How to create a Claude API key and set a spend limit

In short: create the key in the Claude Console, then set a monthly spend limit on the Billing page. With Claude, an agent that answers about health, legal or financial matters needs qualified human review, and voice messages go to a person on your team.

Create the key

1. Go to the Claude Console at platform.claude.com and sign in, or create an account. The Console is where the API is billed; it is not the Claude chat app.
2. Open the API keys page (platform.claude.com/settings/keys).
3. Select Create key, name the key, select an expiration and set Linked account to yourself or to a service account. A personal key stops working if you leave the organization, so use a service account key for anything shared.
4. The Console shows the full key, which starts with sk-ant-, only once. Copy it and keep it in a safe place, such as a password manager. If you lose it, create a new key.
5. If Create key is disabled, your role does not allow it: ask an organization admin to change your role or to create a service account key.

Set a spend limit

1. In the Console, open the Billing page (platform.claude.com/settings/billing).
2. In the Spend limits section, select Adjust limit, or Set limit if none is set yet.
3. Enter the new value. Your limit cannot be above the cap of your usage tier. When usage reaches a limit you set, the API refuses requests until you raise the limit or the month ends.
4. Optional: create a workspace for ZapClaw and set a spend limit on that workspace, so this one use cannot spend more than you chose. The default workspace cannot take a spend limit.

Good to know about Claude

• Human review: Anthropic's usage policy asks for qualified human review in high-risk areas: health, legal, finance, insurance, employment and housing. If your agent answers in one of them, a qualified person on your team must review what it says, and the agent should hand those cases over.
• Voice messages: Claude does not transcribe audio and ZapClaw has no transcriber of its own, so on Claude a voice message is not transcribed. It goes to a person on your team. Gemini and OpenAI keys transcribe voice messages.
• AI notice: Anthropic's policy asks a chatbot that talks to consumers to say it is an AI. ZapClaw opens every conversation with a short AI notice, and the agent never claims to be a person.

Then add the key to ZapClaw

In the ZapClaw dashboard, open the AI key screen of ZapClaw Agents and paste the key there. ZapClaw stores it encrypted. If the provider refuses a request because the key is invalid, out of credit or over its limit, ZapClaw tells the person in charge and the conversation goes to your team. Each provider has its own guide: OpenAI, Gemini and Anthropic.

Steps taken from Anthropic's own help: get your Claude API key and rate limits and spend limits.

Provider consoles change their labels from time to time. If a button reads differently, follow the provider page linked above.