// GLOSSARY -- WEB3 INFRASTRUCTURE

What is API Key?

1 min read Updated

An API key is a unique identifier used to authenticate requests to an API service — controlling access, tracking usage, and enforcing rate limits for applications interacting with blockchain infrastructure.

WHY IT MATTERS

API keys are the access credentials for blockchain infrastructure. RPC providers (Alchemy, Infura), data providers (CoinGecko, Etherscan), and DeFi APIs all require API keys to authenticate requests and manage quotas.

Key management best practices: never expose keys in frontend code (use server-side proxying), rotate keys regularly, use different keys for development/production, and set appropriate rate limits per key.

For AI agents, API key management is a security consideration — agents need access to blockchain APIs but keys should be scoped and limited to prevent misuse if the agent is compromised.

FREQUENTLY ASKED QUESTIONS

Is it safe to put API keys in code?
Never in frontend/client-side code (anyone can see them). Server-side environment variables or secret management services (Vault, AWS Secrets Manager) are standard. Never commit keys to Git.
What happens if my API key is leaked?
Rotate immediately. Attackers can use your quota, potentially incurring costs or gaining access to your application's data. Most providers support instant key rotation.
How do rate limits work?
Providers cap requests per second/day per API key. Exceeding limits returns errors (429 Too Many Requests). Paid plans offer higher limits. Design applications with retry logic and caching.

FURTHER READING

Enforce policies on every tool call

Intercept is the open-source MCP proxy that enforces YAML policies on AI agent tool calls. No code changes needed.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
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