Plan with approval

Generate a plan, pause for human review, execute on approval. Plan + flow + signal.

This recipe builds a workflow that proposes a plan, suspends for human review, and resumes only after a user approves (or modifies) it. The plan persists in CruxStore so the UI can render it live; the flow suspends so server resources don't sit idle.

Primitives used

plan() from @crux/core/plan for the persistent plan document
flow() from @crux/core/flow with flow.suspend() for the approval pause
signalFlow() (or handle.signal()) to resume once the user clicks Approve
usePlan() from @crux/react for live UI subscription

When to reach for this pattern

The agent's plan needs human approval before consequential action
The wait between plan and approval may be minutes to days
You want server resources released during the wait — no spinning

Full code

Backend

import { plan, updatePlan } from '@crux/core/plan'
import { flow } from '@crux/core/flow'
import { generate } from '@crux/ai'
import { openai } from '@ai-sdk/openai'
import { z } from 'zod'

const writerFlow = flow('writer-flow', async (flow) => {
  // Step 1: produce a plan via LLM
  const planContent = await flow.step('draft-plan', async () => {
    const result = await generate(planPrompt, {
      model: openai('gpt-4o'),
      input: { brief: flow.input.brief },
    })
    return result.text
  })

  // Step 2: persist the plan
  const planHandle = await flow.step('persist-plan', async () => {
    const p = await plan({
      title: flow.input.title,
      content: planContent,
      metadata: { status: 'draft', flowId: flow.flowId },
    })
    return { planId: p.id }
  })

  // Step 3: suspend until approval
  const approval = await flow.suspend('await-approval', {
    schema: z.object({ approved: z.boolean(), revisions: z.string().optional() }),
    timeout: '7d',
  })

  if (!approval.approved) {
    return { status: 'rejected', planId: planHandle.planId }
  }

  // Step 4: execute the plan
  return flow.step('execute', async () => {
    return generate(executePrompt, {
      model: openai('gpt-4o'),
      input: { plan: planContent, revisions: approval.revisions },
    })
  })
})

Approval mutation

import { signalFlow } from '@crux/core/flow'
import { updatePlan } from '@crux/core/plan'

export async function approvePlan(planId: string, flowId: string, revisions?: string) {
  await updatePlan(planId, { metadata: { status: 'approved' } })
  await signalFlow(flowId, 'await-approval', { approved: true, revisions })
}

export async function rejectPlan(planId: string, flowId: string) {
  await updatePlan(planId, { metadata: { status: 'rejected' } })
  await signalFlow(flowId, 'await-approval', { approved: false })
}

Live UI

'use client'
import { usePlan } from '@crux/react'

export function PlanReview({ planId, flowId }: { planId: string; flowId: string }) {
  const plan = usePlan(planId)
  if (!plan) return <p>Loading...</p>

  return (
    <article>
      <h1>{plan.title}</h1>
      <pre>{plan.content}</pre>
      <p>Status: {String(plan.metadata?.status)}</p>
      <button onClick={() => approvePlan(planId, flowId)}>Approve</button>
      <button onClick={() => rejectPlan(planId, flowId)}>Reject</button>
    </article>
  )
}

How it works

The flow drafts the plan and persists it. The plan document lives in CruxStore; the UI subscribes via usePlan() and re-renders when the content changes.
flow.suspend('await-approval', { schema, timeout }) releases the server. The flow's state is checkpointed; nothing runs until a signal arrives. The schema validates the signal payload on resume.
The mutation signals the flow. signalFlow(flowId, name, payload) writes to the store; on Convex, schedule the resume action from an app-local signal helper.
The flow resumes from after suspend(). Earlier flow.step() results are cached — only the post-suspend work re-runs.

Variations

Allow plan revisions

If the user can edit the plan instead of approving as-is, signal with the revised content. The execute step receives it via the validated approval.revisions field.

Multiple approvers

Use a different signal name per role ('await-finance', 'await-legal') and chain suspends. Each must signal in turn.

Plans on Convex

Use flow() from @crux/convex/server so the flow handle exposes .action, .handler, .args, and .signal() for Convex-aware start/resume.