Tools

The MCP server provides tools the AI can call to perform tasks. It is convenient to group them by the steps of working on a form.

Step	Tools
Figure out which API	choose_api (requirement in your own words → operator), get_context (context for a build step)
Find reference material	get_symbol_docs, list_symbols, find_recipe, search_docs
Build the form	plan_form (spec → FormIntent), generate_form (FormIntent → form files)
Check	validate_form: kind = code, json-schema, behaviors, bundle, layout
Report a problem	report_issue

The role of each tool is described in the Overview. Below are the details of validate_form and report_issue.

validate_form

Checks a form before it runs. Returns RF0xx diagnostics with the line, a "what to do" hint and the next call to make.

kind	What it checks
code	The form's TypeScript: unknown or wrongly imported @reformer symbols, operators outside their schema, removed API
json-schema	a renderer-json schema document
behaviors	compute cycles — from a list of { target, reads[] }
bundle	the FormIntent and the schema as a whole, cross-checked against each other
layout	the form module's file names against the canonical set (form.schema.ts, form.behavior.ts, form.validation.ts, …)

report_issue

Submits a report about an error and its solution for feedback collection.

Parameters:

Parameter	Type	Required	Description
error	string	Yes	Description of the error or problem
solution	string	Yes	Solution or fix
tags	string[]	No	Tags for categorization and analytics
context	object	No	Additional context (see below)

Structure of context:

Field	Type	Description
examples	array	Code examples with descriptions
examples[].description	string	Example description
examples[].code	string	Example code
relatedFiles	string[]	Paths to related files
notes	string	Additional notes

Recommended tags:

Format	Example	Description
category:<type>	category:behavior, category:validation	Category: schema, validation, behavior, react, types, other
agent:<name>	agent:claude, agent:cursor	AI agent name
severity:<level>	severity:critical, severity:minor	Problem severity

Returns:

Confirmation that the report was written successfully.

How it works:

1. The AI encounters an error while working with ReFormer
2. The AI solves the problem
3. The AI calls report_issue with a description of the error and the solution
4. The report is saved locally as a separate file — <project root>/.reformer/issue_reports/<timestamp>-<slug>.json

The directory can be overridden with the REFORMER_ISSUE_REPORTS_DIR environment variable (a relative path is resolved against the server's working directory). The project root is the nearest package.json with dependencies found upward from cwd; if there is none, reports are placed directly in cwd. The server returns the exact path in its response.

Example of AI usage:

AI found an error: "Cycle detected in computeFrom"
AI identified the cause: effect depends on the target field
AI calls report_issue:
  - error: "Infinite loop in computeFrom when effect depends on target"
  - solution: "Use peek() instead of .value to read target without dependency"
  - tags: ["category:behavior", "agent:claude", "severity:critical"]
  - context:
      examples:
        - description: "Wrong - creates a dependency"
          code: "const current = targetNode.value.value;"
        - description: "Correct - no dependency"
          code: "const current = targetNode.value.peek();"
      relatedFiles: ["packages/reformer/src/core/behavior/behaviors/compute-from.ts"]

Storage format (JSON):

One report per file, pretty-printed with indentation:

{
  "timestamp": "2026-01-15T10:30:00.000Z",
  "error": "...",
  "solution": "...",
  "tags": ["category:behavior"],
  "context": { "examples": [], "notes": "..." }
}

The file name is made of the timestamp and a short slug of the error. If two reports land in the same millisecond, a -2, -3, … suffix is added to the name — an existing file is never overwritten.

Why collect feedback?

Error reports help to:

• Identify common user problems
• Improve the documentation
• Find bugs in the library
• Understand which patterns cause difficulties

All data is stored locally on your computer.