One API for every assessment type
From typed essays to handwritten equations, GradeLab scores every response format your assessment product needs. Rubric-based, criterion-level, with partial credit and alternate approaches.
Subjective Answer Scoring
Grade descriptive and long-form answers with step marking, partial credit, and alternate valid approaches.
Essay Grading
Score essays against your rubric. Criterion-level feedback, structure analysis, and evidence citations.
Short Answer Scoring
Grade typed short answers with semantic matching to model answers and key-point detection.
STEM Evaluation
Grade mathematics, physics, chemistry, and engineering answers including equations and diagrams.
Mixed-Format Scripts
Handle exam scripts with multiple question types in one submission. MCQ, short answer, essay, and diagram.
Custom Instructions
Define grading policies, pass/fail thresholds, and scoring rules per assessment or per question.
From submission to scored result
Create an assessment, send submissions, receive structured grades with feedback and confidence. Async webhooks for batch processing.
Create Assessment
Define your assessment with questions, model answers, rubrics, and scoring policies via API or dashboard.
Send Submissions
Submit student responses as typed text, uploaded files, or scanned images. Batch up to 500 per call.
AI Evaluation
GradeLab applies your rubric, scores each criterion, generates feedback, and assigns confidence levels.
Review & Approve
Low-confidence results route to a review queue. Approve, override, or adjust before publishing.
Receive Results
Get structured JSON with question-level marks, criterion scores, feedback, and confidence via webhook.
Sync to Your System
Write scores and feedback back to your LMS, ERP, or SIS through your existing connectors or our SDKs.
Create Assessment
Define your assessment with questions, model answers, rubrics, and scoring policies via API or dashboard.
Send Submissions
Submit student responses as typed text, uploaded files, or scanned images. Batch up to 500 per call.
AI Evaluation
GradeLab applies your rubric, scores each criterion, generates feedback, and assigns confidence levels.
Review & Approve
Low-confidence results route to a review queue. Approve, override, or adjust before publishing.
Receive Results
Get structured JSON with question-level marks, criterion scores, feedback, and confidence via webhook.
Sync to Your System
Write scores and feedback back to your LMS, ERP, or SIS through your existing connectors or our SDKs.
Google Classroom
Canvas
Blackboard
MoodleAssessment & Scoring API FAQ
What assessment types can the API score?
The API scores essays, short answers, subjective/descriptive answers, STEM (math, physics, chemistry), code submissions, and mixed-format assessments with multiple question types in one submission.
Does the API support rubric-based grading?
Yes. You define your rubric with criterion-level weights, descriptors, and scoring rules. Each criterion is scored independently with evidence. Rubrics can be reused across assignments and courses.
Can I define custom grading policies?
Yes. You can define grading policies, pass/fail thresholds, and scoring rules per assessment or per question. The API supports custom instructions and grading profiles.
How does the API handle mixed-format assessments?
The API handles exam scripts with MCQ, short answer, essay, and diagram questions in one submission. Each question type is scored appropriately and section-wise results are returned.
What SDKs are available?
SDKs are available for Python, Node.js, and PHP. A full OpenAPI 3.1 specification is provided so you can generate SDKs in any language.
How do I get sandbox access?
Book a demo and we will provide sandbox keys. The sandbox is fully functional and lets you test every endpoint before going live.
All GradeLab API products
AI Grading API
The broad API hub. Add AI grading to any education platform.
Handwritten Grading API
Grade scanned answer sheets, handwritten essays, and paper exams.
Embedded AI Grading
White-label AI grading UI inside your product. Your brand.
ERP AI Grading
Add AI grading to your education ERP examination module.
AI for On-Screen Marking
Turn your OSM into AI-assisted evaluation. Three modes.
Subjective Answer Grading API
Step marking, partial credit, and alternate valid approaches.
Exam Grading API
Grade paper and digital exams through one API.
LMS AI Grading
Add AI grading to your LMS via LTI, AGS, and OneRoster.
Add assessment scoring without building the AI
Book a demo and see the API grade multiple assessment types in real time. We'll walk you through integration architecture, deployment options, and pricing for your volume.
Book a Demo