Phase 2: Lambda Container Migration Guide

Step to implement: $ARGUMENTS

Implementation Procedure

1. Read the detailed plan for the step in the references below
2. Verify that dependent steps are completed
3. Create/modify files specified in the deliverables
4. Write tests first (TDD) before implementing
5. Verify results according to validation criteria
6. Update step status in docs/progress.md

References

• Full migration plan with architecture and design: lambda-migration-plan.md
• OpenClaw analysis (internals, API surface, serverless blockers): openclaw-analysis.md
• Current architecture: architecture.md
• Cost constraints: cost-optimization.md
• Deployment procedures: deployment.md

Step Overview

Step	Title	Dependencies	Key Deliverables
2-1	Lambda Container Image + Handler	None	Dockerfile, handler.ts, session-sync.ts
2-2	CDK LambdaAgentStack	2-1	lambda-agent-stack.ts, ECR, IAM
2-3	Response Streaming Integration	2-1, 2-2	routeMessage update, WS push, Telegram
2-4	Session Lifecycle Management	2-1, 2-3	S3 lifecycle, locking, compaction
2-5	Fargate Deprecation + Cost Verification	2-1~2-4	Feature flag, docs, cost dashboard

Critical Constraints (Must Check Every Step)

• Zero OpenClaw code modifications — Wrapper layer only, upstream compatible
• Zero fixed costs — No resources that incur charges while idle
• No NAT Gateway — Lambda outside VPC (accesses S3 via public endpoint)
• No secrets on disk — API keys via env vars (SSM SecureString resolved at runtime)
• Backward compatible — Fargate path must remain functional as fallback
• Cost target — Total monthly cost < $1 at low usage (< 100 requests)

Key Technical Details

OpenClaw Library Import

// Use extensionAPI.js — avoids CLI/Gateway initialization
import { runEmbeddedPiAgent } from "openclaw/dist/extensionAPI.js";

Session File Path Convention

S3: s3://{bucket}/sessions/{userId}/{sessionId}.jsonl
Lambda /tmp: /tmp/.openclaw/agents/default/sessions/{sessionId}.jsonl

SessionManager Behavior

• SessionManager.open(path) → calls loadEntriesFromFile(path)
• File not found → returns empty array (no error)
• Uses sync fs: readFileSync, appendFileSync, writeFileSync
• All operations work on Lambda /tmp

Config Initialization

// HOME=/tmp → OpenClaw reads /tmp/.openclaw/openclaw.json
process.env.HOME = '/tmp';
// Minimal config (no gateway server needed)
{ "gateway": { "mode": "local" } }

Post-Validation Tasks

After implementation of each step:

1. Update step status in docs/progress.md
2. Check if docs/architecture.md needs updating
3. Run full test suite: npm run test && npm run test:e2e