Perplexity announced that its traditional Sonar Chat Completions API would move to the Agent API, with the retirement of the legacy endpoint scheduled for September 27, 2026. The announcement appeared in Perplexity's official API forum on August 13, and a team representative reiterated the planned retirement on September 10. As of the information in these reports, the actual shutdown of the endpoint has not been independently verified.
What Perplexity announced
Perplexity is directing developers from the traditional Sonar API workflow toward its Agent API. The Agent API is described as combining web search, multi-step research, code execution and access to multiple models within a broader agent-oriented interface.
The change is more than a simple endpoint rename: developers should review how their current integration calls the API, handles responses and manages tools before migrating. The official announcement and follow-up establish the planned transition, but they do not confirm that every legacy request stopped working on the scheduled date.
Key dates and status
- August 13, 2026: Perplexity published the announcement “Sonar is moving to the Agent API” in its official community forum. The reported time was 21:43; the time zone was not specified.
- September 10, 2026: a Perplexity representative confirmed the planned retirement of the Sonar Chat Completions endpoint.
- September 27, 2026: the scheduled retirement date for the legacy endpoint.
- Current verification status: the reports confirm the announced schedule, but do not establish whether the endpoint was actually disabled.
Because the planned retirement date has passed, developers should test their existing integration and consult the latest official API documentation or support channel rather than assume either continued availability or a completed shutdown.
What the Agent API brings together
Perplexity describes the Agent API as providing several capabilities in one API workflow:
- Web search: retrieve information from the web as part of an API-driven workflow.
- Multi-step research: support research that requires multiple stages rather than a single prompt-and-response exchange.
- Code execution: run code as part of supported agent workflows.
- Multiple models: access different models through the Agent API.
These capabilities may change how an integration is designed, particularly when a product currently relies on a single Sonar Chat Completions request. Developers should confirm exact model availability, tool behaviour, response formats and pricing in the current documentation before migrating.
What developers should check before migrating
- Identify legacy calls. Search application code, environment configuration and deployment settings for the Sonar Chat Completions endpoint.
- Review the Agent API documentation. Map the existing request and response fields to the new API's supported interface instead of assuming a drop-in replacement.
- Test retrieval and citations. If your product depends on web results, verify the format, source handling and behaviour expected by your application.
- Check tool permissions. If using code execution or other agent tools, ensure they are explicitly configured and appropriate for the workload.
- Validate error handling. Test timeouts, retries, rate limits and failures before deploying the new integration.
- Monitor cost and latency. Multi-step research and tool use can differ from a single chat-completion call. Measure actual usage rather than assuming equivalent performance or cost.
- Confirm endpoint status. Since the announced retirement date has passed, test safely and verify status with Perplexity's current official guidance.
What this means for AI Search integrations
For teams building search, research or answer-generation products, the move signals a shift toward a more tool-oriented API workflow. Instead of treating web retrieval as a single model response, an agent API can coordinate search and other supported tools as part of a larger task.
That does not mean every Sonar integration needs the same migration design. A lightweight search-answer workflow may require a different setup from a multi-step research assistant. Teams should map the capabilities they actually use, migrate only the necessary workflow, and test output quality against representative queries.
What is confirmed—and what remains unverified?
- Officially announced: Perplexity said Sonar was moving to the Agent API.
- Schedule reported: the legacy Sonar Chat Completions endpoint was planned for retirement on September 27, 2026.
- Team follow-up: a Perplexity representative reiterated the retirement plan on September 10.
- Agent API capabilities described: web search, multi-step research, code execution and access to multiple models.
- Not verified in the cited reports: whether the legacy endpoint was actually disabled on September 27.
Frequently asked questions
When was the Sonar Chat Completions endpoint scheduled to retire?
Perplexity's announced date was September 27, 2026, following the August 13 announcement and a September 10 confirmation from a team representative.
Has the endpoint definitely been shut down?
The cited forum posts establish the announced retirement schedule, but they do not verify the actual shutdown. Developers should check current official guidance and test their integration.
What does the Agent API provide?
Perplexity describes it as combining web search, multi-step research, code execution and access to multiple models.
Can the Agent API replace Sonar with no code changes?
Do not assume it is a drop-in replacement. Review the current API documentation and test request formats, response handling, citations, tools, errors and usage costs.
What should teams do now that the retirement date has passed?
Audit legacy endpoint calls, test the existing integration safely, review the Agent API migration guidance and confirm the current endpoint status with Perplexity.
The takeaway
Perplexity announced a transition from traditional Sonar Chat Completions to the Agent API, with September 27, 2026 set as the legacy endpoint's retirement date. The Agent API brings together web search, multi-step research, code execution and multiple models. The cited announcements confirm the plan, not the endpoint's actual shutdown, so developers should verify current status and test their migration rather than rely on the date alone.
Primary sources
Perplexity API Platform Forum — Sonar is moving to the Agent API; Perplexity API Platform Forum — Sonar moving to Agents API.