK catches up here.
+
+Coordinated cycle: TypeScript v6.1.0 / Python v6.8.0 / Go v5.8.0 ship same day with the same field set.
+
+### Added
+
+- **`MCPCheckInputResponse`** gains 5 optional Plugin Batch 1 fields:
+  - `decisionId: String` — audit correlator
+  - `riskLevel: String` — `low` | `medium` | `high` | `critical`
+  - `policyMatches: List<ExplainPolicy>` — per-policy explainability records
+  - `overrideAvailable: Boolean` — whether session override is permitted for the matched policies (boxed so callers can distinguish "unset" from `false` on older platforms)
+  - `overrideExistingId: String` — already-active override consumed by this decision (if any)
+- **`MCPCheckOutputResponse`** gains 3 optional fields:
+  - `decisionId: String`
+  - `policyMatches: List<ExplainPolicy>`
+  - `redactedMessage: String` — text-redaction counterpart to `redactedData` (used when the connector returned a string message rather than tabular rows; e.g. execute-style responses)
+
+`ExplainPolicy` already shipped — same Jackson-annotated record now reused on the MCP response types. Pre-v7.1.0 platforms leave all new fields as `null`; callers should treat `null` as "context not available" rather than an error.
+
+### Source compatibility
+
+Both `MCPCheckInputResponse` and `MCPCheckOutputResponse` retain their v6.0.0 constructor signatures as overloads that delegate to the new `@JsonCreator` constructors with `null` for the new fields. Existing callers that build response instances locally compile unchanged. `equals()` / `hashCode()` / `toString()` updated to include the new fields.
+
+### Deferred
+
+`client.explainDecision(decisionId)` and the full `ExplainRule` / `DecisionExplanation` type surface are tracked separately as feature work — see axonflow-enterprise#1716. This release ships only field-surfacing on existing methods.
+
 ## [6.0.0] - 2026-04-25 — Major: WebhookSubscription identity-based equality
 
 This is a major release. The bump is driven by a single observable-contract change: `WebhookSubscription.equals()` and `.hashCode()` now compare on `id` only, not every field. Coordinated with the TypeScript SDK v6.0.0 release (PolicyInfo rename) as a v6 alignment cycle for the SDKs that needed breaking changes; Python (v6.7.0) and Go (v5.7.0) ship as minor on the same day because their changes are purely additive.
diff --git a/pom.xml b/pom.xml
index c26fa07..620c40d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>com.getaxonflow</groupId>
     <artifactId>axonflow-sdk</artifactId>
-    <version>6.0.0</version>
+    <version>6.1.0</version>
     <packaging>jar</packaging>
 
     <name>AxonFlow Java SDK</name>
diff --git a/src/main/java/com/getaxonflow/sdk/types/MCPCheckInputResponse.java b/src/main/java/com/getaxonflow/sdk/types/MCPCheckInputResponse.java
index ee50c5c..281e0c8 100644
--- a/src/main/java/com/getaxonflow/sdk/types/MCPCheckInputResponse.java
+++ b/src/main/java/com/getaxonflow/sdk/types/MCPCheckInputResponse.java
@@ -18,6 +18,7 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.List;
 import java.util.Objects;
 
 /**
@@ -26,6 +27,11 @@
  * <p>Indicates whether the input statement is allowed by configured policies. A 403 HTTP response
  * still returns a valid response body with {@code allowed=false} and details in {@code blockReason}
  * and {@code policyInfo}.
+ *
+ * <p>The five Plugin Batch 1 / ADR-042 / ADR-043 fields ({@code decisionId}, {@code riskLevel},
+ * {@code policyMatches}, {@code overrideAvailable}, {@code overrideExistingId}) are populated
+ * when the AxonFlow platform is v7.1.0+. Pre-v7.1.0 platforms leave these as {@code null}.
+ * Source of truth: {@code platform/agent/mcp_server_handler.go:880-940}.
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
 public final class MCPCheckInputResponse {
@@ -42,16 +48,52 @@ public final class MCPCheckInputResponse {
   @JsonProperty("policy_info")
   private final ConnectorPolicyInfo policyInfo;
 
