1# Durable Functions Recipe
2 
3Orchestration workflows with Durable Task Scheduler as the backend.
4 
5## Template Selection
6 
7Resource filter: `durable`  
8Discover templates via MCP or CDN manifest where `resource == "durable"` and `language` matches user request.
9 
10## Key Concept
11 
12Uses **Durable Task Scheduler** (DTS) — a fully managed backend for state persistence. Do NOT use Azure Storage queues/tables.
13 
14See [Durable Task Scheduler reference](../../../../durable-task-scheduler/README.md) for backend configuration details.
15 
16## Troubleshooting
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18### Orchestration Fails to Start
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20**Cause:** Durable Task Scheduler (DTS) backend not provisioned or connection misconfigured.  
21**Solution:** Verify the DTS resource exists and the function app has the `Durable Task Scheduler Worker` role. Do NOT use Azure Storage queues/tables as backend.
22 
23### UAMI Connection Issues
24 
25**Cause:** Missing or incorrect Durable Task Scheduler connection string.  
26**Solution:** DTS uses a connection string format (not the `__` suffix pattern). Set these app settings:
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28- `DURABLE_TASK_SCHEDULER_CONNECTION_STRING`: `Endpoint=<scheduler-endpoint>;Authentication=ManagedIdentity;ClientID=<client-id>`
29- `TASKHUB_NAME`: name of the task hub
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31For system-assigned identity, omit `ClientID`:
32`Endpoint=<scheduler-endpoint>;Authentication=ManagedIdentity`
33 
34The identity must have the **Durable Task Data Contributor** role on the scheduler or task hub resource. See [DTS identity auth](https://learn.microsoft.com/en-us/azure/durable-task/scheduler/durable-task-scheduler-identity) for identity-based config — refer to the **"Configure managed identity"** section for connection string and role assignment details.
35 
36## Eval
37 
38| Path | Description |
39|------|-------------|
40| [eval/summary.md](eval/summary.md) | Evaluation summary |
41| [eval/python.md](eval/python.md) | Python evaluation results |
42