---
id: graph/construction-call
name: Implement call graph construction (fromCallEvents, updateFromEvent, addCall, addDependency, updateStatus)
status: pending
depends_on:
  - graph/flowgraph-class
  - schema/enums
scope: broad
risk: high
impact: phase
level: implementation
---

## Description

Implement the construction and mutation methods for call graphs: `FlowGraph.fromCallEvents()`, `updateFromEvent()`, `addCall()`, `addDependency()`, `updateStatus()`, `updateCall()`, and `removeCall()`. These handle the dynamic call graph populated from call protocol events.

## Acceptance Criteria

- [ ] `FlowGraph.fromCallEvents(events: CallEventMapValue[]): CallGraph` — processes events in order, idempotent (duplicate events have no effect)
- [ ] Event processing: `call.requested` → add node (status: "pending", add triggered edge if parentRequestId), `call.responded` → status: "completed" + output + completedAt, `call.error` → status: "failed" + error + completedAt, `call.aborted` → status: "aborted" + completedAt, `call.completed` → status: "completed" + completedAt
- [ ] `updateFromEvent(event: CallEventMapValue): void` — single event processing for real-time subscription
- [ ] `addCall(attrs: CallNodeAttrs): void` — adds call node; if `parentRequestId` present, creates triggered edge from parent to child
- [ ] `addDependency(source, target): void` — creates depends_on edge with composite key `${source}->${target}:depends_on`
- [ ] `updateStatus(requestId, status, extra?): void` — validates transition per state machine, throws `InvalidTransitionError` on invalid transition
- [ ] `updateCall(requestId, attrs): void` — partial merge of call attributes
- [ ] `removeCall(requestId): void` — removes node and all attached edges
- [ ] Status transition validation: pending→running→completed/failed, pending→aborted, running→aborted (terminal states: completed, failed, aborted)
- [ ] Call graph errors are resilient: unknown requestId in responded/error/aborted → log warning, ignore; unknown operationId → create node anyway with status "pending"
- [ ] Unit tests: fromCallEvents with full event sequences, updateFromEvent real-time pattern, addCall with/without parent, status transitions valid/invalid, addDependency, idempotency

## References

- docs/architecture/call-graph.md — fromCallEvents, updateFromEvent, status lifecycle, mutations, abort cascading
- docs/architecture/schema.md — CallEventMapValue mapping to CallNodeAttrs, edge key convention
- docs/architecture/error-handling.md — call graph error boundary, InvalidTransitionError

## Notes

> To be filled by implementation agent

## Summary

> To be filled on completion