cursorrules

A set of coding rules for a Todoist AI server, including restrictions on how tool inputs are defined. It explains how to represent optional fields and requests to clear them.

In plain words
What is it for?
Use it when changing Todoist tool parameters, handling removed or unassigned values, updating schemas, or checking the server build and tests.
Why use it?
It helps avoid schema formats that make the Google Gemini API fail and keeps code, tests, and documentation aligned.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/doist/todoist-mcp/cursorrules
Clone the repo
git clone --depth 1 https://github.com/Doist/todoist-mcp

Made for: Cursor.

Per session 223 This file is loaded in full into every session.
When invoked 223 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00223 $0.00223
Opus 5 $0.00112 $0.00112
Sonnet 5 $0.00045 $0.00045
Haiku 4.5 $0.00022 $0.00022

Measured 2d ago against content hash e60db0c8926a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cursorrules scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.cursorrules · 38 lines

What it actually says

Todoist AI MCP Server - Cursor Rules

Critical: Tool Schema Compatibility

NEVER use .nullable() in tool schemas

  • Google Gemini API fails with nullable types in OpenAPI 3.1 format
  • Use .optional() only for optional string fields
  • See PR #181 for reference

Pattern for clearing optional fields:

// ❌ WRONG - breaks Gemini
fieldName: z.string().nullable().optional()

// ✅ CORRECT
fieldName: z.string().optional()

// Runtime handling for clearing:
if (fieldValue === null || fieldValue === 'remove') {
    updateArgs = { ...updateArgs, fieldName: null }
}

Use special strings for removal:

  • Use "unassign" for assignments
  • Use "remove" for other clearable fields
  • Document in schema descriptions

Testing Requirements

  • Add tests for new parameters
  • All 333+ tests must pass
  • Verify build and type-check

Documentation

  • Update schema descriptions
  • Update src/mcp-server.ts guidelines
  • Add usage examples
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 38 lines · 223 tokens per session scan A e60db0c8926a

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository Doist/todoist-mcp (539 stars, last pushed 2d ago), licensed MIT. It adds 223 tokens to every session, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.