Use this checklist when security architecture or DPO needs reproducible proof that Blekline governs Cursor IDE — before expanding hook rollout or signing a production SOW.
Setup prerequisites: Cursor MCP guide. For in-VPC pilots, run this on pilot laptops while the Enterprise implementation checklist sidecar path is in audit mode.
DPO guarantee statement
Blekline enforces at deterministic boundaries:
- Chat submit in Cursor IDE via hooks (block + clipboard — not silent in-place rewrite)
- Sensitive file reads (
.env, keys paths) - Shell commands and tool arguments via hooks where Cursor exposes them
- MCP tool calls via hook and/or Blekline proxy
- Production agent LLM/tool paths via ingress proxy and SDK
Honest limits: Cursor Cloud Agents do not support chat-submit or MCP-exec hooks today — production agents must use ingress/proxy. Native Cursor model HTTP is not wrapped. Activity stores metadata only by default; prompt bodies are not stored.
Guarantee matrix
| Control | Cursor IDE | Cloud Agent | Production ingress |
|---|---|---|---|
| Chat submit mask/block | Yes | No | Yes |
| Sensitive attachment block | Yes | No | N/A |
Read .env / keys | Yes | Yes | Policy |
| Shell exfil block | Yes | Yes | N/A |
| Tool Write redact | Yes | Yes | SDK/proxy |
| MCP exec guard | Yes | No | Proxy |
| Audit metadata | Yes | Partial | Yes |
| Silent auto-send in chat | No | No | N/A |
See Coverage & residuals for the full honesty matrix.
10-step verification
Record: Cursor version, OS, date, operator name.
| Step | Test | Pass criteria |
|---|---|---|
| 1 | MCP green | Settings → MCP: blekline + [blekline-proxy](/docs/definitions/mcp-proxy) connected |
| 2 | Hooks loaded | Settings → Hooks: 7× .cursor/hooks/blekline-*.sh (not bare node) |
| 3 | Chat block | Send prompt with email + fake AWS key → blocked, concise notice, clipboard has safe text |
| 4 | Chat passthrough | Cmd+V + Enter → allowed through (recognized resubmit) |
| 5 | MCP tool | Agent calls blekline_mask_prompt → masked JSON returned |
| 6 | Proxy | write_file with secrets via blekline-proxy → block or mask |
| 7 | Read deny | Agent Read .env → denied |
| 8 | Shell deny | Agent runs cat .env → denied |
| 9 | Write redact | Agent Write with API key in content → redacted before execute |
| 10 | Activity | Workspace Operations → Activity shows metadata only; note trace ID from block notice |
Smoke commands (blekline-oss)
git clone https://github.com/Blekline/blekline-oss
cd blekline-oss
pnpm install && pnpm build:packages
export BLEKLINE_WORKSPACE_TOKEN="blw_..."
export BLEKLINE_API_URL="https://app.blekline.com"
pnpm generate:mcp-configs --local
pnpm demo:cursor-hook-smoke
Quit and reopen Cursor after config generation (not just Reload Window).
Workspace requirements
- Workspace token with
mask:writeandevents:writescopes - Customer-owned eval workspace — do not use vendor demo or shared sample tokens for DPO retest
- Billing tryout or subscription active if cloud mask path is enabled (
promptMaskSource: cloud)
Explicitly out of scope
Do not promise in DPO review:
- Silent auto-send in native Cursor chat
- Full CASB / endpoint DLP replacement
- MCP hooks in Cursor Cloud Agents (platform limitation)
- SAML SSO (OIDC + SCIM shipped — see SSO & deployment)
- SOC 2 Type II attestation (roadmap)
Enterprise sandbox
Full OWASP ASI mapping, red-team scenarios, and compliance crosswalks for Cursor + MCP tracks ship in the enterprise sandbox (request via Compliance evidence or your Blekline operator).
Next steps: Cursor setup · Implementation checklist · Procurement pack · Open workspace