vision.open_stream
Open a calibrated ocular stream (video, sequence, screen, render, or opt-in webcam).
This record as markdown: /tools/visionmcp/vision.open-stream.md
What vision.open_stream does on Visionmcp
AI agents call vision.open_stream to retrieve information from Visionmcp without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why vision.open_stream is rated Low
This tool opens and accesses visual input streams for observation/reading purposes. While it may access a webcam (which requires permission), the core function is data retrieval and passive monitoring of visual streams. There is no code execution, data modification, deletion, or financial impact. The primary risk is privacy-related (ambient visual capture), but the functional category is Read.
From the tool's definition 'Open a calibrated ocular stream' retrieves or observes visual data from streams (video, sequence, screen, render, webcam) without modifying or executing external operations.
Attacks that exploit this kind of access
The rule that runs vision.open_stream safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Visionmcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For vision.open_stream, this is the rule to start with:
vision.open_stream is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Visionmcp, apply this rule, and every vision.open_stream call is checked against it from then on.
Questions about vision.open_stream
Open a calibrated ocular stream (video, sequence, screen, render, or opt-in webcam). It is categorised as a Read tool in the Visionmcp MCP Server, which means it retrieves data without modifying state.
Register the Vision MCP server in PolicyLayer and add a rule for vision.open_stream: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Visionmcp. Nothing to install.
vision.open_stream is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the vision.open_stream rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for vision.open_stream. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
vision.open_stream is provided by the Vision MCP server (joshuahickscorp/visionmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Vision, and thousands of servers like it.
This server
Across the catalogue