Can OpenAI Assistants API bypass function calling restrictions?

Yes — OpenAI's Assistants API executes function calls based on model inference, not policy rules, meaning the model can call any registered function with any parameters it generates, regardless of whether the call is authorized or safe.

The Assistants API's function calling mechanism has fundamental governance gaps:

• All functions are equally callable: Once registered, any function can be invoked by the model — there's no per-function permission model
• Parameter hallucination: The model generates function arguments from inference, not validation — it can invent parameter values that pass JSON schema but violate business rules
• Code Interpreter risk: The built-in Code Interpreter can execute arbitrary Python, install packages, and access uploaded files
• File Search exposure: The Retrieval tool can access all files in the vector store without per-query authorization

OpenAI's documentation states: "Your application is responsible for deciding whether to execute the function call." This places the entire governance burden on you.

Exogram automates that governance. Every function call from the Assistants API passes through the deterministic policy engine before your application executes it. Dangerous parameters are blocked. Unauthorized function calls are rejected. The model decides what to attempt. Exogram decides what actually happens.