Memory boundaries

Parent and child memory are separate by default. agent.asTool(...) runs the child as a stateless prompt and does not create or reuse a child session.

Prefer stateless specialists

Most specialist tasks should receive everything they need in the tool prompt:

Review this draft for policy risk.

Customer tier: Enterprise
Region: EU
Draft: ...

Stateless children are easier to test, retry, trace, and reason about. They cannot silently depend on facts from an earlier delegation.

Add child memory explicitly

When a child truly needs continuity, create a normal tool whose handler calls the child through .session(...):

import { createTool } from '@anvia/core'
import { z } from 'zod'

function createPolicyMemoryTool(input: {
  policyAgent: typeof policyAgent
  threadId: string
  user: User
}) {
  return createTool({
    name: 'ask_policy_memory',
    description: 'Ask the policy agent using its scoped session history.',
    input: z.object({
      prompt: z.string().min(1),
    }),
    output: z.string(),
    async execute({ prompt }) {
      const session = input.policyAgent.session(
        `policy:${input.threadId}`,
        {
          userId: input.user.id,
          metadata: { tenantId: input.user.tenantId },
        },
      )

      const response = await session
        .prompt(prompt)
        .maxTurns(2)
        .send()

      return response.output
    },
  })
}

The application—not the coordinator model—owns the child session ID and user or tenant scope.

Choose the memory owner

State	Owner
User conversation and final replies	Coordinator session
One-off specialist task	Child prompt, no memory
Durable specialist workflow	Explicit child session
Live product state	Scoped service or tool
Parent-child runtime events	Observability backend

Do not use memory as the source of truth for permissions or current product state.

Avoid accidental sharing

Never reuse one child session ID across unrelated users, tenants, or parent conversations. Include stable product-owned scope and configure the memory store to enforce it.

Do not copy the full parent transcript into every child session. Pass only the task and evidence the specialist needs; otherwise the specialist boundary provides little isolation and consumes unnecessary context.

Know the tradeoff

Durable child memory adds storage, retention, compaction, privacy, and retry concerns. Add it only when a specialist must continue its own conversation across calls—not merely because the parent already has memory.