feat: implement call graph construction methods (fromCallEvents, updateFromEvent, addCall, addDependency, updateStatus, updateCall, removeCall)

src/graph/construction.ts

@@ -1,13 +1,16 @@
 import { DirectedGraph } from "graphology";
 import type { TSchema, Static } from "@alkdev/typebox";
+import { Value } from "@alkdev/typebox/value";
 import { willCreateCycle, topologicalSort, hasCycle } from "graphology-dag";
 import {
   DuplicateNodeError,
   DuplicateEdgeError,
   NodeNotFoundError,
   CycleError,
+  InvalidInputError,
+  InvalidTransitionError,
 } from "../error/index.js";
-import type { CallStatus, AnyValidationError } from "../error/index.js";
+import type { CallStatus, AnyValidationError, ValidationError } from "../error/index.js";
 import {
   findCycles,
   reachableFrom as reachableFromFn,
@@ -16,8 +19,12 @@ import { validate as _validate } from "./validation.js";
 import {
   OperationNodeAttrs as OperationNodeAttrsSchema,
   OperationEdgeAttrs as OperationEdgeAttrsSchema,
+  OperationGraphSerialized,
+  CallGraphSerialized,
+  CallNodeAttrs as CallNodeAttrsSchema,
+  CallEdgeAttrs as CallEdgeAttrsSchema,
 } from "../schema/index.js";
-import type { OperationNodeAttrs } from "../schema/index.js";
+import type { OperationNodeAttrs, FlowGraphSerialized, CallNodeAttrs } from "../schema/index.js";
 import { typeCompat, type TypeCompatResult } from "../analysis/type-compat.js";
 
 export interface FlowGraphOptions {
@@ -37,8 +44,55 @@ export interface OperationSpec {
   tags?: string[];
 }
 
+export interface CallRequestedEvent {
+  type: "call.requested";
+  requestId: string;
+  operationId: string;
+  input: unknown;
+  timestamp: string;
+  parentRequestId?: string;
+  identity?: { id: string; scopes: string[]; resources?: Record<string, string[]> };
+  startedAt?: string;
+}
+
+export interface CallRespondedEvent {
+  type: "call.responded";
+  requestId: string;
+  output: unknown;
+  timestamp: string;
+}
+
+export interface CallErrorEvent {
+  type: "call.error";
+  requestId: string;
+  error: { code: string; message: string; details?: unknown };
+  timestamp: string;
+}
+
+export interface CallAbortedEvent {
+  type: "call.aborted";
+  requestId: string;
+  timestamp: string;
+}
+
+export interface CallCompletedEvent {
+  type: "call.completed";
+  requestId: string;
+  output?: unknown;
+  timestamp: string;
+}
+
+export type CallEventMapValue =
+  | CallRequestedEvent
+  | CallRespondedEvent
+  | CallErrorEvent
+  | CallAbortedEvent
+  | CallCompletedEvent;
+
 type OperationGraph = FlowGraph<typeof OperationNodeAttrsSchema, typeof OperationEdgeAttrsSchema>;
 
+type CallGraph = FlowGraph<typeof CallNodeAttrsSchema, typeof CallEdgeAttrsSchema>;
+
 type TypedEdgeAttrs = {
   edgeType: "typed";
   compatible: boolean;
@@ -48,6 +102,14 @@ type TypedEdgeAttrs = {
 
 type Attrs = Record<string, unknown>;
 
+const VALID_TRANSITIONS: Record<CallStatus, CallStatus[]> = {
+  pending: ["running", "aborted"],
+  running: ["completed", "failed", "aborted"],
+  completed: [],
+  failed: [],
+  aborted: [],
+};
+
 export class FlowGraph<
   NodeAttrs extends TSchema = TSchema,
   EdgeAttrs extends TSchema = TSchema,
@@ -314,6 +376,145 @@ export class FlowGraph<
     return chain;
   }
 
