From e6fcb0d8b580899c157bb65ac1c175df6c508299 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Wed, 20 May 2026 07:58:46 -0700
Subject: [PATCH 1/8] Add optional activity outcome in start activity response

---
 openapi/openapiv2.json                                 | 8 ++++++++
 openapi/openapiv3.yaml                                 | 7 +++++++
 temporal/api/workflowservice/v1/request_response.proto | 5 +++++
 3 files changed, 20 insertions(+)

diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 65437ff15..3adba52db 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -12173,6 +12173,10 @@
         "startDelay": {
           "type": "string",
           "description": "Time to wait before dispatching the first activity task. This delay is not applied to retry attempts."
+        },
+        "includeOutcome": {
+          "type": "boolean",
+          "description": "Include the outcome (result/failure) in the response if the activity has completed."
         }
       }
     },
@@ -18929,6 +18933,10 @@
         "link": {
           "$ref": "#/definitions/v1Link",
           "description": "Link to the started activity."
+        },
+        "outcome": {
+          "$ref": "#/definitions/v1ActivityExecutionOutcome",
+          "description": "Only set if the activity is already completed and include_outcome was true in the request."
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index bb733a194..931e6a32a 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -16349,6 +16349,9 @@ components:
           pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
           type: string
           description: Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
+        includeOutcome:
+          type: boolean
+          description: Include the outcome (result/failure) in the response if the activity has completed.
     StartActivityExecutionResponse:
       type: object
       properties:
@@ -16362,6 +16365,10 @@ components:
           allOf:
             - $ref: '#/components/schemas/Link'
           description: Link to the started activity.
+        outcome:
+          allOf:
+            - $ref: '#/components/schemas/ActivityExecutionOutcome'
+          description: Only set if the activity is already completed and include_outcome was true in the request.
     StartBatchOperationRequest:
       type: object
       properties:
diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 6d2d324a7..3e3c9a162 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -3164,6 +3164,9 @@ message StartActivityExecutionRequest {
     temporal.api.common.v1.OnConflictOptions on_conflict_options = 21;
     // Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
     google.protobuf.Duration start_delay = 22;
+
+    // Include the outcome (result/failure) in the response if the activity has completed.
+    bool include_outcome = 23;
 }
 
 message StartActivityExecutionResponse {
@@ -3173,6 +3176,8 @@ message StartActivityExecutionResponse {
     bool started = 2;
     // Link to the started activity.
     temporal.api.common.v1.Link link = 3;
+    // Only set if the activity is already completed and include_outcome was true in the request.
+    temporal.api.activity.v1.ActivityExecutionOutcome outcome = 4;
 }
 
 message DescribeActivityExecutionRequest {

From df33ca7b53cd20708f9b5e02a404fce62d2c3893 Mon Sep 17 00:00:00 2001
From: ks-temporal <281732484+ks-temporal@users.noreply.github.com>
Date: Tue, 26 May 2026 11:52:41 -0700
Subject: [PATCH 2/8] Update comment based on review

Co-authored-by: Fred Tzeng <41805201+fretz12@users.noreply.github.com>
---
 temporal/api/workflowservice/v1/request_response.proto | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 3e3c9a162..1b07a1d27 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -3165,7 +3165,7 @@ message StartActivityExecutionRequest {
     // Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
     google.protobuf.Duration start_delay = 22;
 
-    // Include the outcome (result/failure) in the response if the activity has completed.
+    // Include the outcome in the response if the activity has completed.
     bool include_outcome = 23;
 }
 

From 374277413014a38d1ec90da246f27cefc720a031 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Tue, 26 May 2026 12:05:03 -0700
Subject: [PATCH 3/8] Update comment based on review

---
 openapi/openapiv2.json | 2 +-
 openapi/openapiv3.yaml | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 2811d8c9c..9f5ed9064 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -12176,7 +12176,7 @@
         },
         "includeOutcome": {
           "type": "boolean",
-          "description": "Include the outcome (result/failure) in the response if the activity has completed."
+          "description": "Include the outcome in the response if the activity has completed."
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index 6579924c5..9c5f685dd 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -16367,7 +16367,7 @@ components:
           description: Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
         includeOutcome:
           type: boolean
-          description: Include the outcome (result/failure) in the response if the activity has completed.
+          description: Include the outcome in the response if the activity has completed.
     StartActivityExecutionResponse:
       type: object
       properties:

