`PluginConfigValidator` can never run: `PluginLoader` calls its own `validatePluginConfig(metadata)` with no config, and a plugin factory closes over its config so the kernel never receives it

[os-zhuang]

Found while implementing #11637 (the REST server config seam). Filed, not fixed — #11637's declared surface is packages/rest/src/rest-server.ts, and this is a packages/core mechanism with its own gate family.

#11637 offered "declare configSchema on the REST plugin and let the kernel's plugin-config-validator do it" as one of its two candidate fixes. Measuring that candidate is what turned this up: the mechanism cannot run at all, for any plugin, so the candidate was structurally unavailable and #11637 landed the seam-side parse instead.

What was measured

On origin/main @ 7899f5745.

1. The one call site passes no config. packages/core/src/plugin-loader.ts:157-159:

if (metadata.configSchema) {
 this.validatePluginConfig(metadata); // <- no second argument
}

and :406-419:

private validatePluginConfig(plugin: PluginMetadata, config?: any): void {
 if (!plugin.configSchema) return;
 if (config === undefined) {
 // In loadPlugin, we often don't have the config yet.
 // We skip validation here or valid against empty object if schema allows?
 // For now, let's keep the logging behavior but note it's delegating
 this.logger.debug(`Plugin ${plugin.name} has configuration schema (config validation postponed)`);
 return;
 }
 this.configValidator.validatePluginConfig(plugin, config);
}

config is always undefined here, so the early return always fires. "Postponed" to nothing: git grep validatePluginConfig finds no other caller outside PluginConfigValidator's own unit test.

2. There is nothing for it to postpone to. kernel.use(plugin) (packages/core/src/kernel.ts:198) hands pluginLoader.loadPlugin(plugin) the Plugin object only. A plugin factory captures its config in a closure — createRestApiPlugin(config) is the model — so no config value ever crosses into the kernel, and PluginMetadata carries no field for one. Even a correct validatePluginConfig(metadata, config) call would have nothing to pass.

3. No kernel plugin in the repo declares configSchema. git grep -n "configSchema:" packages -- ':!**/dist/**' ':!**/CHANGELOG.md' returns 20 hits and none is a kernel Plugin: they are automation node-executor JSON schemas (service-automation/src/builtin/*), the datasource driver catalog, plugin-approvals' approval-node descriptor, and spec/test declarations. So PluginConfigValidator — ~200 lines with its own unit test, its own formatZodErrors, validatePartialConfig and getDefaultConfig — has zero live consumers.

Why it matters

PluginMetadata.configSchema reads, at every author's call site, as the declared way to validate a plugin's configuration. It is documented as such (packages/core/ADVANCED_FEATURES.md:304, ADR-0025's "Config" section: "PluginConfigValidator validates plugin config against the plugin's schema"). A plugin author who declares one gets a debug line and no validation — the declared-not-enforced shape, one layer up from the one #11637 closes.

Not prejudged

Three shapes, and the choice is a real call:

• Wire the config through. Give Plugin/PluginMetadata a config field the factory populates, and pass it at loadPlugin. Makes the mechanism real for every plugin, and is the only shape that would let a plugin's schema cover its whole config rather than the slice a seam happens to reach.
• Retire it. Delete PluginConfigValidator and the configSchema field under ADR-0049 enforce-or-remove, with a tombstone, and let each plugin parse its own config at its own seam (which is what RestApiConfigSchema constrains api.version with a regex the REST server never runs — the seam casts instead of parsing, so api.version: '' is accepted and mounts the whole API at /api// #11637 does). A capability with zero consumers earning its keep on the strength of a docstring is the startup-scope case for removal.
• Fix the call and leave the surface. Pass config where one exists, keeping the field for the declarative/manifest loading path ADR-0025 describes.

Worth measuring before choosing: whether ADR-0025's manifest-driven load path ("configuration" in the plugin manifest) has a live call site that would have a config in hand, since that is the one caller for which the mechanism was designed.

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Generated by Claude Code

[os-trump]

Triage: pm:queue / domain:engine (lands in packages/core plugin-loader/kernel mechanism), type Task, measure-first charter (⛔ no route chosen before the measurement exists): measure whether ADR-0025's manifest-driven load path ("configuration" in the plugin manifest) has any live call site that would hold a config at loadPlugin time — the one caller the mechanism was designed for. Note the adjacent standing reading: #11332 already records the manifest configuration block itself has zero reads of its container, which is evidence toward "no live caller", but it must be re-taken on the current ref, not inherited.

Fork discipline: if the measurement confirms zero live path, the choice between the card's three routes reduces to retire-vs-wire on a documented published mechanism — deleting a published capability is a maintainer floor, so the executing seat reports the measurement and this card moves to the decision inbox with it attached, ⛔ not implemented. If a live manifest-path caller exists, "fix the call and leave the surface" becomes a plain repair the dev may implement under this card (with a pin that a declared configSchema actually executes).

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Generated by Claude Code