Companion Connector MCP

Local Companion MCP app for ChatGPT New App custom server connection.

V5 capabilities

This version is built for large local work, Fable handoff, screenshots/images, URL reading, media metadata, and future 21-service routing.

Core MCP tools

• search
• fetch
• register_file_pointer
• read_file_slice
• read_result_slice
• create_summary_job
• create_file_digest_job
• create_directory_inventory_job
• register_image_pointer
• ingest_image_base64
• get_image_data
• create_image_inspection_job
• ingest_chat_transcript
• ingest_attachment_base64
• create_fable_bundle
• run_fable_bundle

Fable and batch tools

• create_question_batch
• run_question_batch
• ask_fable_big
• create_fable_improvement_survey
• connector_health_report
• list_jobs
• list_fable_runs
• create_fable_prompt_file
• get_job_status
• list_registered_resources

URL/media/handoff tools

• fetch_url_text
• extract_links_from_url
• create_url_snapshot_job
• register_video_pointer
• create_media_metadata_job
• create_handoff_queue_item
• list_handoff_queue
• list_mcp_services
• describe_mcp_service

What it solves

• Big files are referenced by path instead of pasted into chat.
• Large questions can be written into local prompt bundles for Fable.
• Multiple questions can be batched into one file-backed request.
• URLs can be fetched into bounded snapshots.
• Links can be extracted from a page.
• Attachments can be stored as connector resources.
• Screenshots/images can be registered by path or small base64 payload.
• Media/video files can be registered and inspected with ffprobe when available.
• Fable can be given a bundle prompt file with transcript, attachment pointers, full text sections, image metadata, media metadata, and hashes.
• 21 planned MCP service folders are exposed as a service catalog.
• Outputs are written to results/ and read by slice.

Start locally

npm start

Default endpoint:

http://127.0.0.1:8788/mcp

Tests

npm test
npm run test:fable
npm run test:v4
npm run test:v5

Hidden PowerShell 7 startup

.\scripts\start-hidden.ps1

Stop by port:

.\scripts\stop-companion.ps1

Tunnel setup

See TUNNEL_SETUP.md.

Safety boundaries

• Reads are restricted to configured allowed roots.
• Connector writes stay under the connector workspace.
• Source folders are not modified by pointer registration.
• _AI_CHATS_ОБЩИЕ is not reorganized by this app.
• Large outputs are written to results/ and read by slice.
• Calls are logged by hash, not full arguments.
• Widget resource uses text/html;profile=mcp-app.

V6 additions

V6 adds a verified 100-improvement registry and audit layer:

• list_implemented_improvements
• audit_100_improvements
• create_support_bundle
• runtime_metrics
• validate_connector_config
• create_debug_snapshot

Files:

• docs/V6_100_IMPLEMENTED_IMPROVEMENTS.md
• docs/V6_100_IMPLEMENTED_IMPROVEMENTS.json

Test:

npm run test:v6

V7 no-window startup and 1000 forward improvements

Manual npm start no longer keeps a visible server console open. It starts the connector in the background through PowerShell 7.

Best daily start method with no popup:

wscript.exe .\CompanionConnector-START-HIDDEN.vbs

Or double-click:

CompanionConnector-START-HIDDEN.vbs

Install hidden startup at Windows logon:

.\scripts\install-hidden-task.ps1

Remove hidden startup task:

.\scripts\uninstall-hidden-task.ps1

V7 also adds a 1000-item forward improvement backlog. It is explicitly not falsely marked as implemented:

• docs/V7_1000_FORWARD_IMPROVEMENTS.md
• docs/V7_1000_FORWARD_IMPROVEMENTS.json

V7 tests:

npm run test:v7
npm run test:windowless

V8 read-only full-folder bridge

V8 adds tools for large read-only folder access without modifying the source folder:

• folder_explorer
• create_readonly_folder_manifest
• audit_readonly_folder_manifest
• create_readonly_folder_content_bundle
• read_folder_bundle_chunk
• search_folder_content_bundle
• create_fable_folder_handoff

Tested target:

J:\ПРОЕКТЫ\G01_All_About_Trading\G01_P09_All_for_TradingView\G01_P09_01_Project\TradingView_INDICATORS\IGOR_ENTER2\research_out

V8 test:

npm run test:v8

The source folder is only read. Manifest, chunks, hashes, and Fable guide are written under CompanionConnector results/.