What Does Codex Full Access Mean

Question

What does Codex full access mean, why is it warned about, and what boundary should apply in practice?

Full access means the agent may be able to read, write, and run commands across a much wider part of the local machine than the current project.

The warning exists because broader permissions increase the impact of mistakes.

Vipin’s rule for this repository is:

do not modify files outside the current project unless the user explicitly asks for it
if touching another project may help, confirm first before making changes

The issue is not that the agent will automatically start editing random files.

The issue is that once permissions are wider:

the reachable file scope is larger
a mistaken path or overly broad command can affect more than the intended project
installs, Git actions, and filesystem writes can have broader consequences

So the warning is about risk surface, not about a promise that the agent will misbehave.

In normal operation, the agent should still follow user intent and task scope.

Broader access should be used only to complete requested work more effectively, not to opportunistically edit unrelated files.

For vipin wiki, the durable rule is:

default write scope = current project or explicitly named repository
project-external edits require either:
- explicit user instruction, or
- confirmation first

This keeps broad local access from becoming broad editing authority.

broad access can still be useful for multi-repository work when the user clearly asks for it
the main remaining risk is ambiguous wording from the user, which is why cross-project changes should stay explicit