Resolver error in reponse struct wth macro Schema

[PeterGumball]

Hello .

Testing the framework, at the moment a like it.

One Problem. I have the following response struct:

use chrono::{DateTime, Utc};
use rustapi_rs::prelude::*;
use serde::{Deserialize, Serialize};
use sqlx::FromRow;
use uuid::Uuid;

#[derive(Debug, Clone, Serialize, FromRow, Schema)]
pub struct Tag {
    pub id: Uuid,
    pub tag: String,
    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
}

On the docs page i get the following error:

Resolver error at paths./tags.post.responses.201.content.application/json.schema.properties.created_at.$ref
Could not resolve reference: Could not resolve pointer: /components/schemas/DateTime does not exist in document
Resolver error at paths./tags.post.responses.201.content.application/json.schema.properties.id.$ref
Could not resolve reference: Could not resolve pointer: /components/schemas/Uuid does not exist in document
Resolver error at paths./tags.post.responses.201.content.application/json.schema.properties.updated_at.$ref
Could not resolve reference: Could not resolve pointer: /components/schemas/DateTime does not exist in document

I looked to the Utopia documentation, but don't found any solution.

Can you help?

[Tuntii]

Hi! 👋

Thanks a lot for testing RustAPIreally glad to hear you like it so far.

You’re absolutely right, and thanks for reporting this. What you’re seeing is a known limitation in the current OpenAPI / schema generation.

🔍 What’s happening?

Types like:

• chrono::DateTime<Utc>
• uuid::Uuid

are external types, and at the moment RustAPI does not automatically register them under components/schemas when generating the OpenAPI document.

Because of that, the spec ends up referencing:

/components/schemas/DateTime
/components/schemas/Uuid

but those schemas are never defined, which leads to the resolver errors you’re seeing in the docs page.

---

✅ Current Workarounds

Option 1: Map to OpenAPI primitives (recommended for now)

OpenAPI represents these types as strings, so you can adjust your response struct like this:

#[derive(Debug, Clone, Serialize, FromRow, Schema)]
pub struct Tag {
    pub id: String,          // UUID as string
    pub tag: String,
    pub created_at: String,  // ISO 8601 date-time
    pub updated_at: String,
}

This matches the OpenAPI formats:

• Uuid → string (format: uuid)
• DateTime<Utc> → string (format: date-time)

---

Option 2: Newtype wrappers

You can also wrap external types and derive Schema on your own types:

#[derive(Serialize, Schema)]
pub struct ApiUuid(pub Uuid);

#[derive(Serialize, Schema)]
pub struct ApiDateTime(pub DateTime<Utc>);

and then use ApiUuid / ApiDateTime in your response structs.

---

🛠 Roadmap / Fix

Proper support for common external types (Uuid, DateTime, etc.) is planned:

• Auto-register common external types in components/schemas
• Map them to correct OpenAPI formats (uuid, date-time)
• Improve error messages when a schema cannot be resolved

I’ll open an issue for this so it’s tracked and fixed properly.

Thanks again for the feedback — this kind of report really helps improve the framework. 🚀

[Tuntii]

Fixed in PR #9, thanks for reporting!

@PeterGumball

[PeterGumball]

Wow, that was a fast fix. Thank you. Now it works.

Keep on going this work.