Perplexity's own model steps aside: the Sonar API becomes a shop selling OpenAI, Anthropic and Google

Perplexity's developer documentation now opens with a line that reads like a quiet change of business: "Sonar Chat Completions is now Agent API." The interface the company launched on 21 January 2025 to sell its own search-grounded model is being succeeded by one built around an agent loop — and around other companies' models. The Agent API is described as a unified interface for agent applications, with built-in tools the old endpoint never had: web search, URL fetching, code sandboxes, MCP servers, people search and finance search. Instead of a `messages` array with `choices`, a request produces a typed `output` array recording each step the agent took — reason, act, observe, continue, all inside a single call. The more interesting detail is the model list. Alongside Sonar, the Agent API brokers model families from OpenAI, Anthropic, Google, xAI, Z.AI, Moonshot AI and NVIDIA. A platform that existed to sell one proprietary answering model is now largely a way to buy everyone else's, with Perplexity's search stack as the wrapper. Sonar itself has not been switched off. The documentation says Sonar Chat Completions remains supported, while calling the Agent API more performant and cost-effective for production workloads — the standard phrasing of a migration that has not yet been given a deadline. Sonar Pro pricing is unchanged at 3 USD per million input tokens and 15 USD per million output, plus 6-14 USD per 1,000 requests depending on how much searching the answer required. The strategic reading is straightforward. Sonar's advantage was never raw reasoning; it was reading the live web and citing it, which is why it leads factuality benchmarks like SimpleQA while trailing frontier models elsewhere. Wrapping that retrieval layer around whichever model a developer prefers is a better use of the asset than asking them to accept Perplexity's model as well.