+  updateFromEvent(event: CallEventMapValue): void {
+    switch (event.type) {
+      case "call.requested": {
+        const attrs: CallNodeAttrs = {
+          requestId: event.requestId,
+          operationId: event.operationId,
+          status: "pending",
+          input: event.input,
+          ...(event.parentRequestId !== undefined ? { parentRequestId: event.parentRequestId } : {}),
+          ...(event.identity !== undefined ? { identity: event.identity } : {}),
+          ...(event.startedAt !== undefined ? { startedAt: event.startedAt } : {}),
+        };
+        this.addCall(attrs);
+        break;
+      }
+      case "call.responded": {
+        if (!this._graph.hasNode(event.requestId)) return;
+        const current = this._graph.getNodeAttributes(event.requestId) as Record<string, unknown>;
+        const currentStatus = current.status as CallStatus;
+        if (currentStatus === "completed" || currentStatus === "failed" || currentStatus === "aborted") return;
+        this._graph.mergeNodeAttributes(event.requestId, {
+          status: "completed",
+          output: event.output,
+          completedAt: event.timestamp,
+        } as Attrs);
+        break;
+      }
+      case "call.error": {
+        if (!this._graph.hasNode(event.requestId)) return;
+        const current = this._graph.getNodeAttributes(event.requestId) as Record<string, unknown>;
+        const currentStatus = current.status as CallStatus;
+        if (currentStatus === "completed" || currentStatus === "failed" || currentStatus === "aborted") return;
+        this._graph.mergeNodeAttributes(event.requestId, {
+          status: "failed",
+          error: event.error,
+          completedAt: event.timestamp,
+        } as Attrs);
+        break;
+      }
+      case "call.aborted": {
+        if (!this._graph.hasNode(event.requestId)) return;
+        const current = this._graph.getNodeAttributes(event.requestId) as Record<string, unknown>;
+        const currentStatus = current.status as CallStatus;
+        if (currentStatus === "completed" || currentStatus === "failed" || currentStatus === "aborted") return;
+        this._graph.mergeNodeAttributes(event.requestId, {
+          status: "aborted",
+          completedAt: event.timestamp,
+        } as Attrs);
+        break;
+      }
+      case "call.completed": {
+        if (!this._graph.hasNode(event.requestId)) return;
+        const current = this._graph.getNodeAttributes(event.requestId) as Record<string, unknown>;
+        const currentStatus = current.status as CallStatus;
+        if (currentStatus === "completed") {
+          if (!current.completedAt) {
+            this._graph.mergeNodeAttributes(event.requestId, { completedAt: event.timestamp } as Attrs);
+          }
+          return;
+        }
+        if (currentStatus === "failed" || currentStatus === "aborted") return;
+        this._graph.mergeNodeAttributes(event.requestId, {
+          status: "completed",
+          ...(event.output !== undefined ? { output: event.output } : {}),
+          completedAt: event.timestamp,
+        } as Attrs);
+        break;
+      }
+    }
+  }
+
+  addCall(attrs: CallNodeAttrs): void {
+    if (this._graph.hasNode(attrs.requestId)) return;
+    this._graph.addNode(attrs.requestId, attrs as Attrs);
+    if (attrs.parentRequestId !== undefined) {
+      if (this._graph.hasNode(attrs.parentRequestId)) {
+        if (willCreateCycle(this._graph, attrs.parentRequestId, attrs.requestId)) {
+          this._graph.dropNode(attrs.requestId);
+          const path = this._findPath(attrs.requestId, attrs.parentRequestId);
+          const cycle = [attrs.parentRequestId, ...path, attrs.parentRequestId];
+          throw new CycleError([cycle]);
+        }
+        const edgeKey = this._edgeKey(attrs.parentRequestId, attrs.requestId);
+        this._graph.addEdgeWithKey(edgeKey, attrs.parentRequestId, attrs.requestId, { edgeType: "triggered" } as Attrs);
+      }
+    }
+  }
+
+  addDependency(source: string, target: string): void {
+    if (!this._graph.hasNode(source)) {
+      throw new NodeNotFoundError(source);
+    }
+    if (!this._graph.hasNode(target)) {
+      throw new NodeNotFoundError(target);
+    }
+    const edgeKey = `${source}->${target}:depends_on`;
+    if (this._graph.hasEdge(edgeKey)) return;
+    if (willCreateCycle(this._graph, source, target)) {
+      const path = this._findPath(target, source);
+      const cycle = [source, ...path, source];
+      throw new CycleError([cycle]);
+    }
+    this._graph.addEdgeWithKey(edgeKey, source, target, { edgeType: "depends_on" } as Attrs);
+  }
+
+  updateStatus(requestId: string, status: CallStatus, extra?: Partial<CallNodeAttrs>): void {
+    if (!this._graph.hasNode(requestId)) {
+      throw new NodeNotFoundError(requestId);
+    }
+    const current = this._graph.getNodeAttributes(requestId) as Record<string, unknown>;
+    const currentStatus = current.status as CallStatus;
+    if (currentStatus === status) return;
+    const allowed = VALID_TRANSITIONS[currentStatus];
+    if (!allowed || !allowed.includes(status)) {
+      throw new InvalidTransitionError(requestId, currentStatus, status);
+    }
+    const update: Record<string, unknown> = { status };
+    if (extra) {
+      for (const [key, value] of Object.entries(extra)) {
+        if (value !== undefined) {
+          update[key] = value;
+        }
+      }
+    }
+    this._graph.mergeNodeAttributes(requestId, update as Attrs);
+  }
+
+  updateCall(requestId: string, attrs: Partial<CallNodeAttrs>): void {
+    if (!this._graph.hasNode(requestId)) {
+      throw new NodeNotFoundError(requestId);
+    }
+    this._graph.mergeNodeAttributes(requestId, attrs as Attrs);
+  }
+
+  removeCall(requestId: string): void {
+    if (!this._graph.hasNode(requestId)) return;
+    this._graph.dropNode(requestId);
+  }
+
   validate(schema: TSchema): AnyValidationError[] {
     return _validate(this, schema as NodeAttrs);
   }
@@ -361,16 +562,72 @@ export class FlowGraph<
     return graph;
   }
 
