Documentation

Setup & User Guide

Get from zero to grading in about 10 minutes.

Requirements

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macOS 11+ Big Sur, Monterey, Ventura, Sonoma, Sequoia — Intel & Apple Silicon
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Canvas API Token Instructor-level access to at least one Canvas course
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AI API Key Anthropic (Claude) or OpenAI account — choose one
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File Submissions Works with PDF, PNG, JPG, and most image formats

1 Install GradeBlaster

Download the latest .dmg from gradeblaster.com/download.

Open the .dmg file. A window will appear — drag GradeBlaster.app into your Applications folder.

Launch GradeBlaster from your Applications folder or Spotlight (⌘ Space → type GradeBlaster).

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First launch on macOS: If macOS says the app "can't be opened because Apple cannot check it for malicious software," go to System Settings → Privacy & Security and click Open Anyway. This only happens once.

2 Connect Canvas

GradeBlaster needs two things to connect to Canvas: your school's Canvas URL and a personal API access token.

Get Your Canvas API Token

  1. Log in to Canvas at your school's URL (e.g., yourschool.instructure.com)
  2. Click your profile icon (top-left corner) → Settings
  3. Scroll down to Approved Integrations
  4. Click + New Access Token
  5. Enter a purpose (e.g., "GradeBlaster") and an optional expiry date
  6. Click Generate Token and copy the token immediately — it won't be shown again
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Keep your token private. Anyone with your token can access Canvas as you. Store it securely. GradeBlaster saves it locally in your Mac's Application Support folder.

Enter Your Canvas Settings

  1. Open GradeBlaster → go to Settings (⚙ī¸ in the sidebar)
  2. Under Canvas, enter your Canvas URL and paste your API token
  3. Click Test Connection — you should see a green "Connected" status

3 Add Your AI API Key

GradeBlaster supports two AI providers. Choose one (or add both).

Anthropic (Claude) Recommended
  1. Go to console.anthropic.com
  2. Create an account or log in
  3. Navigate to API Keys → Create Key
  4. Copy the key (starts with sk-ant-...)
  5. Paste it into GradeBlaster Settings → AI Provider → Anthropic

Typical cost: ~$0.008 per student graded

OpenAI (GPT-4o)
  1. Go to platform.openai.com
  2. Create an account or log in
  3. Navigate to API keys → Create new secret key
  4. Copy the key (starts with sk-...)
  5. Paste it into GradeBlaster Settings → AI Provider → OpenAI

Typical cost: ~$0.010 per student graded

4 Create a Grading Profile

A Grading Profile is a reusable rubric template. You define the criteria; GradeBlaster applies them to every student automatically.

Creating Your First Profile

  1. In GradeBlaster, click Profiles (đŸŽ¯) in the sidebar
  2. Click + New Profile
  3. Give it a name (e.g., "Fashion Flats — Spring Semester")
  4. Set the total points for the assignment
  5. Add Visual criteria — things the AI will look for visually (e.g., "Label Placement", "Color Accuracy", "Centering")
  6. Add Technical criteria — file structure requirements (e.g., "Layer Naming", "File Format")
  7. For each criterion, set the point value and write a clear description the AI will use to evaluate it
  8. Optionally add Assignment Description text to have the AI check if submissions follow the brief
  9. Click Save Profile
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Writing good criteria: Be specific and measurable. Instead of "looks good," write "Garment is centered on the page with at least 0.5 inch margin on all sides." The more specific the criterion, the more consistent the AI grading.

5 Run Blast All

Blast All is the fastest way to grade an entire class. One click, walk away, come back to finished grades.

  1. Click ⚡ Blast All in the sidebar
  2. Select your Course from the dropdown (pulled live from Canvas)
  3. Select the Assignment you want to grade
  4. Select your Grading Profile
  5. Choose Post Mode:
    • Live — grades are posted to Canvas immediately, visible to students
    • Draft — grades are saved to Canvas but hidden until you unmute the assignment
    • Local — grades are saved locally only; nothing posted to Canvas
  6. Click ⚡ Blast All to start

GradeBlaster will download each submission, run AI analysis, score it against your criteria, write a comment, and post the result to Canvas. You'll see real-time progress, scores, and AI cost.

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A class of 30 students typically takes 3–8 minutes to grade, depending on file sizes and AI provider speed.

6 Step-by-Step Mode

For assignments where you want to review each grade before it's posted, use Step-by-Step Mode.

  1. Go to Grading (📋) in the sidebar
  2. Select your course, assignment, and profile
  3. Click Start Grading
  4. For each student, GradeBlaster will display the submission and AI analysis side-by-side
  5. Review the AI's suggested score and comment
  6. Click Accept to post as-is, Edit to adjust, or Skip to come back later

7 Activate Your License

GradeBlaster includes a 30-day free trial. After the trial, you'll need a license key to continue.

Purchasing a License

Visit gradeblaster.com/#pricing and choose a plan. After checkout, you'll receive a license key via email within seconds.

Activating Your License

  1. Open GradeBlaster → go to Settings → License
  2. Enter your license key (format: GBLST-XXXX-XXXX-XXXX-XXXX)
  3. Click Activate
  4. You should see "License Activated ✓" with your plan and expiry date
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Lost your license key? Visit gradeblaster.com/account and enter your email address — we'll resend your key instantly.

Tips & Best Practices

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Reuse Profiles

Build one profile per assignment type. A "Fashion Flats" profile works for any flats assignment — just select it each time.

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Use Draft Mode First

Run Blast All in Draft mode, review the grades in Canvas, then publish when you're satisfied. Makes corrections easy.

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Watch AI Costs

Each grading run shows the AI cost in real time. A full class of 30 students typically costs $0.15–$0.30 total.

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Be Specific in Criteria

The AI grades what you tell it to grade. Vague criteria produce inconsistent results. Measurable criteria produce consistent ones.

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Export Grade History

Use the History tab to export all grading sessions to CSV for your own records. Good for end-of-semester audits.

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Always Review Outliers

Sort grades by score after a Blast All run. Spot-check the lowest and highest grades to catch any AI misses.

Troubleshooting

Your API token may have expired or been revoked. Go to Canvas Settings → Approved Integrations, delete the old token, and generate a new one. Paste the new token into GradeBlaster Settings.

Check that your AI API key is correct in Settings. Also check your account balance at console.anthropic.com or platform.openai.com — a $0 balance will cause failures. Rate limit errors usually resolve by waiting 30 seconds and retrying.

Ensure the assignment has student submissions in Canvas. GradeBlaster can only grade assignments where students have uploaded files. Text-entry submissions (not file uploads) are not yet supported.

Purchase a license at gradeblaster.com/#pricing, then enter your key at Settings → License → Activate. If you already purchased and can't find your key, visit gradeblaster.com/account to resend it.

Go to System Settings → Privacy & Security. Scroll down to the Security section — you'll see a message about GradeBlaster. Click Open Anyway. Enter your Mac password if prompted. This is a one-time step.

Still stuck? We're happy to help.

Contact Support