Best CLI APIs for Claude Code in 2026
These APIs work well when called directly from Claude Code via curl, SDKs, or scripts. They are ranked by how useful they are in a CLI-first workflow. Use an API when you need more control than an MCP server provides, or when no MCP server exists for the service.
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npm install octokitPayment processing - charges, subscriptions, invoices, and Connect.
npm install stripeWorkers, KV, R2, D1, DNS, and CDN management via REST.
npm install cloudflareComplete AWS access - S3, Lambda, DynamoDB, SQS, and 200+ services.
npm install @aws-sdk/client-s3GPT models, DALL-E, Whisper, embeddings, and assistants.
npm install openaiClaude models - chat, vision, tool use, and extended thinking.
npm install @anthropic-ai/sdkSMS, voice calls, WhatsApp, video, and phone number management.
npm install twilioPostgres, auth, storage, edge functions, and realtime subscriptions.
npm install @supabase/supabase-jsSearch-as-a-service - full-text search, faceting, and recommendations.
npm install algoliasearchFirebase auth, Firestore, storage, messaging, and remote config.
npm install firebase-adminServerless MySQL with branching, deploy requests, and schema management.
npm install @planetscale/databaseGmail, Calendar, Drive, Sheets, YouTube, Maps, and 200+ Google services.
npm install googleapisServerless Postgres over HTTP with connection pooling and branching.
npm install @neondatabase/serverlessEdge-hosted SQLite with sync, replication, and embedded replicas.
npm install @libsql/clientAuthentication, authorisation, user management, and SSO.
npm install auth0Document database - CRUD, aggregation pipeline, change streams, and Atlas.
npm install mongodbDeveloper-first email API with React Email support.
npm install resendEmail delivery - transactional, marketing, and template management.
npm install @sendgrid/mailTransactional email with industry-leading deliverability.
npm install postmarkEmail delivery, validation, and routing for developers.
npm install mailgun.jsVector database for embeddings, similarity search, and RAG.
npm install @pinecone-database/pineconeMessages, channels, users, files, and app interactions.
npm install @slack/web-apiDeployments, projects, domains, and serverless functions via REST.
npm install -g vercelDeploy and manage Fly.io apps, machines, volumes, and networking.
curl -L https://fly.io/install.sh | shOpen-source vector database with built-in vectorisation and hybrid search.
npm install weaviate-clientFull-text search, analytics, log aggregation, and APM.
npm install @elastic/elasticsearchBank connections, transactions, identity, and financial data.
npm install plaidCreate, read, and update Notion pages and databases via REST.
npm install @notionhq/clientGraphQL API for managing Linear issues, projects, cycles, and teams.
npm install @linear/sdkPayments, orders, inventory, customers, and point-of-sale.
npm install squareFrequently asked questions
When should I use an API instead of an MCP server?
Use an API when you need fine-grained control, custom error handling, batch operations, or features the MCP server does not cover. APIs are also better for scripting and automation pipelines.
Can Claude Code call APIs directly?
Yes. Claude Code can run curl commands, execute Node scripts with SDK calls, or use any CLI tool that wraps an API. You just need the right credentials set as environment variables.
How do I manage API keys in Claude Code?
Set API keys as environment variables in your shell profile or .env file. Never hardcode them in scripts. Claude Code can read environment variables when making API calls.