-  static fromCallEvents(
+  static fromCallEvents(events: CallEventMapValue[]): CallGraph {
-    _events: unknown[],
+    const graph = new FlowGraph<typeof CallNodeAttrsSchema, typeof CallEdgeAttrsSchema>();
-  ): FlowGraph<TSchema, TSchema> {
+    for (const event of events) {
-    throw new Error("not implemented");
+      graph.updateFromEvent(event);
+    }
+    return graph;
+  }
+
+  export(): FlowGraphSerialized {
+    return this._graph.export() as unknown as FlowGraphSerialized;
+  }
+
+  toJSON(): FlowGraphSerialized {
+    return this.export();
+  }
+
+  toString(): string {
+    return JSON.stringify(this.export());
   }
 
   static fromJSON(
-    _data: unknown,
+    data: FlowGraphSerialized,
   ): FlowGraph<TSchema, TSchema> {
-    throw new Error("not implemented");
+    const opCheck = Value.Check(OperationGraphSerialized, data);
+    const callCheck = Value.Check(CallGraphSerialized, data);
+    if (!opCheck && !callCheck) {
+      const errors: ValidationError[] = [];
+      const opIter = Value.Errors(OperationGraphSerialized, data as Record<string, unknown>);
+      for (const err of opIter) {
+        errors.push({
+          type: "schema",
+          nodeKey: "",
+          field: err.path.replace(/^\//, "") || err.path,
+          message: err.message,
+          value: err.value,
+        });
+      }
+      if (errors.length === 0) {
+        const callIter = Value.Errors(CallGraphSerialized, data as Record<string, unknown>);
+        for (const err of callIter) {
+          errors.push({
+            type: "schema",
+            nodeKey: "",
+            field: err.path.replace(/^\//, "") || err.path,
+            message: err.message,
+            value: err.value,
+          });
+        }
+      }
+      throw new InvalidInputError(errors);
+    }
+
+    const fg = new FlowGraph<TSchema, TSchema>();
+    for (const node of data.nodes) {
+      fg._graph.addNode(node.key, node.attributes as Attrs);
+    }
+    for (const edge of data.edges) {
+      fg._graph.addEdgeWithKey(edge.key, edge.source, edge.target, edge.attributes as Attrs);
+    }
+
+    if (hasCycle(fg._graph)) {
+      const cycles = findCycles(fg._graph);
+      throw new CycleError(cycles);
+    }
+
+    return fg;
   }
 
