What causes "Original app model config not found" in langgenius/dify?

Initialize the app's AppModelConfig before updating — create a default config row or use the app-setup flow that bootstraps it.

langgenius/dify · error · ValueError

invalid_param

invalid_param

Error message

Original app model config not found

What it means

A raw ValueError('Original app model config not found') raised in AppModelConfigApi.post when an AGENT_CHAT (or agent-with-session) app has no existing AppModelConfig row (api/controllers/console/app/model_config.py:117-119). The handler needs the original config to decrypt/migrate agent tool parameters; without it, it cannot safely produce the new config. Flask translates the ValueError into a 400 with code invalid_param.

Source

Thrown at api/controllers/console/app/model_config.py:119

        # validate config
        model_configuration = AppModelConfigService.validate_configuration(
            tenant_id=current_tenant_id,
            config=cast(dict, request.json),
            app_mode=AppMode.value_of(app_model.mode),
            session=session,
        )

        new_app_model_config = AppModelConfig(
            app_id=app_model.id,
            created_by=current_user_id,
            updated_by=current_user_id,
        )
        new_app_model_config = new_app_model_config.from_model_config_dict(model_configuration)

        if app_model.mode == AppMode.AGENT_CHAT or app_model.is_agent_with_session(session=session):
            original_app_model_config = app_model.app_model_config_with_session(session=session)
            if original_app_model_config is None:
                raise ValueError("Original app model config not found")
            agent_mode = original_app_model_config.agent_mode_dict
            # decrypt agent tool parameters if it's secret-input
            parameter_map = {}
            masked_parameter_map = {}
            tool_map = {}
            for tool in agent_mode.get("tools") or []:
                if not isinstance(tool, dict) or len(tool.keys()) <= 3:
                    continue

                agent_tool_entity = AgentToolEntity.model_validate(tool)
                # get tool
                try:
                    tool_runtime = ToolManager.get_agent_tool_runtime(
                        tenant_id=current_tenant_id,
                        app_id=app_model.id,
                        agent_tool=agent_tool_entity,
                        user_id=current_user_id,
                    )

View on GitHub (pinned to ef8544b173)

Solutions

Initialize the app's AppModelConfig before updating — create a default config row or use the app-setup flow that bootstraps it.
Verify app_model.app_model_config_id is non-null and points to an existing AppModelConfig row in the DB.
If the row was accidentally deleted, restore from a backup or recreate via AppModelConfig.from_model_config_dict with the default agent template.
Avoid manually mutating the apps/app_model_configs tables; use the console API to manage configs.

Defensive patterns

Strategy: validation

Validate before calling

// Before POSTing a config update for an agent-chat app, confirm a config exists
const app = await fetch(`/console/apps/${appId}`).then(r=>r.json())
if (app.mode === 'AGENT_CHAT' && !app.app_model_config_id) {
  await initAppConfig(appId) // bootstrap a default config first
}
await updateModelConfig(appId, config)

Try / catch

try {
  await updateModelConfig(appId, config)
} catch (e) {
  if (e.code === 'invalid_param' && /Original app model config/.test(e.message)) {
    await initAppConfig(appId); return updateModelConfig(appId, config)
  }
  throw e
}

Prevention

Never manually delete AppModelConfig rows.
Ensure app-creation flows initialize the config for agent-chat apps.
Audit app_model_config_id is non-null after migrations.

When it happens

Trigger: POSTing an updated model config to an AGENT_CHAT app that has no AppModelConfig attached — e.g. the app was created but its config row was never initialized, was deleted, or the app is mid-migration. The check is `app_model.app_model_config_with_session(session)` returning None.

Common situations: App created via a path that skipped config initialization; manual DB edit deleted the config row; migration/import left the app in a partial state; agent chat app whose app_model_config_id is null.

Related errors

AI-assisted analysis of langgenius/dify@ef8544b173 (2026-08-12). Data as JSON: /api/errors/b29a5f780a162cc0. Report an issue: GitHub.