> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/harness-platform/3.0/harness-platform-resources/pipelines/pipeline-execution-graph.md).
# Understanding Execution Graph API
The Pipeline **Execution Graph API** provides a structured representation of a pipeline's execution in Harness. It details the flow, dependencies, statuses, and outcomes of tasks within a pipeline.
Use this API to retrieve execution details at various levels, including stages, steps, and specific nodes. You can extract execution metadata, output variables, task delegation information, and logs for debugging and analysis.
***
### What you will learn in this topic?
* How the [execution subgraph API endpoint](#api-endpoint) retrieves node-level execution details.
* How to [interpret the execution graph JSON response](#example-execution-graph-response).
* How to [extract output variables](#extract-output-variables-from-an-execution-subgraph) from the execution graph using HTTP steps.
***
### Get an execution subgraph
The Execution Subgraph API provides detailed information about a specific node's execution in the pipeline. Use this endpoint to retrieve the execution graph for a particular node within a pipeline execution.
{% hint style="info" %}
**NODE TYPE RESTRICTION**
If the `PIE_RESTRICT_SUBGRAPH_API_TO_STEP_GROUP` feature flag is enabled on your account, the API only works with step group nodes. Contact [Harness Support](mailto:support@harness.io) if you need to check the flag status or modify this behavior.
{% endhint %}
#### API endpoint
```bash
GET /executions/{executionId}/subgraph/{nodeExecutionId}
```
**Path parameters:**
* **executionId**: The ID of the execution.
* **nodeExecutionId**: The ID of the node within the execution whose subgraph details are to be fetched.
For more information, refer to [Pipeline Execution Details API](https://apidocs.harness.io/tag/Pipeline-Execution-Details/?_gl=1*smd27j*_gcl_au*MTMxODM4MjQ4LjE3MzYxODY4MjA.*_ga*MTE3NTQ1ODQ5Ny4xNzI4NDAwNDc3*_ga_46758J5H8P*MTczODIyNzY5OS4yNTAuMS4xNzM4MjI4OTI3LjYwLjAuMA..#operation/getExecutionSubGraphForNodeExecution).
#### Example execution graph response
The execution graph contains the following key elements:
* **Root Node**: The entry point of the pipeline execution.
* **Execution Nodes**: Represents individual steps such as script execution, API calls, or deployments.
* **Dependencies**: Defines relationships between nodes, including sequential or parallel execution.
* **Task Delegation**: Assigns tasks to worker agents or delegates for execution.
* **Status Tracking**: Monitors execution states (Success, Failed, Running, etc.).
* **Output Variables**: Captures and stores data produced by execution steps.
* **Logs**: Stores detailed execution logs for debugging and analysis.
The following example shows a JSON response from the execution graph API:
```json
{
"status": "SUCCESS",
"data": {
"executionGraph": {
"rootNodeId": "HWbn_nVGSByRRgwtex3H2A",
"nodeMap": {
"ovKqIaGkQo2iRsKWgtameg": {
"uuid": "ovKqIaGkQo2iRsKWgtameg",
"setupId": "nfeEKsfVSYi9iJfDz2OY2Q",
"name": "ShellScript_2",
"identifier": "ShellScript_2",
"baseFqn": "pipeline.stages.custom_stage.spec.execution.steps.ShellScript_2",
"outcomes": {
"output": {
"outputVariables": {}
}
},
"stepParameters": {
"uuid": "nfeEKsfVSYi9iJfDz2OY2Q",
"identifier": "ShellScript_2",
"name": "ShellScript_2",
"timeout": "10m",
"type": "ShellScript",
"spec": {
"outputVariables": {},
"environmentVariables": {},
"shell": "Bash",
"source": {
"uuid": "oUbMpp0WTImNqk5B0RuqOg",
"type": "Inline",
"spec": {
"script": "echo \necho "
}
},
"executionTarget": {}
}
},
"startTs": 1738237072505,
"endTs": 1738237075169,
"stepType": "ShellScript",
"status": "Success",
"failureInfo": {
"message": "",
"failureTypeList": [],
"responseMessages": []
},
"skipInfo": null,
"nodeRunInfo": {
"whenCondition": "<+OnStageSuccess>",
"evaluatedCondition": true,
"expressions": []
},
"retryNodeMetadata": null,
"executableResponses": [
{
"task": {
