alibaba/nacos · error · NacosApiException

20005

20005

Error message

Prompt version already exists: {version}

What it means

Thrown by checkVersionNotExists when resourceManager.findVersion finds an existing row for the given version. Version names must be unique within a prompt. HTTP 409 RESOURCE_CONFLICT (code 20005). Called during createDraft and fork-from-version flows.

Source

Thrown at ai/src/main/java/com/alibaba/nacos/ai/service/prompt/PromptOperationServiceImpl.java:969

            if (page == null || page.getPageItems() == null || page.getPageItems().isEmpty()) {
                break;
            }
            all.addAll(page.getPageItems());
            if (page.getPageItems().size() < pageSize) {
                break;
            }
            pageNo++;
        }
        return all;
    }
    
    private void checkVersionNotExists(String namespaceId, String promptKey, String version)
        throws NacosException {
        AiResourceVersion existing =
            resourceManager.findVersion(namespaceId, promptKey, RESOURCE_TYPE_PROMPT,
                version);
        if (existing != null) {
            throw new NacosApiException(NacosException.CONFLICT, ErrorCode.RESOURCE_CONFLICT,
                "Prompt version already exists: " + version);
        }
    }
    
    private String resolveNextVersion(String namespaceId, String promptKey) {
        List<AiResourceVersion> allVersions = loadAllVersionRows(namespaceId, promptKey);
        if (allVersions.isEmpty()) {
            return DEFAULT_INITIAL_VERSION;
        }
        String maxVersion = null;
        for (AiResourceVersion v : allVersions) {
            if (v == null || !PromptVersionUtils.isValidVersion(v.getVersion())) {
                continue;
            }
            if (maxVersion == null
                || PromptVersionUtils.compareVersion(v.getVersion(), maxVersion) > 0) {
                maxVersion = v.getVersion();
            }

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Choose a different, incrementally higher version number (e.g. bump the patch segment).
2. Omit targetVersion entirely to let resolveNextVersion auto-assign the next available version.
3. List existing versions via getPromptDetail before creating a draft to pick a non-conflicting version.

Example fix

// before
service.createDraft(ns, key, null, "1.0.0", template, vars, null); // 1.0.0 exists

// after: let server pick next version
service.createDraft(ns, key, null, null, template, vars, null); // auto 1.0.1
// or specify explicitly
service.createDraft(ns, key, null, "1.0.1", template, vars, null);

// Check for existing versions before creating a draft
PromptMetaInfo meta = service.getPromptDetail(ns, key);
if (meta.getVersions().contains(targetVersion)) {
    // pick a different version or omit targetVersion for auto-increment
    return;
}

boolean versionIsFree = !service.getPromptDetail(ns, key).getVersions().contains(targetVersion);

try {
    service.createDraft(ns, key, basedOn, targetVersion, template, vars, msg);
} catch (NacosApiException e) {
    if (e.getErrCode() == NacosException.CONFLICT) {
        // version taken — bump and retry
    }
    throw e;
}

When it happens

Trigger: Calling createDraft with a targetVersion that already exists for this prompt; forking from an existing version and specifying a targetVersion that collides with a previously created version.

Common situations: Re-deploying a CI pipeline that hardcodes the same target version; forking without checking existing versions; two concurrent draft creations racing for the same version string.

Related errors

• MCP_SERVER_VERSION_EXIST
• CONFLICT
• CONFLICT
• Duplicate Runtime Endpoint: {}
• RESOURCE_CONFLICT

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/0025c491540b9180. Report an issue: GitHub.