Add communication account plugin scaffolds

packages/account-core/src/policy.ts

@@ -0,0 +1,92 @@
+import { isPolicyGatedPermission } from "./permissions.js";
+import type { LogicSrcPolicyEvaluationInput, LogicSrcPolicyEvaluationResult, LogicSrcRiskBand } from "./types.js";
+
+const WRITE_ACTIONS = new Set([
+  "social:post:publish",
+  "social:post:delete",
+  "social:dm:send",
+  "email:send",
+  "email:reply",
+  "email:forward",
+  "email:delete",
+  "email:labels:modify",
+  "email:archive"
+]);
+
+export function riskBandForScore(score: number): LogicSrcRiskBand {
+  if (score >= 0.75) {
+    return "critical";
+  }
+  if (score >= 0.5) {
+    return "high";
+  }
+  if (score >= 0.25) {
+    return "medium";
+  }
+  return "low";
+}
+
+export function scoreAccountActionRisk(input: {
+  action: string;
+  externalRecipientCount?: number;
+  newRecipientOrDomain?: boolean;
+  hasAttachment?: boolean;
+  highReachAccount?: boolean;
+  sensitiveKeywordDetected?: boolean;
+  rawCredentialAccessAttempted?: boolean;
+}) {
+  let score = 0;
+
+  if (input.externalRecipientCount && input.externalRecipientCount > 0) score += 0.1;
+  if (input.newRecipientOrDomain) score += 0.15;
+  if (input.hasAttachment) score += 0.15;
+  if (input.action === "social:post:publish") score += 0.2;
+  if (input.action.includes("delete")) score += 0.2;
+  if (input.action.includes("dm:read") || input.action.includes("attachments:read")) score += 0.25;
+  if (input.highReachAccount) score += 0.25;
+  if (input.sensitiveKeywordDetected) score += 0.3;
+  if (input.rawCredentialAccessAttempted) score += 0.4;
+
+  return Math.min(1, Number(score.toFixed(2)));
+}
+
+export function evaluateAccountPolicy(input: LogicSrcPolicyEvaluationInput): LogicSrcPolicyEvaluationResult {
+  const riskScore = Math.min(1, Math.max(0, input.riskScore ?? scoreAccountActionRisk({ action: input.action })));
+  const grantActive = input.grant && !input.grant.revokedAt && (!input.grant.expiresAt || Date.parse(input.grant.expiresAt) > Date.now());
+  const hasPermission = Boolean(grantActive && input.grant?.permissions.includes(input.action));
+
+  if (!hasPermission) {
+    return { decision: "deny", riskScore, reason: `missing grant for ${input.action}` };
+  }
+
+  if (input.dryRun) {
+    return { decision: "allow", riskScore, reason: "dry run with matching grant" };
+  }
+
+  const policy = input.grant?.policy.find((entry) => entry.action === input.action);
+  if (policy?.default === "deny") {
+    return { decision: "deny", riskScore, reason: `policy ${policy.id} denies ${input.action}` };
+  }
+  if (policy?.default === "approval_required") {
+    return { decision: "approval_required", riskScore, reason: `policy ${policy.id} requires approval` };
+  }
+  if (policy?.default === "allow_if_trusted_agent" && input.principal?.trusted) {
+    return { decision: "allow", riskScore, reason: `policy ${policy.id} allows trusted principal` };
+  }
+  if (policy?.default === "allow_if_below_risk_score") {
+    const maxRiskScore = typeof policy.conditions?.maxRiskScore === "number" ? policy.conditions.maxRiskScore : 0.25;
+    return riskScore <= maxRiskScore
+      ? { decision: "allow", riskScore, reason: `risk score is within policy ${policy.id}` }
+      : { decision: "approval_required", riskScore, reason: `risk score exceeds policy ${policy.id}` };
+  }
+
+  const band = riskBandForScore(riskScore);
+  if (band === "critical") {
+    return { decision: "deny", riskScore, reason: "critical risk requires admin override" };
+  }
+  if (isPolicyGatedPermission(input.action) || (WRITE_ACTIONS.has(input.action) && band !== "low")) {
+    return { decision: "approval_required", riskScore, reason: "default gate for risky account action" };
+  }
+
+  return { decision: "allow", riskScore, reason: "grant allows account action" };
+}