"taskId": "H5kWcK_2TjGvqknkCmiGOw-DEL",
"taskCategory": "DELEGATE_TASK_V2",
"logKeys": [
"accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage/level3:spec/level4:execution/level5:steps/level6:ShellScript_2-commandUnit:Execute"
],
"units": [],
"taskName": "SHELL_SCRIPT_TASK_NG"
}
}
],
"unitProgresses": [
{
"unitName": "Execute",
"status": "SUCCESS",
"startTime": "1738237073847",
"endTime": "1738237073854"
}
],
"progressData": {
"unitProgresses": [
{
"unitName": "Execute",
"status": "SUCCESS",
"startTime": "1738237073847",
"endTime": "1738237073854"
}
]
},
"delegateInfoList": [
{
"id": "8MQ151-eSbGOhgEr6VBl_g",
"name": "harnessci-cd-ng-prod",
"taskId": "H5kWcK_2TjGvqknkCmiGOw-DEL",
"taskName": "SHELL_SCRIPT_TASK_NG"
}
],
"interruptHistories": [],
"stepDetails": {},
"strategyMetadata": null,
"executionInputConfigured": false,
"logBaseKey": "accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage/level3:spec/level4:execution/level5:steps/level6:ShellScript_2"
},
"nxZXM3IuQqmwNO-UGR_PBw": {
"uuid": "nxZXM3IuQqmwNO-UGR_PBw",
"setupId": "T9PYhM5bThaBTQYkD7IplA",
"name": "ShellScript_1",
"identifier": "ShellScript_1",
"baseFqn": "pipeline.stages.custom_stage.spec.execution.steps.ShellScript_1",
"outcomes": {
"output": {
"outputVariables": {
"output1": "",
"output2": ""
}
}
},
"stepParameters": {
"uuid": "T9PYhM5bThaBTQYkD7IplA",
"identifier": "ShellScript_1",
"name": "ShellScript_1",
"timeout": "10m",
"type": "ShellScript",
"spec": {
"outputVariables": {
"output1": "hello",
"output2": "helloworld"
},
"environmentVariables": {},
"shell": "Bash",
"source": {
"uuid": "Dngv_Yz8Q26VhUiGoXbu1Q",
"type": "Inline",
"spec": {
"script": "echo hellp"
}
},
"executionTarget": {}
}
},
"startTs": 1738237068060,
"endTs": 1738237071106,
"stepType": "ShellScript",
"status": "Success",
"failureInfo": {
"message": "",
"failureTypeList": [],
"responseMessages": []
},
"skipInfo": null,
"nodeRunInfo": {
"whenCondition": "<+OnStageSuccess>",
"evaluatedCondition": true,
"expressions": []
},
"retryNodeMetadata": null,
"executableResponses": [
{
"task": {
"taskId": "Xr7qqhYvQJW1A5ONlZP6cA-DEL",
"taskCategory": "DELEGATE_TASK_V2",
"logKeys": [
"accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage/level3:spec/level4:execution/level5:steps/level6:ShellScript_1-commandUnit:Execute"
],
"units": [],
"taskName": "SHELL_SCRIPT_TASK_NG"
}
}
],
"unitProgresses": [
{
"unitName": "Execute",
"status": "SUCCESS",
"startTime": "1738237069178",
"endTime": "1738237069186"
}
],
"progressData": {
"unitProgresses": [
{
"unitName": "Execute",
"status": "SUCCESS",
"startTime": "1738237069178",
"endTime": "1738237069186"
}
]
},
"delegateInfoList": [
{
"id": "TYzuSpCfSIqRTcI_1NXhsw",
"name": "cd-cie",
"taskId": "Xr7qqhYvQJW1A5ONlZP6cA-DEL",
"taskName": "SHELL_SCRIPT_TASK_NG"
}
],
"interruptHistories": [],
"stepDetails": {},
"strategyMetadata": null,
"executionInputConfigured": false,
"logBaseKey": "accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage/level3:spec/level4:execution/level5:steps/level6:ShellScript_1"
},
"HWbn_nVGSByRRgwtex3H2A": {
"uuid": "HWbn_nVGSByRRgwtex3H2A",
"setupId": "UPu3J3RHSX2Ho9JiaEHgaw",
"name": "custom_stage",
"identifier": "custom_stage",
"baseFqn": "pipeline.stages.custom_stage",
"outcomes": {},
"stepParameters": {
"uuid": "UPu3J3RHSX2Ho9JiaEHgaw",
"identifier": "custom_stage",
"name": "custom_stage",
"description": "",
"variables": {},
"tags": {},
"type": "Custom",
"specConfig": {
"childNodeID": "UnUHvdf7RguBVTUWzRn47g"
},
"timeout": "35d"
},
"startTs": 1738237067731,
"endTs": 1738237075747,
"stepType": "CUSTOM_STAGE",
"status": "Success",
"failureInfo": {
"message": "",
"failureTypeList": [],
"responseMessages": []
},
"skipInfo": null,
"nodeRunInfo": {
"whenCondition": "<+OnPipelineSuccess>",
"evaluatedCondition": true,
"expressions": []
},
"retryNodeMetadata": null,
"executableResponses": [
{
"child": {
"childNodeId": "UnUHvdf7RguBVTUWzRn47g",
"logKeys": [],
"units": [],
"skip": false
}
}
],
"unitProgresses": [],
"progressData": {
