fix(agent): preserve complete model usage pricing

[zyssyz123]

Summary

• preserve the complete Graphon LLMUsage returned by plugin daemon model calls instead of reducing it to token counts
• aggregate pricing and timing metadata across streaming, tool-call, and retry rounds without double-counting cumulative stream usage
• emit the complete usage payload from Agent backend so Agent App messages and Workflow Agent nodes persist token prices, total price, currency, and latency
• keep backward compatibility when replaying older token-only Agent events

Root cause

The Agent model adapter converted plugin daemon LLMUsage into Pydantic AI RequestUsage, which only carries token counts. The terminal Agent event therefore omitted pricing fields. API reconstructed LLMUsage from that incomplete payload and persisted total_price = 0, so Agent Monitor correctly aggregated a zero database value.

Verification

• Dify Agent targeted tests: 79 passed
• API event adapter, Agent App runner, and Workflow Agent output adapter: 68 passed
• Ruff: passed
• basedpyright on changed production files: 0 errors
• dev deployment from deploy/agent verified both Agent backend and API/worker images use the fix commit
• dev Agent App SSE + history + database + Monitor E2E: 5,368 tokens / $0.027165
• dev multi-round knowledge tool E2E (knowledge_base_search): aggregated 11,401 tokens / $0.05853, matching persisted message usage
• dev Workflow Agent Node E2E: node and workflow completed with 6,412 tokens / $0.040760, matching node execution metadata

Linear: https://linear.app/dify/issue/DIFY-2815/agent-monitor-%E7%9A%84-token-usage-%E6%98%BE%E7%A4%BA%E9%97%AE%E9%A2%98

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-07-20 07:49:06.884176334 +0000
+++ /tmp/pyrefly_pr.txt	2026-07-20 07:49:02.088167554 +0000
@@ -1763,17 +1763,17 @@
 ERROR Argument `dict[str, object]` is not assignable to parameter `configs` with type `Mapping[str, LayerConfigInput] | None` in function `agenton.compositor.core.Compositor._create_run` [bad-argument-type]
   --> tests/unit_tests/clients/agent_backend/test_cleanup_composition_compositor_integration.py:97:17
 ERROR Cannot index into `bool` [bad-index]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR Cannot index into `float` [bad-index]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR Cannot index into `int` [bad-index]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR Cannot index into `list[JsonValue]` [bad-index]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR Cannot index into `str` [bad-index]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR `None` is not subscriptable [unsupported-operation]
-  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:55:12
+  --> tests/unit_tests/clients/agent_backend/test_event_adapter.py:57:12
 ERROR Object of class `list` has no attribute `startswith` [missing-attribute]
    --> tests/unit_tests/clients/agent_backend/test_request_builder.py:159:12
 ERROR Class member `_FailedStatusClient.wait_run` overrides a member in a parent class but is missing an `@override` decorator [missing-override-decorator]
@@ -3180,29 +3180,37 @@
 ERROR Object of class `FunctionType` has no attribute `return_value` [missing-attribute]
    --> tests/unit_tests/core/app/apps/agent_app/test_app_generator.py:465:25
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:563:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:576:12
 ERROR Object of class `NoneType` has no attribute `model` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:564:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:577:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:646:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:659:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:666:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:679:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:713:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:726:12
 ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:714:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:727:12
 ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:715:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:728:12
 ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:716:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:729:12
+ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:730:12
+ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:731:12
+ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:732:12
+ERROR Object of class `NoneType` has no attribute `usage` [missing-attribute]
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:733:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:737:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:754:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:755:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:772:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:773:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:790:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
-   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:794:12
+   --> tests/unit_tests/core/app/apps/agent_app/test_app_runner.py:811:12
 ERROR Object of class `NoneType` has no attribute `message` [missing-attribute]
   --> tests/unit_tests/core/app/apps/agent_app/test_input_guards.py:67:12
 ERROR Object of class `NoneType` has no attribute `prompt_messages` [missing-attribute]
@@ -6304,7 +6312,7 @@
 ERROR Cannot index into `dict[str, JsonValue]` [bad-index]
    --> tests/unit_tests/core/workflow/nodes/agent_v2/test_dify_tools_builder.py:393:43
 ERROR Argument `object` is not assignable to parameter `output` with type `Decimal | Iterable[Any] | Mapping[str, Any] | bool | bytearray | bytes | float | int | str | None` in function `clients.agent_backend.event_adapter.AgentBackendRunSucceededInternalEvent.__init__` [bad-argument-type]
-  --> tests/unit_tests/core/workflow/nodes/agent_v2/test_output_adapter.py:49:16
+  --> tests/unit_tests/core/workflow/nodes/agent_v2/test_output_adapter.py:50:16
 ERROR Object of class `FromClause` has no attribute `create` [missing-attribute]
   --> tests/unit_tests/core/workflow/nodes/agent_v2/test_output_file_rebacker.py:22:5
 ERROR Cannot index into `object` [bad-index]

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	54.08%	54.08%	0.00%
Strict coverage	53.56%	53.56%	0.00%
Typed symbols	34,505	34,505	0
Untyped symbols	29,585	29,585	0
Modules	3029	3029	0

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.68%. Comparing base (f93a5b9) to head (bd13c98).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #39201      +/-   ##
==========================================
- Coverage   85.73%   85.68%   -0.06%     
==========================================
  Files        5122     4960     -162     
  Lines      281146   276518    -4628     
  Branches    55277    54055    -1222     
==========================================
- Hits       241036   236923    -4113     
+ Misses      35497    34983     -514     
+ Partials     4613     4612       -1     

Flag	Coverage Δ
api	86.00% <ø> (+<0.01%)	⬆️
cli	?

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