Skip to content
POST/api/v1/traces/{traceId}/attachments

Attach a base64 blob to a trace span

Stores an inline base64 attachment (NOT multipart). Requires projectId + spanId + name + mimeType + dataBase64; max 1 MiB decoded. Returns 201. (Spec's multipart / 25 MB description is wrong.)

Authentication

Send Authorization: Bearer YOUR_API_KEY on every request. Generate API keys at /dashboard/api-keys.

Request body required

Example

{
  "projectId": "00000000-0000-0000-0000-000000000000",
  "spanId": "string",
  "name": "string",
  "mimeType": "<image/*, audio/*, video/*, text/*, appli>",
  "dataBase64": "<Base64 (optionally a data: URL). Max 1 M>",
  "metadata": {}
}
Schema
{
  "application/json": {
    "schema": {
      "type": "object",
      "required": [
        "spanId",
        "name",
        "mimeType",
        "dataBase64"
      ],
      "properties": {
        "projectId": {
          "type": "string",
          "format": "uuid",
          "description": "Required if not supplied via ?projectId or the eg_ key context."
        },
        "spanId": {
          "type": "string"
        },
        "name": {
          "type": "string",
          "maxLength": 255
        },
        "mimeType": {
          "type": "string",
          "description": "image/*, audio/*, video/*, text/*, application/json, or application/pdf."
        },
        "dataBase64": {
          "type": "string",
          "description": "Base64 (optionally a data: URL). Max 1 MiB decoded."
        },
        "metadata": {
          "type": "object",
          "additionalProperties": true
        }
      }
    }
  }
}

Response

201 example

{
  "success": true
}

All status codes

201Created.
400(no description)
401(no description)
413Attachment exceeds the 1 MiB (1048576-byte) limit.
429(no description)

Code samples

cURL

curl -X POST \
  https://evalguard.ai/api/v1/traces/{traceId}/attachments \
  -H "Authorization: Bearer $EVALGUARD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "projectId": "00000000-0000-0000-0000-000000000000", "spanId": "string", "name": "string", "mimeType": "<image/*, audio/*, video/*, text/*, appli>", "dataBase64": "<Base64 (optionally a data: URL). Max 1 M>", "metadata": {} }'

TypeScript

import { EvalGuard } from "@evalguard/sdk";

const client = new EvalGuard({ apiKey: process.env.EVALGUARD_API_KEY });

const response = await client.request({
  method: "POST",
  path: "/api/v1/traces/{traceId}/attachments",
  body: {
    "projectId": "00000000-0000-0000-0000-000000000000",
    "spanId": "string",
    "name": "string",
    "mimeType": "<image/*, audio/*, video/*, text/*, appli>",
    "dataBase64": "<Base64 (optionally a data: URL). Max 1 M>",
    "metadata": {}
  },
});
console.log(response);

Python

from evalguard import EvalGuard
import os

client = EvalGuard(api_key=os.environ["EVALGUARD_API_KEY"])

response = client.request(
    method="POST",
    path="/api/v1/traces/{traceId}/attachments",
    body={
    "projectId": "00000000-0000-0000-0000-000000000000",
    "spanId": "string",
    "name": "string",
    "mimeType": "<image/*, audio/*, video/*, text/*, appli>",
    "dataBase64": "<Base64 (optionally a data: URL). Max 1 M>",
    "metadata": {}
},
)
print(response)

Go

package main

import (
	"context"
	"fmt"
	"net/http"
	"os"
	"strings"
)

func main() {
	body := strings.NewReader(`{"projectId":"00000000-0000-0000-0000-000000000000","spanId":"string","name":"string","mimeType":"<image/*, audio/*, video/*, text/*, appli>","dataBase64":"<Base64 (optionally a data: URL). Max 1 M>","metadata":{}}`)
	req, _ := http.NewRequestWithContext(context.Background(), "POST", "https://evalguard.ai/api/v1/traces/{traceId}/attachments", body)
	req.Header.Set("Authorization", "Bearer "+os.Getenv("EVALGUARD_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil { panic(err) }
	defer resp.Body.Close()
	fmt.Println(resp.Status)
}

Errors

400401413429

Other Traces endpoints