Tag: openai-sdk

Every agent request pays for its system prompt, the provider's hidden tool-use preamble, and every tool schema before the user says anything. How to measure that fixed cost with differential count_tokens calls on the Anthropic API, the input_tokens endpoint on OpenAI, an MCP listTools probe, and /context in Claude Code, anchored to claude-opus-5-5, claude-sonnet-5, and @modelcontextprotocol/client 2.1.0.

Conversation history can live in your process, in your database, in the provider, or on the machine that ran the agent. Where you put it does not change your token bill, it decides your retention exposure, and it decides whether you can ever change providers. The numbers, the retention windows, and a storage shape that survives all three.

A step-by-step checklist for moving a .NET app off the raw OpenAI 2.12 SDK onto the provider-neutral Microsoft.Extensions.AI 10.7 IChatClient. Covers the AsIChatClient bridge, the CompleteChatAsync-to-GetResponseAsync rewrite, streaming, tool calling, DI registration, and the gotchas that bite mid-cutover.

Claude subagents give you orchestration-level parallelism out of the box: one agent spawns isolated sub-contexts that run concurrently. OpenAI Assistants never had that, and it shuts down August 26, 2026, so new parallel work belongs on the Responses API plus your own fan-out. Here is how the two models actually differ and which to reach for.

Wire AIFunctionFactory.Create, ChatOptions.Tools, and ChatClientBuilder.UseFunctionInvocation in Microsoft.Extensions.AI 10.5 so an IChatClient can call your .NET methods automatically. Covers OpenAI and Azure OpenAI providers, the FunctionInvokingChatClient knobs that actually matter (iteration limits, concurrent calls, approval prompts, error handling), and streaming responses with tools.