# matrix_sync

One-shot sync with a short server-side timeout. Returns new events, invites, and joined-room deltas since

Agent View of the PolicyLayer registry record for `matrix_sync`. HTML page: https://policylayer.com/tools/kh0pper-crow/matrix-sync

## Facts

- Tool: `matrix_sync`
- Server: Crow (`kh0pper/crow`) — https://policylayer.com/tools/kh0pper-crow.md
- Homepage: https://github.com/kh0pper/crow
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "matrix_sync",
    "arguments": {}
  }
}
```

## Why matrix_sync is rated Low

The matrix_sync tool retrieves synchronization data from a Matrix server (new events, invites, room changes) without modifying, executing, or deleting anything. This is a standard Read operation. Severity is low because it only accesses the authenticated user's view of their own data and events, with no blast radius beyond information disclosure of the user's own collaboration data.

From the tool's own definition: "Tool description states it 'Returns new events, invites, and joined-room deltas' — pure retrieval of state changes with no modification, deletion, or execution of commands. The timeout mechanism indicates it is a polling/sync operation for reading data."

## Use case

AI agents call matrix_sync to retrieve information from Crow without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Crow:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "matrix_sync": {}
  }
}
```

## Other tools on Crow (586)

- `caddy_remove_site` — Destructive — https://policylayer.com/tools/kh0pper-crow/caddy-remove-site.md
- `crow_bookstack_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-bookstack-delete.md
- `crow_campaign_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-campaign-delete.md
- `crow_data_write` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-data-write.md
- `crow_deactivate_server` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-deactivate-server.md
- `crow_delete_bot_schedule` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-bot-schedule.md
- `crow_delete_context_section` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-context-section.md
- `crow_delete_file` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-file.md
- `crow_delete_memory` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-memory.md
- `crow_delete_post` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-post.md
- `crow_delete_setlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-setlist.md
- `crow_frigate_set_detect` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-frigate-set-detect.md
- `crow_glasses_undo_last_append` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-glasses-undo-last-append.md
- `crow_identity_revoke` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-identity-revoke.md
- `crow_kb_delete_article` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-kb-delete-article.md
- `crow_linkding_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-linkding-delete.md
- `crow_media_playlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-media-playlist.md
- `crow_media_remove_source` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-media-remove-source.md
- `crow_miniflux_remove_feed` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-miniflux-remove-feed.md
- `crow_remove_backend` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-remove-backend.md
- `crow_remove_from_setlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-remove-from-setlist.md
- `crow_revoke_access` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-revoke-access.md
- `crow_revoke_instance` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-revoke-instance.md
- `crow_shiori_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-shiori-delete.md
- `crow_tax_purge_return` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-tax-purge-return.md
- `crow_trilium_delete_note` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-trilium-delete-note.md
- `crow_vikunja_delete_task` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-vikunja-delete-task.md
- `crow_wallabag_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-wallabag-delete.md
- `crowdsec_delete_decision` — Destructive — https://policylayer.com/tools/kh0pper-crow/crowdsec-delete-decision.md
- `fw_defederate` — Destructive — https://policylayer.com/tools/kh0pper-crow/fw-defederate.md
- …and 556 more: https://policylayer.com/tools/kh0pper-crow.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=kh0pper-crow · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/kh0pper-crow