Attaching evidence to multiple events

This cookbook explains how to upload an evidence file to multiple Mangrove events using the API.

Example Scenario

You have a single evidence file (e.g., a meter reading export) that needs to be attached to multiple events in your Mangrove project. Instead of uploading manually to each event, you can automate this by iterating over your event IDs and calling the API.

Uploading Evidence with Code

Prerequisites

Before starting, make sure you have:

A Mangrove API token with Data Collection permissions (read and write access)
A list of event IDs you want to attach evidence to
Your evidence files
You can use a tool like Postman to make the API calls.

Convert Evidence File to the right format

The API accepts evidence files as base64-encoded strings.Open Terminal and run:

base64 -i path/to/your/file.csv | pbcopy

This converts your file into base64 and copies it to your clipboard.

Upload to a Single Event

Use the Create evidence on event endpoint to attach evidence to each event.Here’s an example request to upload evidence to one event:

curl

curl -X POST "https://app.gomangrove.com/api/v1/events/evt_abc123/evidence" \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "evidences": [
      {
        "type": "file",
        "data": {
          "file": {
            "name": "meter_readings.csv",
            "type": "text/csv",
            "base64": "YOUR_BASE64_STRING"
          }
        }
      }
    ]
  }'

Upload to Multiple Events

To upload to multiple events, iterate over your list of event IDs. Here are examples in different languages:

#!/bin/bash
API_TOKEN="YOUR_API_TOKEN"
FILE_BASE64=$(base64 -i evidence.csv)
EVENT_IDS=("evt_001" "evt_002" "evt_003")

for EVENT_ID in "${EVENT_IDS[@]}"; do
  curl -X POST "https://app.gomangrove.com/api/v1/events/${EVENT_ID}/evidence" \
    -H "Authorization: Bearer $API_TOKEN" \
    -H "Content-Type: application/json" \
    -d "{
      \"evidences\": [{
        \"type\": \"file\",
        \"data\": {
          \"file\": {
            \"name\": \"evidence.csv\",
            \"type\": \"text/csv\",
            \"base64\": \"$FILE_BASE64\"
          }
        }
      }]
    }"
  echo "Uploaded to $EVENT_ID"
done

import requests
import base64

API_TOKEN = "YOUR_API_TOKEN"
EVENT_IDS = ["evt_001", "evt_002", "evt_003"]

# Read and encode the file
with open("evidence.csv", "rb") as f:
    file_base64 = base64.b64encode(f.read()).decode()

headers = {
    "Authorization": f"Bearer {API_TOKEN}",
    "Content-Type": "application/json"
}

for event_id in EVENT_IDS:
    response = requests.post(
        f"https://app.gomangrove.com/api/v1/events/{event_id}/evidence",
        headers=headers,
        json={
            "evidences": [{
                "type": "file",
                "data": {
                    "file": {
                        "name": "evidence.csv",
                        "type": "text/csv",
                        "base64": file_base64
                    }
                }
            }]
        }
    )
    print(f"{event_id}: {response.status_code}")

const fs = require('fs');

const API_TOKEN = 'YOUR_API_TOKEN';
const EVENT_IDS = ['evt_001', 'evt_002', 'evt_003'];

const fileBase64 = fs.readFileSync('evidence.csv').toString('base64');

async function uploadEvidence() {
  for (const eventId of EVENT_IDS) {
    const response = await fetch(
      `https://app.gomangrove.com/api/v1/events/${eventId}/evidence`,
      {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${API_TOKEN}`,
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          evidences: [{
            type: 'file',
            data: {
              file: {
                name: 'evidence.csv',
                type: 'text/csv',
                base64: fileBase64
              }
            }
          }]
        })
      }
    );
    console.log(`${eventId}: ${response.status}`);
  }
}

uploadEvidence();

If you’re attaching the same file to multiple events, encode it once and reuse the base64 string for each request.

Using Postman

You can also use Postman’s Collection Runner to upload evidence to multiple events without writing code.

Create a Collection and Request

Open Postman
Create a new Collection (e.g., “Mangrove Evidence Upload”)
Inside the collection, click Add Request

Configure the Request

URL:

POST https://app.gomangrove.com/api/v1/events/{{event_id}}/evidence

Authorization tab:

Set Type to Bearer Token
Paste your Mangrove API token

Headers tab:

Key	Value
Content-Type	application/json

Body tab:

Select raw and set format to JSON
Paste the following:

{
  "evidences": [
    {
      "type": "file",
      "data": {
        "file": {
          "name": "{{file_name}}",
          "type": "text/csv",
          "base64": "{{file_base64}}"
        }
      }
    }
  ]
}

The {{event_id}}, {{file_name}}, and {{file_base64}} variables will be populated from your CSV file.

Convert Evidence File to Base64

Open Terminal (macOS) and run:

base64 -i path/to/your/file.csv | pbcopy

This converts your file to base64 and copies it to your clipboard.

Prepare the Runner Data File

Create a file called events.csv with these columns:

Column	Description
event_id	The event ID to attach evidence to
file_name	File name displayed in Mangrove
file_base64	Base64 string of your evidence file

Example

event_id,file_name,file_base64
evt_001,evidence.csv,AAAABBBB...
evt_002,evidence.csv,AAAABBBB...
evt_003,evidence.csv,AAAABBBB...

If attaching the same file to multiple events, reuse the same base64 value across rows.

Run the Collection

In Postman, open your Collection
Click Run
Upload events.csv as the data file
Click Run

Postman will send one request per row in your CSV file. The number of successful responses should match the number of rows.

Getting Started

API Cookbooks

Production Data

Accounting and Reporting

Credit Inventory Management

Account Admin

Example Scenario

Uploading Evidence with Code

Using Postman

Example Scenario

​Uploading Evidence with Code

​Using Postman

Uploading Evidence with Code

Using Postman