Grades API reference

Base URL: https://api.link.voshi.com/ltiaas/v1

All grade endpoints authenticate with your API key:

Authorization: Bearer ltiaas_<app-id>_<secret>

Submit a grade

POST /ltiaas/v1/grades
Content-Type: application/json

Creates the grade for a launch, or — if one already exists for that launch_id — updates it and re-syncs. See one grade per launch.

Request body

launch_idstringrequired

The launch to grade, from the launch JWT's launch_id claim. The launch must belong to your app and must have arrived with grade_passback: true.

scorenumberrequired

The score as a fraction from 0.0 to 1.0.

commentstringdefault:

A comment shown to the student alongside the grade.

activity_progressstringdefault: Completed

Completed or Submitted — whether the student has finished the activity.

grading_progressstringdefault: FullyGraded

FullyGraded or Pending — whether this score is final.

Example

curl

curl -X POST "https://api.link.voshi.com/ltiaas/v1/grades" \
    -H "Authorization: Bearer ltiaas_myappid_mysecret" \
    -H "Content-Type: application/json" \
    -d '{
          "launch_id": "I9gbX9ExUrt6",
          "score": 0.85,
          "comment": "Nice work!"
        }'

Python

import requests

resp = requests.post(
    "https://api.link.voshi.com/ltiaas/v1/grades",
    headers={"Authorization": "Bearer ltiaas_myappid_mysecret"},
    json={
        "launch_id": "I9gbX9ExUrt6",
        "score": 0.85,
        "comment": "Nice work!",
    },
)
resp.raise_for_status()
grade = resp.json()

Node

const resp = await fetch('https://api.link.voshi.com/ltiaas/v1/grades', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer ltiaas_myappid_mysecret',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    launch_id: 'I9gbX9ExUrt6',
    score: 0.85,
    comment: 'Nice work!',
  }),
})
const grade = await resp.json()

Response — 200

{
  "grade_id": "Gr8dEx",
  "launch_id": "I9gbX9ExUrt6",
  "score": 0.85,
  "sync_status": "synced",
  "sync_error": null,
  "submitted_at": "2026-07-27T18:10:00+00:00",
  "synced_at": "2026-07-27T18:10:01+00:00"
}

grade_idstring

The grade's ID — use it with GET a grade.

launch_idstring

The launch this grade belongs to.

scorenumber

The submitted fraction (0.0–1.0).

sync_statusstring

pending, synced, or failed. A failed sync still returns 200 — the failure is reported here so you can retry by re-POSTing.

sync_errorstring | null

Why the sync failed, when sync_status is failed.

submitted_atstring

When this score was submitted (ISO 8601). Updated on each resubmission.

synced_atstring | null

When the score reached the gradebook, or null if it hasn't.

Errors

Status	Message	Cause
422	score must be between 0 and 1	score outside 0.0–1.0.
422	activity_progress must be one of [...]	Value not Submitted or Completed.
422	grading_progress must be one of [...]	Value not FullyGraded or Pending.
422	This launch's location is not an assessment (grade passback is only allowed for assessment locations)	The launched location isn't type assessment.
422	Launch has no grade passback (no LMS line item)	The LMS never created a gradebook line item for this placement — the launch arrived with grade_passback: false.
404	Launch not found	Unknown launch_id, or a launch belonging to a different app (deliberately indistinguishable).
401	Missing Bearer API key / Invalid API key / …	Authentication problem — see Errors.

Get a grade

GET /ltiaas/v1/grades/{grade_id}

Returns the same shape as the submit response — useful for checking sync_status later.

curl

curl "https://api.link.voshi.com/ltiaas/v1/grades/Gr8dEx" \
    -H "Authorization: Bearer ltiaas_myappid_mysecret"

Python

import requests

resp = requests.get(
    "https://api.link.voshi.com/ltiaas/v1/grades/Gr8dEx",
    headers={"Authorization": "Bearer ltiaas_myappid_mysecret"},
)
resp.raise_for_status()
grade = resp.json()

Node

const resp = await fetch(
  'https://api.link.voshi.com/ltiaas/v1/grades/Gr8dEx',
  { headers: { Authorization: 'Bearer ltiaas_myappid_mysecret' } }
)
const grade = await resp.json()

Unknown grade IDs — and grades belonging to other apps — return 404 Grade not found.