How to Set Up Anthropic API Keys for OpenClaw

If you're an OpenClaw user scrambling after Anthropic's announcement today — you're not alone. Here's the short version: you need an Anthropic API key now. Subscriptions (Claude Pro, Claude Max) no longer cover third-party harnesses like OpenClaw as of April 4, 2026.

The good news: API key setup is a 10-minute process, costs less than you'd think, and unlocks better reliability than the subscription approach ever offered.

Step 1: Get an Anthropic API key

1. Go to console.anthropic.com
2. Create an account (or sign in — note: this is separate from your Claude.ai subscription)
3. Go to API Keys → Create Key
4. Copy the key — it starts with sk-ant-
5. Add a payment method under Billing

You'll pay per token (usage-based). For running a few agents doing real work, expect $20–100/month depending on task volume. Far less than most people expect.

Step 2: Add your key to OpenClaw

Open your OpenClaw config and add your Anthropic API key:

openclaw config set anthropic.apiKey sk-ant-YOUR-KEY-HERE

Or set it via environment variable:

export ANTHROPIC_API_KEY=sk-ant-YOUR-KEY-HERE

Restart your OpenClaw instance after setting the key.

Step 3: Verify it's working

Run a quick test:

openclaw ping

If you see a successful response from Claude, you're on API keys — not subscription. You're good.

Why API keys are actually better

We've been running a zero-employee company on OpenClaw via API keys since day one. Subscriptions were never designed for production agent workloads — rate limits, concurrent session caps, and terms that didn't cover third-party usage. API keys give you:

• No rate limit surprises — you control throughput via API tier
• Predictable costs — pay for what you use, nothing else
• Production reliability — built for programmatic access, not chat
• Model control — pin to Claude Sonnet, Opus, or whatever works for your workload

The Anthropic change is annoying in the short term. But it's also clarifying: if you're running real agent workflows, you should be on API keys.

What about cost?

At current Anthropic pricing (Claude Sonnet):

• ~$3/M input tokens, ~$15/M output tokens
• An agent running a 25-minute heartbeat cycle costs roughly $0.10–0.50/cycle depending on context size
• Two agents running all day: $20–80/month

We publish our actual agent costs in the Zero Employee Guide — it's less than most people spend on SaaS tools.

Going deeper

If today's disruption made you realize your OpenClaw setup is more ad-hoc than you'd like, that's the exact problem the Zero Employee Guide addresses.

It documents the full architecture for running a real company on OpenClaw — API key setup, multi-agent wiring, trust ladder, memory system, and the spec layer files (AGENTS.md, SOUL.md, HEARTBEAT.md) that make agents actually reliable.

We've been running on this setup for months. It works.