+  @JsonProperty("decision_id")
+  private final String decisionId;
+
+  @JsonProperty("risk_level")
+  private final String riskLevel;
+
+  @JsonProperty("policy_matches")
+  private final List<ExplainPolicy> policyMatches;
+
+  @JsonProperty("override_available")
+  private final Boolean overrideAvailable;
+
+  @JsonProperty("override_existing_id")
+  private final String overrideExistingId;
+
   @JsonCreator
   public MCPCheckInputResponse(
       @JsonProperty("allowed") boolean allowed,
       @JsonProperty("block_reason") String blockReason,
       @JsonProperty("policies_evaluated") int policiesEvaluated,
-      @JsonProperty("policy_info") ConnectorPolicyInfo policyInfo) {
+      @JsonProperty("policy_info") ConnectorPolicyInfo policyInfo,
+      @JsonProperty("decision_id") String decisionId,
+      @JsonProperty("risk_level") String riskLevel,
+      @JsonProperty("policy_matches") List<ExplainPolicy> policyMatches,
+      @JsonProperty("override_available") Boolean overrideAvailable,
+      @JsonProperty("override_existing_id") String overrideExistingId) {
     this.allowed = allowed;
     this.blockReason = blockReason;
     this.policiesEvaluated = policiesEvaluated;
     this.policyInfo = policyInfo;
+    this.decisionId = decisionId;
+    this.riskLevel = riskLevel;
+    this.policyMatches = policyMatches;
+    this.overrideAvailable = overrideAvailable;
+    this.overrideExistingId = overrideExistingId;
+  }
+
+  /**
+   * Source-compat overload. Callers that build {@code MCPCheckInputResponse} instances locally
+   * with the v6.0.0 4-argument shape continue to compile — the five Plugin Batch 1 fields default
+   * to {@code null}. Server-side responses always go through the {@code @JsonCreator} 9-arg
+   * constructor regardless.
+   */
+  public MCPCheckInputResponse(
+      boolean allowed, String blockReason, int policiesEvaluated, ConnectorPolicyInfo policyInfo) {
+    this(allowed, blockReason, policiesEvaluated, policyInfo, null, null, null, null, null);
   }
 
   /** Returns whether the input is allowed by policies. */
@@ -74,6 +116,46 @@ public ConnectorPolicyInfo getPolicyInfo() {
     return policyInfo;
   }
 
+  /**
+   * Returns the audit correlator for this policy decision (Plugin Batch 1, v7.1.0+). Null on
+   * older platforms.
+   */
+  public String getDecisionId() {
+    return decisionId;
+  }
+
+  /**
+   * Returns the highest risk level across matched policies ({@code low} | {@code medium} |
+   * {@code high} | {@code critical}; Plugin Batch 1, v7.1.0+). Null on older platforms.
+   */
+  public String getRiskLevel() {
+    return riskLevel;
+  }
+
+  /**
+   * Returns the per-policy explainability records (ADR-043, v7.1.0+). Null on older platforms.
+   */
+  public List<ExplainPolicy> getPolicyMatches() {
+    return policyMatches;
+  }
+
+  /**
+   * Returns whether at least one matched policy permits a session override (Plugin Batch 1,
+   * v7.1.0+). Null on older platforms; callers should treat null as "context not available"
+   * rather than {@code false}.
+   */
+  public Boolean getOverrideAvailable() {
+    return overrideAvailable;
+  }
+
+  /**
+   * Returns the ID of an active override consumed by this decision, if any (Plugin Batch 1,
+   * v7.1.0+). Null on older platforms or when no override was consumed.
+   */
+  public String getOverrideExistingId() {
+    return overrideExistingId;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
@@ -82,12 +164,26 @@ public boolean equals(Object o) {
     return allowed == that.allowed
         && policiesEvaluated == that.policiesEvaluated
         && Objects.equals(blockReason, that.blockReason)
-        && Objects.equals(policyInfo, that.policyInfo);
+        && Objects.equals(policyInfo, that.policyInfo)
+        && Objects.equals(decisionId, that.decisionId)
+        && Objects.equals(riskLevel, that.riskLevel)
+        && Objects.equals(policyMatches, that.policyMatches)
+        && Objects.equals(overrideAvailable, that.overrideAvailable)
+        && Objects.equals(overrideExistingId, that.overrideExistingId);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(allowed, blockReason, policiesEvaluated, policyInfo);
+    return Objects.hash(
+        allowed,
+        blockReason,
+        policiesEvaluated,
+        policyInfo,
+        decisionId,
+        riskLevel,
+        policyMatches,
+        overrideAvailable,
+        overrideExistingId);
   }
 
   @Override
@@ -102,6 +198,19 @@ public String toString() {
         + policiesEvaluated
         + ", policyInfo="
         + policyInfo
+        + ", decisionId='"
+        + decisionId
+        + '\''
+        + ", riskLevel='"
+        + riskLevel
+        + '\''
+        + ", policyMatches="
+        + policyMatches
+        + ", overrideAvailable="
+        + overrideAvailable
+        + ", overrideExistingId='"
+        + overrideExistingId
+        + '\''
         + '}';
   }
 }
diff --git a/src/main/java/com/getaxonflow/sdk/types/MCPCheckOutputResponse.java b/src/main/java/com/getaxonflow/sdk/types/MCPCheckOutputResponse.java
index 1fa8a4b..933f0b1 100644
--- a/src/main/java/com/getaxonflow/sdk/types/MCPCheckOutputResponse.java
+++ b/src/main/java/com/getaxonflow/sdk/types/MCPCheckOutputResponse.java
@@ -18,14 +18,20 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.List;
 import java.util.Objects;
 