From b809f9ae27983935d7352c083f555f331c487219 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Thu, 28 May 2026 10:53:36 -0700
Subject: [PATCH 4/8] Update comment based on review

---
 temporal/api/workflowservice/v1/request_response.proto | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 1b07a1d27..0782fe909 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -3165,7 +3165,11 @@ message StartActivityExecutionRequest {
     // Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
     google.protobuf.Duration start_delay = 22;
 
-    // Include the outcome in the response if the activity has completed.
+    // Include the outcome in a success response if the activity has completed, and
+    // id_reuse_policy or id_conflict_policy would have caused a failure response otherwise.
+    // This is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,
+    // or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,
+    // or id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING.
     bool include_outcome = 23;
 }
 

From 677c499fc2daa89b3ad47cc4dddb970d1e03c950 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Thu, 28 May 2026 11:20:12 -0700
Subject: [PATCH 5/8] Update comment based on review

---
 openapi/openapiv2.json | 2 +-
 openapi/openapiv3.yaml | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 13d3b910a..724519f59 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -12176,7 +12176,7 @@
         },
         "includeOutcome": {
           "type": "boolean",
-          "description": "Include the outcome in the response if the activity has completed."
+          "description": "Include the outcome in a success response if the activity has completed, and\nid_reuse_policy or id_conflict_policy would have caused a failure response otherwise.\nThis is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,\nor the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,\nor id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING."
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index bf39f0178..08d0b5f89 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -16379,7 +16379,12 @@ components:
           description: Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
         includeOutcome:
           type: boolean
-          description: Include the outcome in the response if the activity has completed.
+          description: |-
+            Include the outcome in a success response if the activity has completed, and
+             id_reuse_policy or id_conflict_policy would have caused a failure response otherwise.
+             This is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,
+             or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,
+             or id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING.
     StartActivityExecutionResponse:
       type: object
       properties:

From 3b18f3ef4b8573bd61e85df57be6fa3e75bd191b Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Mon, 8 Jun 2026 13:14:40 -0700
Subject: [PATCH 6/8] Rename flag based on feedback to be more explicit.

---
 temporal/api/workflowservice/v1/request_response.proto | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index b91213dce..b78a9bac7 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -3171,11 +3171,10 @@ message StartActivityExecutionRequest {
     google.protobuf.Duration start_delay = 22;
 
     // Include the outcome in a success response if the activity has completed, and
-    // id_reuse_policy or id_conflict_policy would have caused a failure response otherwise.
+    // id_reuse_policy would have caused a failure response otherwise.
     // This is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,
-    // or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,
-    // or id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING.
-    bool include_outcome = 23;
+    // or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY.
+    bool id_reuse_policy_return_existing_outcome_on_reject = 23;
 }
 
 message StartActivityExecutionResponse {

From 3b82d448785cbace3f8d0469465bee0693ef2fb9 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Mon, 8 Jun 2026 13:39:41 -0700
Subject: [PATCH 7/8] Rename flag based on feedback to be more explicit

---
 openapi/openapiv2.json | 4 ++--
 openapi/openapiv3.yaml | 7 +++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 724519f59..13ec0c49c 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -12174,9 +12174,9 @@
           "type": "string",
           "description": "Time to wait before dispatching the first activity task. This delay is not applied to retry attempts."
         },
-        "includeOutcome": {
+        "idReusePolicyReturnExistingOutcomeOnReject": {
           "type": "boolean",
-          "description": "Include the outcome in a success response if the activity has completed, and\nid_reuse_policy or id_conflict_policy would have caused a failure response otherwise.\nThis is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,\nor the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,\nor id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING."
+          "description": "Include the outcome in a success response if the activity has completed, and\nid_reuse_policy would have caused a failure response otherwise.\nThis is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,\nor the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY."
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index 08d0b5f89..25f5aa464 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -16377,14 +16377,13 @@ components:
           pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
           type: string
           description: Time to wait before dispatching the first activity task. This delay is not applied to retry attempts.
-        includeOutcome:
+        idReusePolicyReturnExistingOutcomeOnReject:
           type: boolean
           description: |-
             Include the outcome in a success response if the activity has completed, and
-             id_reuse_policy or id_conflict_policy would have caused a failure response otherwise.
+             id_reuse_policy would have caused a failure response otherwise.
              This is applicable only when the id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_REJECT_DUPLICATE,
-             or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY,
-             or id_conflict_policy is ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING.
+             or the activity succeeded and id_reuse_policy is ACTIVITY_ID_REUSE_POLICY_ALLOW_DUPLICATE_FAILED_ONLY.
     StartActivityExecutionResponse:
       type: object
       properties:

