Add support for JetBrains AI assistant

[davidt99]

JetBrains is using the new AI assistant that can work with other vendors (it has Junie and Claude Code).
As a result, it has a new format that is different from Junie.
If there is a guide on how to implement a new vendor, I can open a PR myself.

[dyoshikawa]

@davidt99 Thank you for your contributing intension.

Now, I've add How to add support for a new Tool/Feature section for you.

https://github.com/dyoshikawa/rulesync?tab=readme-ov-file#contributing

Now, I've create CONTRIBUTING.md for you.

[dyoshikawa]

JetBrains AI Assistant Specification Investigation Results

Overview

JetBrains AI Assistant and Junie are different products:

• AI Assistant: Real-time coding assistance (code completion, suggestions, VCS support, etc.)
• Junie: Autonomous AI agent (plans and executes tasks autonomously)

Both use different file structures and should be supported as separate targets.

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AI Assistant Features and File Formats

1. Rules (Project Rules)

Item	Details
File Format	Markdown (.md)
Location	.aiassistant/rules/*.md
Frontmatter	None (controlled via IDE settings)
Rule Types	Always, Manually, By model decision, By file patterns, Off

Reference: https://www.jetbrains.com/help/ai-assistant/configure-project-rules.html

2. MCP (Model Context Protocol)

Item	Details
Support Status	Full support since 2025.1
Configuration	Settings | Tools | AI Assistant | Model Context Protocol (MCP)
Transport	STDIO, Streamable HTTP
File Output	None (IDE settings-based)

Reference: https://www.jetbrains.com/help/ai-assistant/mcp.html

3. Ignore

Item	Details
File Format	gitignore format
Location	.aiignore (shared with Junie)

4. Commands (Prompt Library)

Item	Details
Configuration	Settings | Tools | AI Assistant | Prompt Library
File Output	None (IDE settings-based, stored internally as XML)
Team Sharing	Not available (personal settings only)

Note: Some Prompt Library features may have been deprecated in 2025.1 (YouTrack LLM-16985)

5. Subagents / Skills

Not supported (AI Assistant is not an autonomous agent)

---

Recommended Rulesync Implementation

Proposed Support (Add as new target aiassistant)

Feature	Support	Reason
rules	✅ Recommended	Markdown output to .aiassistant/rules/*.md
ignore	✅ Recommended	.aiignore (same file as Junie)
mcp	❌ Not supported	IDE settings-based, no file generation possible
commands	❌ Not supported	IDE settings-based, no file generation possible
subagents	❌ Not supported	Feature not available
skills	❌ Not supported	Feature not available

Implementation Details

File Structure Comparison (Junie vs AI Assistant):

# Junie
.junie/
  guidelines.md          # root rule
  memories/             # non-root rules
    *.md
  mcp/
    mcp.json
.aiignore

# AI Assistant
.aiassistant/
  rules/
    *.md                 # all rules (no root/non-root distinction)
.aiignore

AI Assistant Rules Characteristics:

• Rule types (Always/Manually/By file patterns, etc.) are set in IDE
• Rules are identified by filename
• Multiple files supported
• No frontmatter required (plain Markdown)

README.md Update Proposal

| Tool                  | rules | ignore | mcp   | commands | subagents | skills |
|------------------------|:-----:|:------:|:-----:|:--------:|:---------:|:------:|
| JetBrains AI Assistant |  ✅   |   ✅   |       |          |           |        |
| JetBrains Junie        |  ✅   |   ✅   |  ✅   |          |           |        |

---

Related Links

• AI Assistant: Configure project rules
• AI Assistant: Rules settings reference
• AI Assistant: MCP
• AI Assistant vs Junie FAQ

---

🤖 Generated with Claude Code

[davidt99]

I started working on this, but the AI assistant is in an early stage, and it's still buggy.
One issue I came across - the glob file paths are comma-separated globs that must be unquoted for some reason, and the YAML formatter always quotes strings.
I'll try to give it another try later.