browser_fill
Fill an input or textarea with the given value. ref is either an aria-ref token from browser.snapshot ('e7') OR a CSS selector ('input[name=email]'). Prefer the aria-ref token — it's stable and matches exactly what snapshot returned.
This record as markdown: /tools/io-github-saloprj-dialogbrain/browser-fill.md
What browser_fill does on Dialogbrain
AI agents invoke browser_fill to trigger actions in Dialogbrain. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
ref | string | Yes | |
value | string | Yes | |
page_id | string | Yes |
Parameters from the server's own tool schema.
Why browser_fill is rated High
This tool performs browser automation by filling form inputs, which constitutes executing an external browser action. It can inject arbitrary text into any input field (login forms, payment fields, message boxes), making it high severity due to potential for credential theft, unauthorized form submission, or data injection when misused by an AI agent.
From the tool's definition "Fill an input or textarea with the given value" — directly manipulates browser UI elements by injecting values into form fields using aria-ref tokens or CSS selectors
Attacks that exploit this kind of access
The rule that runs browser_fill safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Dialogbrain, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For browser_fill, this is the rule to start with:
browser_fill stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Dialogbrain, apply this rule, and every browser_fill call is checked against it from then on.
Questions about browser_fill
Fill an input or textarea with the given value. ref is either an aria-ref token from browser.snapshot ('e7') OR a CSS selector ('input[name=email]'). Prefer the aria-ref token — it's stable and matches exactly what snapshot returned. It is categorised as a Execute tool in the Dialogbrain MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
browser_fill accepts 3 parameters: ref, value, page_id. Required: ref, value, page_id. The full parameter table on this page comes from the server's own tool schema.
Register the Dialogbrain MCP server in PolicyLayer and add a rule for browser_fill: 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 Dialogbrain. Nothing to install.
browser_fill is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the browser_fill 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 browser_fill. 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.
browser_fill is provided by the Dialogbrain MCP server (https://api.dialogbrain.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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