proposal

A guided command for writing a structured feature proposal in a project documentation folder.

In plain words
What is it for?
It is for proposing new Mendix features and investigating related project code or documentation before implementation.
Why use it?
It turns an idea into a documented plan by asking about the goal, version support, MDL syntax, and BSON, the data format used by Mendix documents.

Command for Claude Code

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 commands/mendixlabs/mxcli/proposal
Clone the repo
git clone --depth 1 https://github.com/mendixlabs/mxcli

Made for: Claude Code.

Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,317 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00012 $0.01317
Opus 5 $0.00006 $0.00659
Sonnet 5 $0.00002 $0.00263
Haiku 4.5 $0.00001 $0.00132

Measured yesterday against content hash 2a3e39e29d06, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

proposal 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 yesterday.

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.

.claude/commands/mxcli-dev/proposal.md · 165 lines

How it starts

The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/mxcli-dev:proposal — Create Feature Proposal

Guide the contributor through creating a well-structured feature proposal for mxcli. The proposal goes in docs/11-proposals/PROPOSAL_<name>.md.

Process

Work through these phases interactively — ask the user questions, don't guess. Each phase produces concrete output.

Phase 1: Understand the Feature

Ask the user:

  1. What do you want to add? (one sentence)
  2. Why — what problem does this solve, or what user story does it enable?
  3. Which Mendix version introduced this capability? (affects version-gating)
  4. Does this add MDL syntax? (CREATE/ALTER/DROP/SHOW/DESCRIBE statements)
  5. Does this touch BSON serialization? (reading or writing Mendix documents)

If the user isn't sure about version or BSON, help them find out:

  • Version: check reference/mendixmodellib/reflection-data/ or Mendix release notes
  • BSON: check if similar features exist in sdk/mpr/parser*.go or sdk/mpr/writer*.go

Phase 2: BSON Investigation (if applicable)

CRITICAL: If the feature reads or writes Mendix documents, investigate the BSON structure BEFORE designing syntax. Wrong assumptions here cause CE errors in Studio Pro that are painful to debug.

  1. Find a working example — ask the user:

    • "Do you have a test .mpr project with this feature already configured in Studio Pro?"
    • If yes: use mxcli bson dump or mxcli bson discover to extract the BSON structure
    • If no: ask them to create a minimal example in Studio Pro first
  2. Extract the BSON structure:

    # Find the document type
    ./bin/mxcli -p project.mpr -c "SHOW STRUCTURE ALL" | grep -i <feature-name>
    
    # Dump the raw BSON
    ./bin/mxcli bson dump -p project.mpr --type "<BSON $Type>"
    
    # Or discover all instances of a type
    ./bin/mxcli bson discover -p project.mpr --pattern "<pattern>"
    
  3. Document the BSON structure in the proposal:

    • Storage name ($Type field) — verify against reference/mendixmodellib/reflection-data/
    • All fields with types and observed values
    • Any fields that use Mendix-internal IDs (pointers to other documents)
    • Note any counter-intuitive naming (like Parent/Child pointer inversion)

Read the full file on GitHub · 165 lines

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. yesterday First seen · 165 lines · 12 tokens per session scan A 2a3e39e29d06

Subscribe to this mod's changes

proposal is a command published in the GitHub repository mendixlabs/mxcli (115 stars, last pushed 2d ago), licensed Apache-2.0. It adds 12 tokens to every session and 1,317 once invoked, about $0.0001 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.