# 7A - runtime_call_graph

## Runtime Steps (Code + Trace Evidence)

| Step | Runtime block | Code evidence | Trace evidence | Verification |
|---|---|---|---|---|
| S1 | API ingress | `backend/src/routes/assistant.ts` (`POST /api/assistant/message`, calls `assistantService.handleMessage`) | conversation exports contain per-turn `trace_id` and timestamps | verified |
| S2 | Follow-up binding | `backend/src/services/assistantService.ts` (`buildFollowupStateBinding`, around line 992) | investigation snapshot fields visible in exported debug payloads | partially verified |
| S3 | Normalization/router | `assistantService.ts` uses normalizer output and route summary | payload contains `route_summary`, `fragments`, `question_type_class` | verified |
| S4 | Execution plan | `assistantService.ts` `toExecutionPlan` (around line 339), invoked in main flow | payload has per-fragment `route` and `route_status` | verified |
| S5 | Retrieval runtime | `backend/src/services/assistantDataLayer.ts` `executeRouteRuntime` (around line 2520) | payload `retrieval_results` present per fragment | verified |
| S6 | Live overlay merge | `assistantDataLayer.ts` merges `live_mcp` into `summary` (around line 2550-2552) | traces show `live_mcp.fetched_rows/matched_rows/returned_rows` | verified |
| S7 | Coverage + grounding checks | `assistantService.ts` `evaluateCoverage`/`checkGrounding` (around lines 1255-1271) | payload has `coverage_report` and `answer_grounding_check` | verified |
| S8 | Answer composition | `assistantService.ts` calls `composeAssistantAnswer`; sanitization barriers around line 1282 | payload has `answer_structure_v11`; user-facing reply type persisted | verified |
| S9 | Investigation state update | `backend/src/services/investigationState.ts` used in service flow | `investigation_state_snapshot` present in debug payload | partially verified |
| S10 | Debug/export persistence | `assistantService.ts` emits debug payload fields and export-safe response | raw exports (`1.txt`,`2.txt`) include full technical blocks | verified |

## Notes

- Call chain existence is verified.
- Semantic correctness of interpretation/evidence is not guaranteed by call-chain verification alone and is audited in `7C/7D/7E`.