"unitProgresses": []
},
"delegateInfoList": [],
"interruptHistories": [],
"stepDetails": {},
"strategyMetadata": null,
"executionInputConfigured": false,
"logBaseKey": "accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage"
},
"UGwyVIh2TwKo1Ff9ZWdiyA": {
"uuid": "UGwyVIh2TwKo1Ff9ZWdiyA",
"setupId": "eFx1JJDBTSG0KXToOZLW_Q",
"name": "Execution",
"identifier": "execution",
"baseFqn": "pipeline.stages.custom_stage.spec.execution",
"outcomes": {},
"stepParameters": {
"childNodeId": "eFx1JJDBTSG0KXToOZLW_Qsteps",
"logMessage": "Execution Element"
},
"startTs": 1738237067912,
"endTs": 1738237075453,
"stepType": "NG_SECTION_WITH_ROLLBACK_INFO",
"status": "Success",
"failureInfo": {
"message": "",
"failureTypeList": [],
"responseMessages": []
},
"skipInfo": null,
"nodeRunInfo": null,
"retryNodeMetadata": null,
"executableResponses": [
{
"child": {
"childNodeId": "eFx1JJDBTSG0KXToOZLW_Qsteps",
"logKeys": [],
"units": [],
"skip": false
}
}
],
"unitProgresses": [],
"progressData": {
"unitProgresses": []
},
"delegateInfoList": [],
"interruptHistories": [],
"stepDetails": {},
"strategyMetadata": null,
"executionInputConfigured": false,
"logBaseKey": "accountId:ACCOUNT_ID/orgId:ORG_ID/projectId:PROJECT_ID/pipelineId:output_variable/runSequence:1/level0:pipeline/level1:stages/level2:custom_stage/level3:spec/level4:execution"
}
},
"nodeAdjacencyListMap": {
"ovKqIaGkQo2iRsKWgtameg": {
"children": [],
"nextIds": []
},
"nxZXM3IuQqmwNO-UGR_PBw": {
"children": [],
"nextIds": [
"ovKqIaGkQo2iRsKWgtameg"
]
},
"HWbn_nVGSByRRgwtex3H2A": {
"children": [
"UGwyVIh2TwKo1Ff9ZWdiyA"
],
"nextIds": []
},
"UGwyVIh2TwKo1Ff9ZWdiyA": {
"children": [
"nxZXM3IuQqmwNO-UGR_PBw"
],
"nextIds": []
}
},
"executionMetadata": null,
"representationStrategy": "camelCase"
}
},
"metaData": null,
"correlationId": "7eafc0cb-411e-48e8-b1c7-4644ef7678e2"
}
```
***
### Extract output variables from an execution subgraph
You can extract output variables from the execution graph response JSON using an HTTP step and Shell script.
The following YAML example demonstrates how to retrieve output variables from a specific step:
```yaml
pipeline:
name: output_variable
identifier: output_variable
projectIdentifier: PROJECT_ID
orgIdentifier: ORG_ID
tags: {}
stages:
- stage:
name: custom_stage
identifier: custom_stage
description: ""
type: Custom
spec:
execution:
steps:
- step:
type: Http
name: Http_1
identifier: Http_1
spec:
url: https://app.harness.io/pipeline/api/pipelines/execution/subGraph/kC70LloTRcmoXkS5ffX4eg/HWbn_nVGSByRRgwtex3H2A?accountIdentifier=ACCOUNT_ID&orgIdentifier=ORG_ID&projectIdentifier=PROJECT_ID
method: GET
headers:
- key: x-api-key
value: PAT_TOKEN
- key: Content-Type
value: application/json
inputVariables: []
outputVariables:
- name: out_var
value: <+json.select(".data.executionGraph.nodeMap.nxZXM3IuQqmwNO-UGR_PBw.stepParameters.spec.outputVariables", httpResponseBody)>
type: String
timeout: 10s
- step:
type: ShellScript
name: ShellScript_1
identifier: ShellScript_1
spec:
shell: Bash
executionTarget: {}
source:
type: Inline
spec:
script: echo <+execution.steps.Http_1.output.outputVariables.out_var>
environmentVariables: []
outputVariables: []
timeout: 10m
tags: {}
```
You need to specify the specific step `uuid` if you want to extract output variables from a specific step. The same can be extracted from the JSON response.
#### Output
The Shell script step displays the extracted output variables from the execution graph.
***
### Next steps
* [Run specific stages](/harness-platform/3.0/harness-platform-resources/pipelines/run-specific-stage-in-pipeline.md): Select which stages to run during pipeline execution.
* [Runtime inputs](/harness-platform/3.0/harness-platform-resources/variables-and-expressions/runtime-inputs.md): Learn how runtime inputs and output variables work in pipelines.
* [Executions and logs](/harness-platform/3.0/harness-platform-resources/pipelines/executions-and-logs.md): View and analyze pipeline execution history and logs.
***