   private _findPath(from: string, to: string): string[] {

src/graph/index.ts

@@ -1,4 +1,4 @@
-export { FlowGraph, buildTypeEdges, type FlowGraphOptions, type OperationSpec } from "./construction.js";
+export { FlowGraph, buildTypeEdges, type FlowGraphOptions, type OperationSpec, type CallEventMapValue, type CallRequestedEvent, type CallRespondedEvent, type CallErrorEvent, type CallAbortedEvent, type CallCompletedEvent } from "./construction.js";
 export {
   topologicalOrder,
   hasCycles,

src/index.ts

@@ -1,6 +1,6 @@
 export * from "./error/index.js";
 
-export { FlowGraph, buildTypeEdges, type FlowGraphOptions, type OperationSpec } from "./graph/index.js";
+export { FlowGraph, buildTypeEdges, type FlowGraphOptions, type OperationSpec, type CallEventMapValue, type CallRequestedEvent, type CallRespondedEvent, type CallErrorEvent, type CallAbortedEvent, type CallCompletedEvent } from "./graph/index.js";
 export {
   validateSchema,
   validateGraph,

test/graph/construction.test.ts

@@ -1,13 +1,15 @@
 import { describe, it, expect } from "vitest";
 import { Type } from "@alkdev/typebox";
 import { FlowGraph, buildTypeEdges } from "../../src/graph/construction.js";
-import type { OperationSpec } from "../../src/graph/construction.js";
+import type { OperationSpec, CallEventMapValue } from "../../src/graph/construction.js";
 import {
   DuplicateNodeError,
   DuplicateEdgeError,
   NodeNotFoundError,
   CycleError,
+  InvalidTransitionError,
 } from "../../src/error/index.js";
+import type { CallStatus } from "../../src/error/index.js";
 
 describe("FlowGraph constructor", () => {
   it("creates an empty graph", () => {
@@ -300,12 +302,14 @@ describe("FlowGraph query methods", () => {
 });
 
 describe("FlowGraph static stubs", () => {
-  it("fromCallEvents throws not implemented", () => {
+  it("fromCallEvents returns empty graph for empty events", () => {
-    expect(() => FlowGraph.fromCallEvents([])).toThrow("not implemented");
+    const graph = FlowGraph.fromCallEvents([]);
+    expect(graph.order).toBe(0);
+    expect(graph.size).toBe(0);
   });
 
   it("fromJSON throws not implemented", () => {
-    expect(() => FlowGraph.fromJSON({})).toThrow("not implemented");
+    expect(() => FlowGraph.fromJSON({} as never)).toThrow();
   });
 });
 
