Browser tools
Create, preview, and structurally validate selected files locally. The site does not apply a theme to Codex.
LOCAL RUNTIME SAFETY
Safety and Local Runtime Boundaries
Know which layer handles the files, what Structural PASS does not prove, and when to stop before or during local Engine use.
Local Engine
An independent process uses a loopback CDP endpoint. Keep the endpoint on a trusted local machine.
Stop and restore
Stop for FAIL, CANNOT_VERIFY, mismatched hashes, unexpected files, platform mismatch, or incomplete recovery.
What the website does
CodexSkin Tools creates, previews, and structurally validates Enhanced theme files in the browser. Selected image and theme JSON files are not uploaded under the current True MVP contract. The website does not directly control Codex and does not execute user-provided packages.
What the local Engine does
Applying an Enhanced theme requires the independent Codex Dream Skin local Engine. The Engine launches or connects to Codex through a loopback Chrome DevTools Protocol endpoint and injects CSS or DOM into the local renderer. The loopback debug endpoint does not provide user-level authentication. Use it only on a trusted local machine and close the themed session through Restore when finished.
Before applying
Save work and close or back up important sessions. Use only a named theme directory containing one theme JSON and one referenced PNG, JPEG, or WebP image. Review the theme source, hashes, Runtime status, and exact platform and build evidence. Do not apply files that FAIL validation or contain scripts, executable content, nested archives, path traversal, or unexpected files.
What validation means
PASS means known structural checks passed. It does not establish runtime compatibility, absence of malicious behavior, system safety, certification, or OpenAI support. Missing parser, metadata, hashing, counterpart file, or target-build evidence must produce CANNOT_VERIFY or NOT_VERIFIED. WARN requires review, and FAIL identifies a blocking structural result.
Apply and Restore
Follow the platform-specific Apply, Verify, and Restore guide for the pinned Runtime SHA. A restore claim requires evidence that injected content was removed, the themed CDP session and port were closed, and stock Codex reopened without debug flags. If the current Codex build differs from the tested build, show REVERIFY_REQUIRED or NOT_VERIFIED.
Read the evidence record
Runtime evidence is limited to the exact OS and architecture, Codex build, Engine version, Runtime SHA, artifact hash, date, evidence hash, and recovery record shown. REFERENCE_ONLY is not a CodexSkin formal verification. SHA-256 values support integrity comparison; they are not digital signatures, identity proof, malware review, or safety certification.
Stop conditions and recovery
Stop when validation FAILS, a required check returns CANNOT_VERIFY, rights or redistribution is blocked, a hash differs, package contents are unexpected, or the platform guide does not match. During Restore, keep checking until the injected content, themed process, debug port, and stock reopen are all accounted for. Do not turn an incomplete check into a positive state.
Independent status
CodexSkin Tools is an independent project and is not affiliated with, endorsed by, or sponsored by OpenAI.
Keep the loopback session contained
Treat the themed session as a temporary local operation. Confirm that the Engine guidance names the intended loopback address and pinned Runtime SHA before starting. Do not forward, proxy, or expose the debug port to another device or network. Keep unrelated browser and Codex sessions separate so the user can identify which process belongs to the themed run. When the task is finished, use the documented Restore flow and check the process and port instead of assuming that closing a visible window ended the local session.
Interpret incomplete checks
An unavailable check is information, not a neutral pass. If image metadata cannot be decoded, a counterpart file is missing, hashing cannot run, or the target build has no evidence, keep CANNOT_VERIFY or NOT_VERIFIED next to the affected item. Explain what input or capability is missing and what the user can provide or review next. Do not average completed checks into a score that hides a blocking FAIL or an unavailable security-relevant check.
Preserve a recovery record
A useful recovery record identifies the same operating system, architecture, Codex build, Engine version, Runtime SHA, and artifact that were used for Apply. It records removal of injected content, closure of the themed CDP session and loopback port, and reopening of stock Codex without debug flags. If the user can confirm only part of that sequence, show the completed observations and label the remaining recovery result CANNOT_VERIFY. This keeps a partial observation from becoming a general restore claim.
States
preflight
Before applying: save work, validate files, review source, rights, hashes, exact evidence, and Restore.
runtime_default
Runtime status: NOT_VERIFIED unless complete exact-build evidence is displayed.
stop
Stop for FAIL, CANNOT_VERIFY, mismatched hashes, unexpected files, blocked rights, or a platform mismatch.
Errors
validation_block
The supplied files did not clear structural review. Do not continue to local Engine use.
recovery_gap
Recovery evidence is incomplete. Do not state that stock Codex has been restored.
Frequently asked questions
Does Structural PASS establish that a theme is safe to run?
No. PASS reports known structural checks only; it does not establish runtime behavior, absence of malicious behavior, system safety, certification, or platform support.
Why does the local Engine use a loopback endpoint?
The independent Engine launches or connects to Codex through a local Chrome DevTools Protocol endpoint to inject CSS or DOM into the local renderer. The endpoint lacks user-level authentication and should remain on a trusted local machine.
What evidence is required before saying Restore completed?
The record must show that injected content was removed, the themed CDP session and port were closed, and stock Codex reopened without debug flags.