 /**
  * Response from the MCP output policy check endpoint.
  *
- * <p>Indicates whether the output data passes configured policies. May include redacted data if PII
- * redaction policies are active, and exfiltration check information if data volume limits are
- * configured.
+ * <p>Indicates whether the output data passes configured policies. May include redacted data
+ * (tabular) or a redacted message (text) if PII redaction policies are active, and exfiltration
+ * check information if data volume limits are configured.
+ *
+ * <p>The three Plugin Batch 1 / ADR-043 fields ({@code decisionId}, {@code policyMatches},
+ * {@code redactedMessage}) are populated when the AxonFlow platform is v7.1.0+. Pre-v7.1.0
+ * platforms leave these as {@code null}. Source of truth: {@code
+ * platform/agent/mcp_server_handler.go:988, 1005, 1051}.
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
 public final class MCPCheckOutputResponse {
@@ -39,6 +45,9 @@ public final class MCPCheckOutputResponse {
   @JsonProperty("redacted_data")
   private final Object redactedData;
 
+  @JsonProperty("redacted_message")
+  private final String redactedMessage;
+
   @JsonProperty("policies_evaluated")
   private final int policiesEvaluated;
 
@@ -48,20 +57,57 @@ public final class MCPCheckOutputResponse {
   @JsonProperty("policy_info")
   private final ConnectorPolicyInfo policyInfo;
 
+  @JsonProperty("decision_id")
+  private final String decisionId;
+
+  @JsonProperty("policy_matches")
+  private final List<ExplainPolicy> policyMatches;
+
   @JsonCreator
   public MCPCheckOutputResponse(
       @JsonProperty("allowed") boolean allowed,
       @JsonProperty("block_reason") String blockReason,
       @JsonProperty("redacted_data") Object redactedData,
+      @JsonProperty("redacted_message") String redactedMessage,
       @JsonProperty("policies_evaluated") int policiesEvaluated,
       @JsonProperty("exfiltration_info") ExfiltrationCheckInfo exfiltrationInfo,
-      @JsonProperty("policy_info") ConnectorPolicyInfo policyInfo) {
+      @JsonProperty("policy_info") ConnectorPolicyInfo policyInfo,
+      @JsonProperty("decision_id") String decisionId,
+      @JsonProperty("policy_matches") List<ExplainPolicy> policyMatches) {
     this.allowed = allowed;
     this.blockReason = blockReason;
     this.redactedData = redactedData;
+    this.redactedMessage = redactedMessage;
     this.policiesEvaluated = policiesEvaluated;
     this.exfiltrationInfo = exfiltrationInfo;
     this.policyInfo = policyInfo;
+    this.decisionId = decisionId;
+    this.policyMatches = policyMatches;
+  }
+
+  /**
+   * Source-compat overload. Callers that build {@code MCPCheckOutputResponse} instances locally
+   * with the v6.0.0 6-argument shape continue to compile — {@code redactedMessage}, {@code
+   * decisionId}, and {@code policyMatches} default to {@code null}. Server-side responses always
+   * go through the {@code @JsonCreator} 9-arg constructor regardless.
+   */
+  public MCPCheckOutputResponse(
+      boolean allowed,
+      String blockReason,
+      Object redactedData,
+      int policiesEvaluated,
+      ExfiltrationCheckInfo exfiltrationInfo,
+      ConnectorPolicyInfo policyInfo) {
+    this(
+        allowed,
+        blockReason,
+        redactedData,
+        null,
+        policiesEvaluated,
+        exfiltrationInfo,
+        policyInfo,
+        null,
+        null);
   }
 
   /** Returns whether the output data is allowed by policies. */
@@ -74,11 +120,24 @@ public String getBlockReason() {
     return blockReason;
   }
 
-  /** Returns the redacted version of the data, or null if no redaction was applied. */
+  /**
+   * Returns the redacted tabular data with PII fields masked (used when the connector returned
+   * rows; e.g. SQL/CSV results). Null if no redaction was applied or if the response was a text
+   * message.
+   */
   public Object getRedactedData() {
     return redactedData;
   }
 
