GROWTH PATTERN

Adding Activation to FastAPI + LangChain + PostgreSQL Apps

FastAPI + LangChain + PostgreSQL creates user sessions, but doesn't connect authentication events to growth automation workflows.

FastAPI + LangChain + PostgreSQL

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What's Missing in Standard FastAPI + LangChain + PostgreSQL Architecture

Without an infrastructure layer listening to PostgreSQL events, you rely on manual cron jobs or messy webhooks to track when users reach their first value milestone. Most setups require custom code to detect activation.

Standard FastAPI + LangChain + PostgreSQL Flow vs Optimized Skene Flow

Standard Flow
1

User signs up via authentication

2

User record created in PostgreSQL

3

No automatic trigger - manual follow-up required

Skene Flow
1

Watch PostgreSQL 'users' table for new signups using CREATE TRIGGER

2

Detect when user completes first key action (e.g., creating their first project) using PostgreSQL queries

3

Trigger activation email sequence via Resend with personalized onboarding

4

Track activation completion and send milestone emails

Visual comparison of the flows:

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How Skene Fixes This

This Skene Prompt installs activation detection into FastAPI + LangChain + PostgreSQL by watching PostgreSQL tables for key user actions. When users complete their first value milestone like creating their first project, it triggers welcome sequences and feature discovery emails.

Implementation Comparison

Using Skene Infrastructure

Install via Prompt

cursor.mdc
@task: Initialize Skene.
@action: Analyze my local code, validating subscription via `npx skene login`, and generate `skene.config.ts` to implement the Activation Loop pattern for FastAPI + LangChain + PostgreSQL.

Copy Skene Prompt for Cursor

Generated skene.config.ts

skene.config.ts
// skene.config.ts - The Automated Way
import { defineLoop } from '@skene/sdk';

export default defineLoop({
  type: 'activation',
  opinion: 'Detect when users complete their first key action and trigger personalized onboarding',
  steps: [
    {
      trigger: {
        type: 'database',
        table: 'users',
        event: 'insert'
      },
      condition: {
        type: 'query',
        query: `SELECT * FROM user_actions WHERE user_id = $1 AND action_type = 'first_project_created'`,
        timeout: '5m'
      },
      action: {
        type: 'email',
        provider: 'resend',
        template: 'activation_welcome',
        personalization: {
          name: '{{user.name}}',
          activationLink: '{{user.activation_link}}'
        }
      }
    }
  ],
  recovery: {
    retries: 3,
    backoff: 'exponential'
  }
});

Frequently asked questions