Is OpenAI AgentKit free? What it actually costs in 2026
No free tier. It is a paid product.
There was no separate subscription — you paid ordinary API rates for what the agent consumed, roughly $1.75 per million input tokens and $14 per million output tokens on the flagship model, plus tool charges such as $0.03 per Code Interpreter session and $0.10 per gigabyte per day for file search. Enterprise agreements sat between roughly $2,000 and $20,000 a month. Figures checked 2026-07-30. The pricing was never the problem.
When paying is still the right call
Through November 2026, if what you have already works and rewriting it now costs more than running it out — there is no benefit in a panic migration for a system that will be replaced anyway. Stay too if you are prototyping this week and expect the result to be thrown away: managed tooling is genuinely faster for that, and a throwaway prototype has no migration cost by definition. And for the rest of OpenAI's API — models, ChatKit, the Responses API — nothing here is a reason to leave. Only the agent-building layer is closing.
What you are locked into
The prompts, the tool definitions and the model calls are portable — those are yours and they move. What does not move is the orchestration: a graph built in Agent Builder is a description held in OpenAI's product, not a file in your repository, and rebuilding it elsewhere means rebuilding the logic rather than exporting it. Evals histories are similar. This is the specific shape of visual-builder lock-in: the easier a platform makes it to avoid writing the wiring down, the less of the wiring you own when it leaves.
If you would rather not pay: LangGraph
LangGraph
Agents as an explicit state graph — the closest thing to what you are leaving.
Free and open source. LangGraph Platform is an optional paid hosted tier.
See all 4 OpenAI AgentKit alternatives comparedCompare the free options head-to-head
Pricing is verified against the vendor's published figures and dated above. Vendors change prices — confirm current numbers with OpenAI before you commit. More ai agent frameworks decisions on Macrostack.