Support Uint8Array / Buffer in api.stream* endpoints

[lilWolf011]

🚀 Feature Request: Native Binary Support Across All APIs

Hi Encore team 👋,

I’m a happy Encore user working with both standard APIs and streaming APIs (api.streamInOut, etc.). Currently, Encore APIs only support JSON-compatible types (string, number, boolean, object), which limits binary use cases across the board.

For example, this is not supported:

interface Payload {
  data: Uint8Array; // ❌ not currently allowed
}

This limitation applies not only to streaming APIs but to all Encore endpoints, which creates unnecessary friction when working with binary data.

---

🧩 Problem

Because Uint8Array or Buffer aren't supported in any endpoint type, we are forced to base64-encode binary payloads when sending data between client and server.

This results in:

📦 ~33% payload overhead due to base64
🧮 Additional CPU usage from base64 encode/decode
🔁 Increased complexity on both client and server

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✅ Proposed Solution

Add native support for Uint8Array (or Buffer) across all API definitions, including both standard and streaming endpoints:

interface Payload {
  data: Uint8Array;
}

This would enable efficient binary transport using formats like msgpack, Protobuf, or similar — without requiring manual encoding.

---

🎯 Benefits

Improved performance: smaller payloads, less CPU overhead
Cleaner code: no need for manual base64 encoding/decoding
Better developer experience: more natural handling of binary data
Consistency: same capability across all endpoint types
Future-friendly: enables high-throughput and real-time use cases

---

🙏 Summary

Problem: All Encore endpoints only allow JSON-serializable types
Impact: Inefficient workarounds required for binary data
Request: Add support for Uint8Array or Buffer across all APIs

Would love to see this in the roadmap — I’d be happy to help test or prototype if needed. Thanks again for the amazing work on Encore!

[tom-groves]

+1 please, this would be amazing!

[prodemy-prosigmaka]

+1

[dodiego]

+1