# Retrieve a milestone

Operation ID: `getMilestone`

Group: PSA › Milestones

[Open in the interactive reference](https://docs.api.lensing.ai/lensing/v1/endpoints/getMilestone)

`GET /psa/milestones/{id}`

Read-only: Reads and returns; changes nothing.

Retrieves a milestone. The psaProjectId, invoiceId, productId, and productLineId on a milestone are numeric ids, not UUIDs, so you can't use them to read the project, invoice, product, or product line they point to.

## Parameters

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `Api-Version` | header | string · v1 | yes | The API version this request targets, named by its public identifier. Required on every request; omitting it, or naming a version this company does not have, is answered with 400. This document describes version `v1`. |
| `id` | path | string | yes | The unique identifier of the milestone you want to retrieve. Example: `"9b1c7f42-3d8a-4e05-b6c1-27fa5e903d18"`. |

## Response

`200` Success

Under `data` (getMilestoneOutput):

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `id` | string | yes | The unique identifier for the milestone. Example: `"9b1c7f42-3d8a-4e05-b6c1-27fa5e903d18"`. |
| `name` | string | no | The display name of the milestone. Example: `"Phase 1 delivery"`. |
| `description` | string | no | A free-form description of the milestone. |
| `amount` | decimal | no | The milestone amount, in the currency given by currency. Example: `"15000.00"`. |
| `currency` | string | no | The currency of amount. Format ISO 4217, for example 'USD'. Example: `"USD"`. |
| `dueDate` | date | no | The date the milestone is due for completion. Format YYYY-MM-DD. Example: `"2026-09-30"`. |
| `status` | string | no | The status of the milestone. Possible values: 'pending', 'accomplished', 'invoiced'. Example: `"pending"`. |
| `billable` | boolean | no | Whether the milestone is billable to a customer. Example: `true`. |
| `psaProjectId` | number | yes | The id of the PSA project this milestone belongs to. It is a numeric key, not the UUID that GET psa/projects/:id takes. Example: `32341`. |
| `invoiceId` | number | no | The id of the invoice this milestone has been billed on. Absent when the milestone has not been invoiced. It is a numeric key, not the UUID that GET accounting/invoices/:id takes. |
| `productId` | number | no | The id of the product this milestone is associated with. It is a numeric key, not the UUID that GET accounting/products/:id takes. |
| `productLineId` | number | no | The id of the product line this milestone is associated with. It is a numeric key, not the UUID that GET accounting/product-lines/:id takes. |
| `lastModifiedDate` | date-time | yes | The date and time the milestone record last changed, in UTC. Format YYYY-MM-DDTHH:mm:ss.sssZ. Example: `"2026-08-14T11:20:31.004Z"`. |

```json
{
  "data": {
    "id": "9b1c7f42-3d8a-4e05-b6c1-27fa5e903d18",
    "name": "Phase 1 delivery",
    "description": "<description>",
    "amount": "15000.00",
    "currency": "USD",
    "dueDate": "2026-09-30",
    "status": "pending",
    "billable": true,
    "psaProjectId": 32341,
    "invoiceId": 0,
    "productId": 0,
    "productLineId": 0,
    "lastModifiedDate": "2026-08-14T11:20:31.004Z"
  },
  "diagnostics": [
    {
      "code": "<code>",
      "message": "<message>",
      "severity": "error",
      "path": [
        "<path>"
      ],
      "details": "<details>"
    }
  ]
}
```

## Errors

| Code | Status |
| --- | --- |
| `NOT_FOUND` | 400 |

## Statuses

- `400` — Invalid request or business failure. Codes: NOT_FOUND
- `401` — The request carries no valid access token.
- `403` — Not authorized
- `404` — Not found
- `429` — Too many requests from this client address. The response has no body and no `Retry-After` header.
- `500` — Internal server error