Canvas-mcp canvas-bulk-grading
Bulk grading workflows for Canvas LMS assignments using rubrics. Covers single grading, batch grading, and code execution strategies with safety-first dry runs.
git clone https://github.com/vishalsachdev/canvas-mcp
T=$(mktemp -d) && git clone --depth=1 https://github.com/vishalsachdev/canvas-mcp "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/canvas-bulk-grading" ~/.claude/skills/vishalsachdev-canvas-mcp-canvas-bulk-grading && rm -rf "$T"
skills/canvas-bulk-grading/SKILL.mdCanvas Bulk Grading
Grade Canvas LMS assignments efficiently using rubric-based workflows. This skill requires the Canvas MCP server to be running and authenticated with an instructor or TA token.
Prerequisites
- Canvas MCP server running and connected
- Authenticated with an educator (instructor/TA) Canvas API token
- Assignment must exist and have submissions to grade
- Rubric must already be created in Canvas and associated with the assignment (Canvas API cannot reliably create rubrics -- use the Canvas web UI for that)
Workflow
Step 1: Gather Assignment and Rubric Information
Before grading, retrieve the assignment details and its rubric criteria.
get_assignment_details(course_identifier, assignment_id)
Then get the rubric. Use
get_assignment_rubric_details if the rubric is already linked to the assignment, or list_all_rubrics to browse all rubrics in the course:
get_assignment_rubric_details(course_identifier, assignment_id) list_all_rubrics(course_identifier) get_rubric_details(course_identifier, rubric_id)
Record the criterion IDs (often prefixed with underscore, e.g.,
_8027) and rating IDs from the rubric response. These are required for rubric-based grading.
Step 2: List Submissions
Retrieve all student submissions to determine how many need grading:
list_submissions(course_identifier, assignment_id)
Note the
user_id for each submission and the workflow_state (submitted, graded, pending_review). Count the submissions that need grading to determine which strategy to use.
Step 3: Choose a Grading Strategy
Use this decision tree based on the number of submissions to grade:
How many submissions need grading? | +-- 1-9 submissions | Use grade_with_rubric (one call per submission) | +-- 10-29 submissions | Use bulk_grade_submissions (concurrent batch processing) | Set max_concurrent: 5, rate_limit_delay: 1.0 | ALWAYS run with dry_run: true first | +-- 30+ submissions OR custom grading logic needed Use execute_typescript with bulkGrade function 99.7% token savings -- grading logic runs locally ALWAYS run with dry_run: true first
Strategy A: Single Grading (1-9 submissions)
Call
grade_with_rubric once per student:
grade_with_rubric( course_identifier, assignment_id, user_id, rubric_assessment: { "criterion_id": { "points": <number>, "rating_id": "<string>", // optional "comments": "<string>" // optional per-criterion feedback } }, comment: "Overall feedback" // optional )
Strategy B: Bulk Grading (10-29 submissions)
Always dry run first. Build the grades dictionary mapping each user ID to their grade data, then validate before submitting:
bulk_grade_submissions( course_identifier, assignment_id, grades: { "user_id_1": { "rubric_assessment": { "criterion_id": {"points": 85, "comments": "Good analysis"} }, "comment": "Overall feedback" }, "user_id_2": { "grade": 92, "comment": "Excellent work" } }, dry_run: true, // VALIDATE FIRST max_concurrent: 5, rate_limit_delay: 1.0 )
Review the dry run output. If everything looks correct, re-run with
dry_run: false.
Strategy C: Code Execution (30+ submissions)
For large classes or custom grading logic, use
execute_typescript to run grading locally. This avoids loading all submission data into the conversation context.
execute_typescript(code: ` import { bulkGrade } from './canvas/grading/bulkGrade.js'; await bulkGrade({ courseIdentifier: "COURSE_ID", assignmentId: "ASSIGNMENT_ID", gradingFunction: (submission) => { // Custom grading logic runs locally -- no token cost const notebook = submission.attachments?.find( f => f.filename.endsWith('.ipynb') ); if (!notebook) return null; // skip ungraded return { points: 100, rubricAssessment: { "_8027": { points: 100 } }, comment: "Graded via automated review" }; } }); `)
Use
search_canvas_tools("grading", "signatures") to discover available TypeScript modules and their function signatures before writing code.
Token Efficiency
The three strategies have very different token costs:
| Strategy | When | Token Cost | Why |
|---|---|---|---|
| 1-9 submissions | Low | Few round-trips, small payloads |
| 10-29 submissions | Medium | One call with batch data |
| 30+ submissions | Minimal | Grading logic runs locally; only the code string is sent. 99.7% savings vs loading all submissions into context |
The key insight: as submission count grows, sending grading logic to the server (code execution) is far cheaper than bringing all submission data into the conversation.
Safety Rules
- Always dry run first. For
, setbulk_grade_submissions
before the real run. Review the output for correctness.dry_run: true - Verify the rubric before grading. Confirm criterion IDs, point ranges, and rating IDs match the assignment rubric. Mismatched IDs cause silent failures or incorrect grades.
- Spot-check before bulk. For Strategy B and C, grade 1-2 submissions manually with
first. Verify in Canvas that the grade and rubric feedback appear correctly.grade_with_rubric - Respect rate limits. Use
andmax_concurrent: 5
(1 second between batches). Canvas rate limits are approximately 700 requests per 10 minutes.rate_limit_delay: 1.0 - Do not grade without explicit instructor confirmation. Always present the grading plan (rubric mapping, point values, number of students affected) and wait for approval before submitting grades.
Example Prompts
- "Grade Assignment 5 using the rubric"
- "Show me the rubric for the midterm project and grade all submissions"
- "Bulk grade all ungraded submissions for Assignment 3 -- give full marks on criterion 1 and 80% on criterion 2"
- "How many submissions still need grading for the final paper?"
- "Dry run bulk grading for Assignment 7 so I can review before submitting"
- "Use code execution to grade all 150 homework submissions with custom logic"
Error Recovery
| Error | Cause | Action |
|---|---|---|
| 401 Unauthorized | Token expired or invalid | Regenerate Canvas API token |
| 403 Forbidden | Not an instructor/TA for this course | Verify Canvas role |
| 404 Not Found | Wrong course, assignment, or rubric ID | Re-check IDs with or |
| 422 Unprocessable | Invalid rubric assessment format | Verify criterion IDs and point ranges match the rubric |
| Partial failures in bulk | Some grades submitted, others failed | Check the response for per-student status; retry only failed ones |