@@ -638,4 +642,520 @@ describe("FlowGraph cycle detection", () => {
     fg.addEdge("a", "c");
     expect(() => fg.addEdge("b", "c")).not.toThrow();
   });
+});
+
+describe("FlowGraph.fromCallEvents", () => {
+  const requestedEvent: CallEventMapValue = {
+    type: "call.requested",
+    requestId: "req-1",
+    operationId: "task.classify",
+    input: { text: "hello" },
+    timestamp: "2026-01-01T00:00:00Z",
+  };
+
+  const requestedWithParent: CallEventMapValue = {
+    type: "call.requested",
+    requestId: "req-2",
+    operationId: "task.enrich",
+    input: { label: "greeting" },
+    timestamp: "2026-01-01T00:00:01Z",
+    parentRequestId: "req-1",
+  };
+
+  const respondedEvent: CallEventMapValue = {
+    type: "call.responded",
+    requestId: "req-1",
+    output: { label: "greeting" },
+    timestamp: "2026-01-01T00:00:02Z",
+  };
+
+  const errorEvent: CallEventMapValue = {
+    type: "call.error",
+    requestId: "req-1",
+    error: { code: "INTERNAL", message: "Something went wrong" },
+    timestamp: "2026-01-01T00:00:03Z",
+  };
+
+  const abortedEvent: CallEventMapValue = {
+    type: "call.aborted",
+    requestId: "req-1",
+    timestamp: "2026-01-01T00:00:04Z",
+  };
+
+  const completedEvent: CallEventMapValue = {
+    type: "call.completed",
+    requestId: "req-1",
+    output: { label: "greeting" },
+    timestamp: "2026-01-01T00:00:05Z",
+  };
+
+  it("adds node from call.requested event", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent]);
+    expect(graph.order).toBe(1);
+    expect(graph.hasNode("req-1")).toBe(true);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("pending");
+    expect(attrs.operationId).toBe("task.classify");
+  });
+
+  it("creates triggered edge from parentRequestId", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, requestedWithParent]);
+    expect(graph.order).toBe(2);
+    expect(graph.hasNode("req-2")).toBe(true);
+    expect(graph.hasEdge("req-1", "req-2")).toBe(true);
+    const edgeAttrs = graph.getEdgeAttributes("req-1", "req-2") as Record<string, unknown>;
+    expect(edgeAttrs.edgeType).toBe("triggered");
+  });
+
+  it("updates status to completed on call.responded", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, respondedEvent]);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+    expect(attrs.output).toEqual({ label: "greeting" });
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:02Z");
+  });
+
+  it("updates status to failed on call.error", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, errorEvent]);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("failed");
+    expect(attrs.error).toEqual({ code: "INTERNAL", message: "Something went wrong" });
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:03Z");
+  });
+
+  it("updates status to aborted on call.aborted", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, abortedEvent]);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("aborted");
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:04Z");
+  });
+
+  it("updates status to completed on call.completed", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, completedEvent]);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:05Z");
+  });
+
+  it("is idempotent — duplicate events have no effect", () => {
+    const graph = FlowGraph.fromCallEvents([requestedEvent, requestedEvent, respondedEvent, respondedEvent]);
+    expect(graph.order).toBe(1);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+  });
+
+  it("ignores responded/error/aborted for unknown requestId", () => {
+    const graph = FlowGraph.fromCallEvents([respondedEvent, errorEvent, abortedEvent]);
+    expect(graph.order).toBe(0);
+  });
+
+  it("creates node for unknown operationId", () => {
+    const unknownOpEvent: CallEventMapValue = {
+      type: "call.requested",
+      requestId: "req-unknown",
+      operationId: "unknown.op",
+      input: {},
+      timestamp: "2026-01-01T00:00:00Z",
+    };
+    const graph = FlowGraph.fromCallEvents([unknownOpEvent]);
+    expect(graph.order).toBe(1);
+    const attrs = graph.getNodeAttributes("req-unknown") as Record<string, unknown>;
+    expect(attrs.status).toBe("pending");
+    expect(attrs.operationId).toBe("unknown.op");