From c2e3a1f59bd9d91e8fa442773cd02d22aa7fec05 Mon Sep 17 00:00:00 2001
From: Kundan <281732484+ks-temporal@users.noreply.github.com>
Date: Wed, 10 Jun 2026 21:23:17 -0700
Subject: [PATCH 8/8] Update comment on run_id, link and outcome based on
 review

---
 openapi/openapiv2.json                              |  6 +++---
 openapi/openapiv3.yaml                              | 13 ++++++++++---
 .../api/workflowservice/v1/request_response.proto   | 10 +++++++---
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 13ec0c49c..b1b88f950 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -18950,7 +18950,7 @@
       "properties": {
         "runId": {
           "type": "string",
-          "description": "The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING)."
+          "description": "The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING),\nor was already completed when request's id_reuse_policy_return_existing_outcome_on_reject\ncauses an outcome to be included in this response."
         },
         "started": {
           "type": "boolean",
@@ -18958,11 +18958,11 @@
         },
         "link": {
           "$ref": "#/definitions/v1Link",
-          "description": "Link to the started activity."
+          "description": "Link to the started activity - or an already completed activity when request's\nid_reuse_policy_return_existing_outcome_on_reject causes an outcome to be included in this."
         },
         "outcome": {
           "$ref": "#/definitions/v1ActivityExecutionOutcome",
-          "description": "Only set if the activity is already completed and include_outcome was true in the request."
+          "description": "Only set if the activity is already completed and id_reuse_policy_return_existing_outcome_on_reject\nwas true in the request. In that case it also populates the run_id and link for that activity."
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index 25f5aa464..331faa86c 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -16389,18 +16389,25 @@ components:
       properties:
         runId:
           type: string
-          description: The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING).
+          description: |-
+            The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING),
+             or was already completed when request's id_reuse_policy_return_existing_outcome_on_reject
+             causes an outcome to be included in this response.
         started:
           type: boolean
           description: If true, a new activity was started.
         link:
           allOf:
             - $ref: '#/components/schemas/Link'
-          description: Link to the started activity.
+          description: |-
+            Link to the started activity - or an already completed activity when request's
+             id_reuse_policy_return_existing_outcome_on_reject causes an outcome to be included in this.
         outcome:
           allOf:
             - $ref: '#/components/schemas/ActivityExecutionOutcome'
-          description: Only set if the activity is already completed and include_outcome was true in the request.
+          description: |-
+            Only set if the activity is already completed and id_reuse_policy_return_existing_outcome_on_reject
+             was true in the request. In that case it also populates the run_id and link for that activity.
     StartBatchOperationRequest:
       type: object
       properties:
diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index b78a9bac7..93fee05a1 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -3178,13 +3178,17 @@ message StartActivityExecutionRequest {
 }
 
 message StartActivityExecutionResponse {
-    // The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING).
+    // The run ID of the activity that was started - or used (via ACTIVITY_ID_CONFLICT_POLICY_USE_EXISTING),
+    // or was already completed when request's id_reuse_policy_return_existing_outcome_on_reject
+    // causes an outcome to be included in this response.
     string run_id = 1;
     // If true, a new activity was started.
     bool started = 2;
-    // Link to the started activity.
+    // Link to the started activity - or an already completed activity when request's
+    // id_reuse_policy_return_existing_outcome_on_reject causes an outcome to be included in this.
     temporal.api.common.v1.Link link = 3;
-    // Only set if the activity is already completed and include_outcome was true in the request.
+    // Only set if the activity is already completed and id_reuse_policy_return_existing_outcome_on_reject
+    // was true in the request. In that case it also populates the run_id and link for that activity.
     temporal.api.activity.v1.ActivityExecutionOutcome outcome = 4;
 }