Perplexity
The Perplexity provider uses provider key perplexity and the HPD-Agent.Providers.Perplexity package. It is backed by HPD's shared OpenAI-compatible chat-completions client, so ModelName is a Perplexity chat model id.
Set an API key:
export PERPLEXITY_API_KEY="..."The default endpoint is https://api.perplexity.ai/, which sends chat requests to chat/completions. Pass endpoint to WithPerplexity(...), set Endpoint in ClientProviderConfig, or use PERPLEXITY_ENDPOINT / PERPLEXITY_BASE_URL when you need a compatible proxy or custom base URL.
Use fluent chat setup first:
using HPD.Agent;
using HPD.Agent.Providers.Perplexity;
var agent = await new AgentBuilder()
.WithPerplexity(model: "sonar-pro")
.BuildAsync();
var result = await agent.RunAsync("Write one sentence about Perplexity setup.");
Console.WriteLine(result.Text);The equivalent Clients.Chat shape is:
{
"Clients": {
"Chat": {
"ProviderKey": "perplexity",
"ModelName": "sonar-pro"
}
}
}Runtime Chat Options
Use ChatRunConfig for shared model-call behavior such as temperature, top-p, max output tokens, stop sequences, response format, tools, tool mode, seed, and generic reasoning options. Put agent-level defaults in ClientProviderConfig.ChatDefaults or .WithChatDefaults(...); use AgentRunConfig.Chat for per-run or per-session overrides.
Caveats
Perplexity responses may include citations and search-grounding metadata. The shared OpenAI-compatible client maps OpenAI-style annotations, top-level citations, and search_results into MEAI CitationAnnotation entries when those fields are present.
This provider currently registers the chat family only. Other endpoint families, if the upstream service exposes them, are deferred until HPD has dedicated provider-family support for that surface.
Chat uses HPD's shared OpenAI-compatible chat-completions client. It supports token streaming, function tools, response format and tool mode, multiple tool calls, MEAI image content parts, reasoning effort/content, seed, max output tokens, top-p, temperature, and stop sequences where the selected model supports them.
Validation checks model and endpoint configuration. Runtime chat options are applied through ChatDefaults and AgentRunConfig.Chat. Missing credentials fail at BuildAsync() before a live provider call.