Anthropic Ships Claude 4 Sonnet with Extended Context and Native Browser Tool-Use for Enterprise Agents

## What Changed in Claude 4 Sonnet Anthropic's Claude 4 Sonnet release brings three headline capabilities to enterprise deployments: a 400,000-token context window, a native browser tool that agents can invoke directly within the API, and improved instruction-following on multi-step agentic tasks that span hours rather than minutes. The extended context window allows a single agent call to ingest entire legal contracts, codebases, or product catalogues -- eliminating the chunking pipelines that have added latency and complexity to enterprise retrieval-augmented-generation stacks. Early testers in the financial services sector report that audit workflows previously requiring five sequential API calls now complete in one. ## Browser Tool-Use in Practice The native browser capability is the more disruptive addition for agentic commerce. Rather than relying on third-party browser-automation layers, agents can request a browser session directly from the Claude API, navigate to a URL, interact with dynamic elements, and return structured results. For classifieds and marketplace platforms, this means agents can verify listing prices on competing platforms, check seller profile pages, confirm inventory availability, and compile cross-platform deal summaries -- all within a single agent loop. ## Pricing and Availability Claude 4 Sonnet is available through Anthropic's API at $3 per million input tokens and $15 per million output tokens, with a Batch API option at 50% discount for non-latency-sensitive workloads. Enterprise tier customers receive priority capacity and dedicated rate limits.