Anthropic API
The Anthropic API is a developer interface for sending inputs to Claude models and receiving generated responses. The skill involves translating application requirements into supported message formats, tool interactions and streaming behavior, then handling authentication, usage, errors and model-specific capabilities as part of a reliable service integration.
What it is
An application submits a request containing a model identifier, input messages and supported configuration. Responses may include text, tool requests or other content blocks, depending on the model and endpoint. When a tool is requested, application code decides whether and how to execute it and returns the result for a subsequent model step. Streaming delivers events incrementally rather than a single completed response. API access is distinct from using the Claude chat product: the developer owns application state, authorization, retry behavior and the user experience around the model.
What the work involves
Implementation starts with the current endpoint and SDK documentation. The practitioner stores credentials securely, validates message construction, sets explicit time and output limits, and records request identifiers and usage without indiscriminately logging sensitive inputs. Tool handlers enforce their own permissions and validate arguments. Integration tests cover interrupted streams, rate limits, partial results and refusal or unsupported-content cases. A versioned client adapter and a small evaluation set make it possible to assess a model migration before routing normal traffic to it.
Illustrative example
A document assistant sends a report and asks Claude to extract a constrained set of issues. When the model requests a lookup tool, the application checks that the referenced document belongs to the current user, retrieves the allowed passage and returns it as a tool result. The interface shows partial text as streaming events arrive and records completion separately from connection success. An interrupted response is retried according to an explicit policy instead of being presented as a finished review.
Limits and common mistakes
API features, limits and model availability change, and a feature supported by one model may be absent from another. A successful HTTP response does not establish valid content or correct tool behavior. Retries can duplicate application-side actions unless handlers are designed for that possibility. Vendor documentation establishes the interface, while representative task evaluations establish whether a particular Claude configuration is suitable for the application's needs.
Prerequisites
Related skills
- → is an instance of: LLM API Integration
Sources and further reading
- Claude API overview
Official entry point for API authentication, endpoints, SDKs and request conventions.
Last updated: 2026-10-10