Plugin skill name validation rejects skills with qualified name > 64 chars

I'd like to work on this. I've traced the root cause and have a targeted fix in mind.

The current MAX_NAME_LEN = 64 in codex-rs/core-skills/src/loader.rs is shared across both standalone skill names and plugin-qualified names (namespace:skill_name). The validation in validate_len applies the same limit regardless of whether the name includes a namespace prefix, so compound names like build-web-data-visualization:grammar-of-graphics-and-declarative-visualization (78 chars) are rejected even though the individual parts are reasonable lengths.

A clean fix is to introduce a separate MAX_QUALIFIED_SKILL_NAME_LEN = 128 constant for plugin-namespaced names, while keeping MAX_NAME_LEN = 64 for standalone skill names and unrelated metadata fields — avoiding the concern of accidentally widening limits that should stay narrow.

I'll share a full root-cause analysis and diff shortly. Happy to submit a PR if the team would like me to implement this.

Root cause & fix

After tracing the code, here's the detailed analysis:

Root cause

In codex-rs/core-skills/src/loader.rs, MAX_NAME_LEN = 64 is shared between standalone skill names and plugin-qualified names. In parse_skill_file, the name field is validated with validate_len(&name, MAX_NAME_LEN, "name") — but by the time validation runs, the name has already been qualified into plugin_name:skill_name format by namespaced_skill_name(). This means the full combined string is measured against a 64-char limit intended for simple names.

Fix

Introduce a separate MAX_QUALIFIED_SKILL_NAME_LEN: usize = 128 constant, and use it conditionally when the name contains : (indicating a plugin-namespaced form):

 const MAX_NAME_LEN: usize = 64;
+const MAX_QUALIFIED_SKILL_NAME_LEN: usize = 128;

 // in parse_skill_file, name validation:
-validate_len(&name, MAX_NAME_LEN, "name")?;
+validate_len(
+    &name,
+    if name.contains(':') {
+        MAX_QUALIFIED_SKILL_NAME_LEN
+    } else {
+        MAX_NAME_LEN
+    },
+    "name",
+)?;

This keeps MAX_NAME_LEN = 64 for all other fields (MAX_DEPENDENCY_TYPE_LEN, MAX_DEPENDENCY_TRANSPORT_LEN, display names, etc.) — no unintended widening of unrelated limits.

With this fix, all 8 skills in build-web-data-visualization (qualified names up to 78 chars) would load successfully.

My fork branch with the implementation: fix/24950-qualified-skill-name-len

Happy to submit a PR if the team would like me to implement this.

Reproduced again on 2026-07-28 with a newer Codex Desktop and curated-plugin revision.

Environment

• Windows 11 Pro x64 (10.0.26200)
• Codex App 26.721.4979.0
• build-web-data-visualization plugin 0.1.21
• OpenAI-managed cache revision 11c74d6b
• Codex App Server skills/list, queried with forceReload=false

Current result

• The RPC completes successfully, but the semantic result contains only 10 loaded skills from this plugin and 8 validation errors.
• All 8 errors are still: invalid name: exceeds maximum length of 64 characters.
• They affect the same 8 skill directories listed in the issue body.
• The current plugin contains 18 SKILL.md files. The longest raw name is 49 characters, while the 8 rejected qualified names are 67–78 characters.
• The cache path was redacted, but it is the standard %USERPROFILE%\.codex\plugins\cache\openai-curated\build-web-data-visualization\11c74d6b\... location.

This is notable because #25782 was merged on June 2 and included in 0.137.0 on June 4. The current Codex App Server behavior still matches the pre-fix validation of the full plugin:skill name against the 64-character base-name limit.

Could you confirm whether Codex App 26.721.4979.0 contains #25782 and whether the App Server skills/list path uses the same fixed loader? This may be a Desktop packaging/runtime regression or a loader path not covered by the original fix.