nwis.streamflow.daily_values

SERVERApibase SOURCEapibase-mcp-client

Low RISK CLASS

Category Read

Parameters 41 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-whiteknightonhorse-apibase/nwis.streamflow.daily-values.md

WHAT IT DOES

What nwis.streamflow.daily_values does on Apibase

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

Parameter	Type	Required	Description
`site_no`	string	Yes	USGS gauge station number, 8–15 digits (e.g. "01646500" for Potomac River near DC). Use water.sites to find station numbers.
`end_date`	string	—	End date in YYYY-MM-DD format (e.g. "2026-06-30"). Defaults to today if omitted. Max range: 1 year.
`start_date`	string	—	Start date in YYYY-MM-DD format (e.g. "2026-01-01"). Defaults to 30 days ago if omitted.
`parameter_cd`	string	—	USGS parameter code. "00060" = discharge/streamflow (ft3/s, default), "00065" = gage height (ft), "00010" = water temperature (°C), "00095" = specific conductan

Parameters from the server's own tool schema.

RISK

Why nwis.streamflow.daily_values is rated Low

Tool retrieves historical hydrology data from public USGS sources with no side effects.

From the tool's definition Get historical daily mean streamflow values, trend analysis, drought monitoring, public domain data

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs nwis.streamflow.daily_values safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Apibase, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For nwis.streamflow.daily_values, this is the rule to start with:

nwis.streamflow.daily_values Allowed

nwis.streamflow.daily_values is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "nwis.streamflow.daily_values": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Apibase, apply this rule, and every nwis.streamflow.daily_values call is checked against it from then on.

FAQ

Questions about nwis.streamflow.daily_values

What does the nwis.streamflow.daily_values tool do? +

Get historical daily mean streamflow (discharge) values for a USGS gauge station over any date range. Returns one measurement per day (midnight UTC) in cubic feet per second (ft3/s). Also supports gage height (ft), water temperature (°C), specific conductance, and turbidity via parameter_cd. Ideal for trend analysis, drought monitoring, flood season review, and hydrology research. Coverage: 1,500+ active US streamflow stations, records from 1900s to present. Use water.sites to look up station numbers by state or bounding box. No auth — USGS public domain, unlimited calls. It is categorised as a Read tool in the Apibase MCP Server, which means it retrieves data without modifying state.

What parameters does nwis.streamflow.daily_values accept? +

nwis.streamflow.daily_values accepts 4 parameters: site_no, end_date, start_date, parameter_cd. Required: site_no. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on nwis.streamflow.daily_values? +

Register the Apibase MCP server in PolicyLayer and add a rule for nwis.streamflow.daily_values: 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 Apibase. Nothing to install.

What risk level is nwis.streamflow.daily_values? +

nwis.streamflow.daily_values is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit nwis.streamflow.daily_values? +

Yes. Add a rate_limit block to the nwis.streamflow.daily_values 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.

How do I block nwis.streamflow.daily_values completely? +

Set action: deny in the PolicyLayer policy for nwis.streamflow.daily_values. 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.

What MCP server provides nwis.streamflow.daily_values? +

nwis.streamflow.daily_values is provided by the Apibase MCP server (apibase-mcp-client). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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