Anthropic API
Programmatic access to Anthropic models for chat completion tool use and batch jobs with usage based pricing and enterprise controls across regions and clouds.
Overview
The Anthropic API gives developers direct access to Claude models for chat structured tool calls and long context processing. You send prompts with system and user messages, define tools to enable function calling, and stream outputs for responsive UIs. The platform supports large context windows for retrieval workflows, prompt caching to reduce cost on repeated headers, and a Batch API that discounts large offline jobs.
SDKs cover popular languages and you can deploy via Anthropic endpoints or through partner clouds with regional data controls. Pricing is usage based per million tokens by model, with entry pricing on smaller models suitable for prototypes and higher capability models for complex reasoning and coding. Teams adopt the API to power assistants analytics and agents while keeping observability security and abuse safeguards in place.
Key features
- Chat completion endpoints with tool use for function calling
- Large context windows for retrieval heavy prompts
- Prompt caching to cut cost on repeated system headers
- Batch API for discounted offline processing at scale
- Streaming responses for responsive front ends
- SDKs for Python JavaScript and partner cloud gateways
- Granular keys and project controls for teams
- Policies and safety tooling for responsible usage
Best for
- Build customer support copilots with reliable tool calling
- Create research assistants that summarize long documents
- Add coding helpers to IDE like environments
- Generate analytics narratives from dashboards and logs
- Process large archives via Batch for overnight runs
- Prototype assistants on small models then scale up
- Use prompt caching for workflows with stable headers
- Deploy in regions that meet privacy requirements
Capabilities
Tool Use Functions
Define tools in the schema and let the model request calls which your app executes to ground answers in real data.
Batch and Caching
Use discounted batch jobs and cache headers to cut cost for high volume long context workloads.
Realtime Output
Stream tokens for low latency experiences and better UX in chat apps and dashboards.
Projects and Policies
Manage keys quotas safety and regions while integrating with partner clouds when needed.
Frequently Asked Questions
How does pricing start?
Pricing is usage based per million tokens with smaller models around $0.25 input and $1.25 output per 1M tokens and larger models higher.
Is there a free tier?
Public API access is billed by usage, interactive apps like Claude have free and paid plans separate from API billing.
What about long context costs?
Long context and batch have separate modifiers, prompt caching reduces repeated header cost.
Can I use tools and function calling?
Yes, define tools for grounded actions and retrieval flows.
Do you support streaming?
Yes, streaming responses are available for chat like UIs.
Is there regional hosting?
Partner clouds offer regional endpoints and data controls.
How do I manage safety?
Use system prompts policies and abuse monitoring to meet risk requirements.
What languages are supported?
SDKs exist for Python JavaScript and more, any HTTPS client can call the API.