+  });
+
+  it("processes full event sequence", () => {
+    const req1: CallEventMapValue = {
+      type: "call.requested",
+      requestId: "req-parent",
+      operationId: "task.parent",
+      input: {},
+      timestamp: "2026-01-01T00:00:00Z",
+    };
+    const req2: CallEventMapValue = {
+      type: "call.requested",
+      requestId: "req-child",
+      operationId: "task.child",
+      input: {},
+      timestamp: "2026-01-01T00:00:01Z",
+      parentRequestId: "req-parent",
+    };
+    const resp: CallEventMapValue = {
+      type: "call.responded",
+      requestId: "req-parent",
+      output: "done",
+      timestamp: "2026-01-01T00:00:02Z",
+    };
+    const graph = FlowGraph.fromCallEvents([req1, req2, resp]);
+    expect(graph.order).toBe(2);
+    expect(graph.hasEdge("req-parent", "req-child")).toBe(true);
+    const parentAttrs = graph.getNodeAttributes("req-parent") as Record<string, unknown>;
+    expect(parentAttrs.status).toBe("completed");
+    const childAttrs = graph.getNodeAttributes("req-child") as Record<string, unknown>;
+    expect(childAttrs.status).toBe("pending");
+  });
+
+  it("stores identity and startedAt from call.requested", () => {
+    const event: CallEventMapValue = {
+      type: "call.requested",
+      requestId: "req-id",
+      operationId: "task.op",
+      input: {},
+      timestamp: "2026-01-01T00:00:00Z",
+      identity: { id: "user-1", scopes: ["read"] },
+      startedAt: "2026-01-01T00:00:01Z",
+    };
+    const graph = FlowGraph.fromCallEvents([event]);
+    const attrs = graph.getNodeAttributes("req-id") as Record<string, unknown>;
+    expect(attrs.identity).toEqual({ id: "user-1", scopes: ["read"] });
+    expect(attrs.startedAt).toBe("2026-01-01T00:00:01Z");
+  });
+
+  it("skips triggered edge if parent node does not exist", () => {
+    const orphanEvent: CallEventMapValue = {
+      type: "call.requested",
+      requestId: "req-orphan",
+      operationId: "task.child",
+      input: {},
+      timestamp: "2026-01-01T00:00:00Z",
+      parentRequestId: "req-nonexistent",
+    };
+    const graph = FlowGraph.fromCallEvents([orphanEvent]);
+    expect(graph.order).toBe(1);
+    expect(graph.hasNode("req-orphan")).toBe(true);
+    expect(graph.size).toBe(0);
+  });
+});
+
+describe("FlowGraph.updateFromEvent", () => {
+  it("processes single event for real-time pattern", () => {
+    const graph = new FlowGraph();
+    graph.updateFromEvent({
+      type: "call.requested",
+      requestId: "req-1",
+      operationId: "task.classify",
+      input: { text: "hello" },
+      timestamp: "2026-01-01T00:00:00Z",
+    });
+    expect(graph.hasNode("req-1")).toBe(true);
+
+    graph.updateFromEvent({
+      type: "call.responded",
+      requestId: "req-1",
+      output: { label: "hi" },
+      timestamp: "2026-01-01T00:00:02Z",
+    });
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+    expect(attrs.output).toEqual({ label: "hi" });
+  });
+
+  it("ignores events for unknown requestId", () => {
+    const graph = new FlowGraph();
+    graph.updateFromEvent({
+      type: "call.responded",
+      requestId: "unknown",
+      output: "x",
+      timestamp: "2026-01-01T00:00:00Z",
+    });
+    expect(graph.order).toBe(0);
+  });
+
+  it("ignores terminal event re-processing", () => {
+    const graph = new FlowGraph();
+    graph.updateFromEvent({
+      type: "call.requested",
+      requestId: "req-1",
+      operationId: "task.op",
+      input: {},
+      timestamp: "2026-01-01T00:00:00Z",
+    });
+    graph.updateFromEvent({
+      type: "call.responded",
+      requestId: "req-1",
+      output: "done",
+      timestamp: "2026-01-01T00:00:01Z",
+    });
+    graph.updateFromEvent({
+      type: "call.error",
+      requestId: "req-1",
+      error: { code: "X", message: "Y" },
+      timestamp: "2026-01-01T00:00:02Z",
+    });
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+  });
+});
+
+describe("FlowGraph.addCall", () => {
+  it("adds a call node", () => {
+    const graph = new FlowGraph();
+    graph.addCall({
+      requestId: "req-1",
+      operationId: "task.classify",
+      status: "pending",
+      input: { text: "hello" },
+    });