+  /**
+   * Returns the redacted text message with PII fields masked (used when the connector returned a
+   * string message rather than tabular rows; e.g. execute-style responses). Null if no redaction
+   * was applied or if the response was tabular.
+   */
+  public String getRedactedMessage() {
+    return redactedMessage;
+  }
+
   /** Returns the number of policies evaluated. */
   public int getPoliciesEvaluated() {
     return policiesEvaluated;
@@ -94,6 +153,21 @@ public ConnectorPolicyInfo getPolicyInfo() {
     return policyInfo;
   }
 
+  /**
+   * Returns the audit correlator for this policy decision (Plugin Batch 1, v7.1.0+). Null on
+   * older platforms.
+   */
+  public String getDecisionId() {
+    return decisionId;
+  }
+
+  /**
+   * Returns the per-policy explainability records (ADR-043, v7.1.0+). Null on older platforms.
+   */
+  public List<ExplainPolicy> getPolicyMatches() {
+    return policyMatches;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
@@ -103,14 +177,25 @@ public boolean equals(Object o) {
         && policiesEvaluated == that.policiesEvaluated
         && Objects.equals(blockReason, that.blockReason)
         && Objects.equals(redactedData, that.redactedData)
+        && Objects.equals(redactedMessage, that.redactedMessage)
         && Objects.equals(exfiltrationInfo, that.exfiltrationInfo)
-        && Objects.equals(policyInfo, that.policyInfo);
+        && Objects.equals(policyInfo, that.policyInfo)
+        && Objects.equals(decisionId, that.decisionId)
+        && Objects.equals(policyMatches, that.policyMatches);
   }
 
   @Override
   public int hashCode() {
     return Objects.hash(
-        allowed, blockReason, redactedData, policiesEvaluated, exfiltrationInfo, policyInfo);
+        allowed,
+        blockReason,
+        redactedData,
+        redactedMessage,
+        policiesEvaluated,
+        exfiltrationInfo,
+        policyInfo,
+        decisionId,
+        policyMatches);
   }
 
   @Override
@@ -127,6 +212,11 @@ public String toString() {
         + exfiltrationInfo
         + ", policyInfo="
         + policyInfo
+        + ", decisionId='"
+        + decisionId
+        + '\''
+        + ", policyMatches="
+        + policyMatches
         + '}';
   }
 }
diff --git a/tests/fixtures/wire-shape-baseline.json b/tests/fixtures/wire-shape-baseline.json
index 08d9656..515f3c9 100644
--- a/tests/fixtures/wire-shape-baseline.json
+++ b/tests/fixtures/wire-shape-baseline.json
@@ -182,7 +182,7 @@
       "PolicyMatch": 2
     }
   },
-  "openapi_specs_sha": "10d44eb4585a7b5321d7286b354ff8b43b8c6a57",
+  "openapi_specs_sha": "8c8d6c9c506aa25fcd8a887f6fc71f71b5d6bc30",
   "per_type_drift": {
     "AuditLogEntry": {
       "sdk_only": [
@@ -264,6 +264,20 @@
         "started_at"
       ]
     },
+    "DecisionExplanation": {
+      "sdk_only": [
+        "decisionId",
+        "historicalHitCountSession",
+        "matchedRules",
+        "overrideAvailable",
+        "overrideExistingId",
+        "policyMatches",
+        "policySourceLink",
+        "riskLevel",
+        "toolSignature"
+      ],
+      "spec_only": []
+    },
     "DynamicPolicy": {
       "sdk_only": [
         "category",
@@ -320,6 +334,25 @@
         "limit_type"
       ]
     },
+    "ExplainPolicy": {
+      "sdk_only": [
+        "allowOverride",
+        "policyDescription",
+        "policyId",
+        "policyName",
+        "riskLevel"
+      ],
+      "spec_only": []
+    },
+    "ExplainRule": {
+      "sdk_only": [
+        "matchedOn",
+        "policyId",
+        "ruleId",
+        "ruleText"
+      ],
+      "spec_only": []
+    },
     "ListWorkflowsResponse": {
       "sdk_only": [],
       "spec_only": [
@@ -558,6 +591,7 @@
     "CreateWebhookRequest",
     "CreateWorkflowRequest",
     "CreateWorkflowResponse",
+    "DecisionExplanation",
     "DynamicPolicy",
     "DynamicPolicyInfo",
     "DynamicPolicyMatch",
@@ -565,6 +599,8 @@
     "ExecutionSnapshot",
     "ExecutionSummary",
     "ExfiltrationCheckInfo",
+    "ExplainPolicy",
+    "ExplainRule",
     "ListWorkflowsResponse",
     "MCPCheckInputRequest",
     "MCPCheckInputResponse",