run_manifest_validation always fails: schema with key or id "http://json-schema.org/draft-06/schema" already exists

Summary

run_manifest_validation fails for every manifest on @ui5/mcp-server@0.2.20, including a 10-line minimal one. It never reaches actual validation — it throws while building the Ajv validate function. Both code paths in createValidationFunction.ts are affected (Draft-07 and 2020-12), so it reproduces regardless of the manifest's _version.

Steps to reproduce

1. Create a minimal manifest:

{
  "_version": "1.60.0",
  "sap.app": {
    "id": "x.y",
    "type": "application",
    "applicationVersion": { "version": "1.0.0" }
  },
  "sap.ui5": {
    "dependencies": { "minUI5Version": "1.120.0", "libs": { "sap.m": {} } }
  }
}

2. Call the tool:

{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{
  "name":"run_manifest_validation",
  "arguments":{"manifestPath":"<abs-path>/webapp/manifest.json"}}}

Expected: a validation result.
Actual: isError: true.

Server log leading up to it:

[info] tools:run_manifest_validation:runValidation: Using manifest version: 1.60.0
[info] utils:ui5Manifest: Fetched UI5 manifest schema from https://raw.githubusercontent.com/UI5/manifest/v1.60.0/schema.json
[info] ...createValidationFunction: Using Draft-07 validation (detected from $schema: http://json-schema.org/draft-07/schema#)
[info] ...createValidationFunction: Loading external schema: https://adaptivecards.io/schemas/adaptive-card.json
[info] ...createValidationFunction: Loading external schema: https://json-schema.org/draft-06/schema
[error] utils: An internal server error occurred:
[error] utils: Failed to create UI5 manifest validate function: schema with key or id "http://json-schema.org/draft-06/schema" already exists

Full MCP response:

{"result":{"content":[{"type":"text","text":"Failed to create UI5 manifest validate function: schema with key or id \"http://json-schema.org/draft-06/schema\" already exists"}],"isError":true}}

Root cause

Thrown by Ajv#_checkUnique (ajv/dist/core.js:466). Ajv keeps a schema
registry indexed by $id; _checkUnique refuses to register a second
document under an $id that is already present in this.schemas /
this.refs. The draft-06 schema document fetched from the network
identifies itself with the same $id the server has already registered
manually — hence the collision on every run, not just some.

What triggers that network fetch is an http:// vs https:// mismatch.
In src/tools/run_manifest_validation/createValidationFunction.ts the
meta-schema is registered under the http:// URI only:

// createUI5ManifestValidateFunctionDraft07 — createValidationFunction.ts:173 (main)
ajv.addMetaSchema(draft06MetaSchema, "http://json-schema.org/draft-06/schema#");

But the Adaptive Card schema — pulled in from the UI5 manifest schema and
already special-cased in loadSchema — declares:

$schema: "https://json-schema.org/draft-06/schema#"     // note: https

Ajv finds no meta-schema registered under the https:// key, falls back to
loadSchema("https://json-schema.org/draft-06/schema"), and fetches it. The
fetched document self-identifies as $id: "http://json-schema.org/draft-06/schema#"
— colliding with the one registered on line 173.

The same applies to createUI5ManifestValidateFunction2020 (lines 78-79),
which registers both draft-06 and draft-07 under http:// keys only. All
three addMetaSchema calls are still http://-only on main, so this is
not fixed in an unreleased commit either.

Suggested fix

Register the https:// aliases alongside the existing http:// ones:

ajv.addMetaSchema(draft06MetaSchema, "http://json-schema.org/draft-06/schema#");
ajv.addMetaSchema(draft06MetaSchema, "https://json-schema.org/draft-06/schema#");

and the same for draft-07 in the 2020-12 path.

Schema versions tested

Reproduced standalone against the real UI5 manifest schemas, with the same
Ajv version and the same options the server uses (strict: false,
unicodeRegExp: false, identical loadSchema):

Schema	As of 0.2.20	With https alias
Draft-07 (v1.60.0 tag)	FAILS — already exists	compiles
2020-12 (main schema)	FAILS — already exists	compiles

Workaround

Validate against the official schema directly with Ajv, skipping the
server. One caveat worth documenting separately: each tag in UI5/manifest
ships the _version enum of the previous version (tag v1.60.0 only
accepts up to 1.59.0), so validating a 1.60.0 manifest against its own
tag yields a false positive on _version. Validating against main does
not have this issue.

Environment

@ui5/mcp-server	0.2.20 (latest published)
ajv	^8.20.0 (as declared by the package)
Node.js	v24.21.0
npm	11.19.0
OS	Windows 11
Launched via	npx -y @ui5/mcp-server (stdio)

Other tools in the same server process work fine — run_ui5_linter,
get_api_reference, get_project_info and get_version_info all returned
normally against the same project.

Start in src/tools/run_manifest_validation/createValidationFunction.ts, especially the Draft-07 and 2020-12 validation functions and their addMetaSchema calls. Reproduce with the minimal manifest and run_manifest_validation, then verify both schema paths compile and return a validation result without the duplicate draft-06 schema error.