+    expect(graph.hasNode("req-1")).toBe(true);
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("pending");
+  });
+
+  it("adds triggered edge when parentRequestId is present", () => {
+    const graph = new FlowGraph();
+    graph.addCall({
+      requestId: "req-parent",
+      operationId: "task.parent",
+      status: "pending",
+      input: {},
+    });
+    graph.addCall({
+      requestId: "req-child",
+      operationId: "task.child",
+      status: "pending",
+      input: {},
+      parentRequestId: "req-parent",
+    });
+    expect(graph.hasEdge("req-parent", "req-child")).toBe(true);
+    const edgeAttrs = graph.getEdgeAttributes("req-parent", "req-child") as Record<string, unknown>;
+    expect(edgeAttrs.edgeType).toBe("triggered");
+  });
+
+  it("is idempotent — duplicate addCall is ignored", () => {
+    const graph = new FlowGraph();
+    graph.addCall({
+      requestId: "req-1",
+      operationId: "task.op",
+      status: "pending",
+      input: {},
+    });
+    graph.addCall({
+      requestId: "req-1",
+      operationId: "task.op",
+      status: "pending",
+      input: {},
+    });
+    expect(graph.order).toBe(1);
+  });
+
+  it("does not throw if parentRequestId node does not exist", () => {
+    const graph = new FlowGraph();
+    graph.addCall({
+      requestId: "req-child",
+      operationId: "task.child",
+      status: "pending",
+      input: {},
+      parentRequestId: "nonexistent",
+    });
+    expect(graph.hasNode("req-child")).toBe(true);
+    expect(graph.size).toBe(0);
+  });
+});
+
+describe("FlowGraph.addDependency", () => {
+  it("creates depends_on edge", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.a", status: "pending", input: {} });
+    graph.addCall({ requestId: "req-2", operationId: "task.b", status: "pending", input: {} });
+    graph.addDependency("req-1", "req-2");
+    const edgeKey = "req-1->req-2:depends_on";
+    expect(graph.graph.hasEdge(edgeKey)).toBe(true);
+    const attrs = graph.graph.getEdgeAttributes(edgeKey) as Record<string, unknown>;
+    expect(attrs.edgeType).toBe("depends_on");
+  });
+
+  it("is idempotent — duplicate addDependency is ignored", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.a", status: "pending", input: {} });
+    graph.addCall({ requestId: "req-2", operationId: "task.b", status: "pending", input: {} });
+    graph.addDependency("req-1", "req-2");
+    graph.addDependency("req-1", "req-2");
+    expect(graph.graph.hasEdge("req-1->req-2:depends_on")).toBe(true);
+  });
+
+  it("throws NodeNotFoundError if source doesn't exist", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-2", operationId: "task.b", status: "pending", input: {} });
+    expect(() => graph.addDependency("missing", "req-2")).toThrow(NodeNotFoundError);
+  });
+
+  it("throws NodeNotFoundError if target doesn't exist", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.a", status: "pending", input: {} });
+    expect(() => graph.addDependency("req-1", "missing")).toThrow(NodeNotFoundError);
+  });
+
+  it("throws CycleError if adding would create cycle", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.a", status: "pending", input: {} });
+    graph.addCall({ requestId: "req-2", operationId: "task.b", status: "pending", input: {} });
+    graph.addCall({ requestId: "req-3", operationId: "task.c", status: "pending", input: {} });
+    graph.addEdge("req-1", "req-2");
+    graph.addEdge("req-2", "req-3");
+    expect(() => graph.addDependency("req-3", "req-1")).toThrow(CycleError);
+  });
+});
+
+describe("FlowGraph.updateStatus", () => {
+  it("transitions pending to running", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("running");
+  });
+
+  it("transitions running to completed", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "completed", { completedAt: "2026-01-01T00:00:01Z" });
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:01Z");
+  });
+
+  it("transitions running to failed", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "failed");
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("failed");
+  });
+
+  it("transitions pending to aborted", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "aborted");
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("aborted");
