---
title: "Upload a project Trail body attachment (JPEG/PNG, max 10 MB)"
method: POST
path: "/api/v1/{forge}/{project}/trails/{trailId}/attachments"
tags: ["Project Trails"]
---

# Upload a project Trail body attachment (JPEG/PNG, max 10 MB)

`POST /api/v1/{forge}/{project}/trails/{trailId}/attachments`

## Request

- Base URL: `https://entire.io` (the document declares no server; this is the origin it was published from)
- URL: `https://entire.io/api/v1/{forge}/{project}/trails/{trailId}/attachments`
- Auth: none declared

## Path parameters

- `forge` 'et' | 'gh', required
- `project` string, required
- `trailId` string, required

## Query parameters

- `project_id` string
- `filename` string

## Headers

- `Idempotency-Key` string

## Request body `image/jpeg`

- string, binary

## Response `201`

Attachment created

- object
  - `attachment` object, required
    - `id` string, required
    - `project_id` string, required
    - `trail_id` string, required
    - `filename` string, required
    - `content_type` string, required
    - `size_bytes` number, required
    - `is_ready` boolean, required
    - `kind` string, required
    - `created_by_account_id` string, required
    - `created_at` string, required
    - `width` number, nullable, required
    - `height` number, nullable, required

## Other responses

- `400`: Request refused or upstream unavailable
- `401`: Request refused or upstream unavailable
- `403`: Request refused or upstream unavailable
- `404`: Request refused or upstream unavailable
- `409`: Request refused or upstream unavailable
- `422`: Request refused or upstream unavailable
- `500`: Request refused or upstream unavailable
- `502`: Request refused or upstream unavailable
- `503`: Request refused or upstream unavailable

## Changes

- **2026-10-20** `74a5f2d632e5`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/entire/apis/entire-api/changes/api/v1/:forge/:project/trails/:trailId/attachments/post.md)

---

[API](https://skmtc.dev/entire/apis/entire-api.md) - [All operations](https://skmtc.dev/entire/apis/entire-api/llms.txt) - [OpenAPI document](https://skmtc.dev/entire/apis/entire-api/revisions/a24dfcc828d7?raw)