+  });
+
+  it("transitions running to aborted", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "aborted");
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("aborted");
+  });
+
+  it("is no-op if status is already the target", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "pending");
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("pending");
+  });
+
+  it("throws InvalidTransitionError for completed to running", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "completed", { completedAt: "2026-01-01T00:00:01Z" });
+    expect(() => graph.updateStatus("req-1", "running")).toThrow(InvalidTransitionError);
+  });
+
+  it("throws InvalidTransitionError for failed to running", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "failed");
+    expect(() => graph.updateStatus("req-1", "running")).toThrow(InvalidTransitionError);
+  });
+
+  it("throws InvalidTransitionError for aborted to running", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "aborted");
+    expect(() => graph.updateStatus("req-1", "running")).toThrow(InvalidTransitionError);
+  });
+
+  it("throws InvalidTransitionError for pending to completed", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    expect(() => graph.updateStatus("req-1", "completed")).toThrow(InvalidTransitionError);
+  });
+
+  it("throws InvalidTransitionError for pending to failed", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    expect(() => graph.updateStatus("req-1", "failed")).toThrow(InvalidTransitionError);
+  });
+
+  it("throws NodeNotFoundError for unknown requestId", () => {
+    const graph = new FlowGraph();
+    expect(() => graph.updateStatus("missing", "running")).toThrow(NodeNotFoundError);
+  });
+
+  it("InvalidTransitionError contains from/to info", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "completed", { completedAt: "2026-01-01T00:00:01Z" });
+    try {
+      graph.updateStatus("req-1", "running");
+      expect.unreachable("should throw");
+    } catch (e) {
+      expect(e).toBeInstanceOf(InvalidTransitionError);
+      const ite = e as InvalidTransitionError;
+      expect(ite.requestId).toBe("req-1");
+      expect(ite.from).toBe("completed" as CallStatus);
+      expect(ite.to).toBe("running" as CallStatus);
+    }
+  });
+
+  it("merges extra attributes on transition", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.op", status: "pending", input: {} });
+    graph.updateStatus("req-1", "running");
+    graph.updateStatus("req-1", "completed", {
+      output: { result: 42 },
+      completedAt: "2026-01-01T00:00:01Z",
+    });
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.status).toBe("completed");
+    expect(attrs.output).toEqual({ result: 42 });
+    expect(attrs.completedAt).toBe("2026-01-01T00:00:01Z");
+  });
+});
+
+describe("FlowGraph.updateCall", () => {
+  it("partially merges call attributes", () => {
+    const graph = new FlowGraph();
+    graph.addCall({
+      requestId: "req-1",
+      operationId: "task.op",
+      status: "pending",
+      input: {},
+    });
+    graph.updateCall("req-1", { output: "some result" });
+    const attrs = graph.getNodeAttributes("req-1") as Record<string, unknown>;
+    expect(attrs.output).toBe("some result");
+    expect(attrs.status).toBe("pending");
+  });
+
+  it("throws NodeNotFoundError for unknown requestId", () => {
+    const graph = new FlowGraph();
+    expect(() => graph.updateCall("missing", { output: "x" })).toThrow(NodeNotFoundError);
+  });
+});
+
+describe("FlowGraph.removeCall", () => {
+  it("removes node and attached edges", () => {
+    const graph = new FlowGraph();
+    graph.addCall({ requestId: "req-1", operationId: "task.parent", status: "pending", input: {} });
+    graph.addCall({ requestId: "req-2", operationId: "task.child", status: "pending", input: {}, parentRequestId: "req-1" });
+    expect(graph.size).toBe(1);
+    graph.removeCall("req-2");
+    expect(graph.hasNode("req-2")).toBe(false);
+    expect(graph.size).toBe(0);
+    expect(graph.hasNode("req-1")).toBe(true);
+  });
+
+  it("is a no-op if requestId doesn't exist", () => {
+    const graph = new FlowGraph();
+    expect(() => graph.removeCall("missing")).not.toThrow();
+  });
 });