tengu_v3_reference_history

SERVERTengu SOURCEHlobo-dev/tengu-mcp

Medium RISK CLASS

Category Write

Parameters 41 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/tengu-mcp/tengu-v3-reference-history.md

WHAT IT DOES

What tengu_v3_reference_history does on Tengu

AI agents use tengu_v3_reference_history to create or update resources in Tengu, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Tengu environment.

Parameter	Type	Required	Description
`as_of`	string	—
`symbol`	string	Yes	Path parameter 'symbol' (required).
`prefer_country`	string	—
`include_change_log`	boolean	—

Parameters from the server's own tool schema.

RISK

Why tengu_v3_reference_history is rated Medium

An AI agent can call tengu_v3_reference_history faster than any human can review: one bad instruction and it creates or modifies resources in Tengu by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs tengu_v3_reference_history safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Tengu, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For tengu_v3_reference_history, this is the rule to start with:

tengu_v3_reference_history Rate-limited

tengu_v3_reference_history stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "tengu_v3_reference_history": {
      "limits": [
        {
          "counter": "tengu_v3_reference_history_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Tengu, apply this rule, and every tengu_v3_reference_history call is checked against it from then on.

FAQ

Questions about tengu_v3_reference_history

What does the tengu_v3_reference_history tool do? +

IDENTIFIER HISTORY for one symbol — every identifier this security has ever been bound to, with the dates each binding started and ended, plus the dated events where the ISSUER changed its name, ticker or CUSIP. This is the part of a crosswalk a current-state table cannot give you: it answers 'what was this on 2015-06-30', 'when did this CUSIP change' and 'what was this company called then'. Returns the timeline grouped by identifier rung (each entry with valid_from, valid_thru and whether it is still current), the issuer change events with what changed at each one, and — with as_of — the exact set of identifiers in force on that date. Use it to back-map a historical holdings file, to audit identifier drift in your own data, or to explain a ticker that no longer exists. STALENESS, stated rather than implied: the issuer change log is a VINTAGE snapshot that lags the live security master (as-of 2026-04-20 when this shipped, 104 days old, newest change event 2026-01-30). Its age in days and its expected cadence are in every response, and any disagreement between it and the live spine is named explicitly rather than blended into one confident answer. Coverage is a number: 969,333 identifier bindings on file, 759,618 of them retired, 38,850 of 77,313 securities carrying at least one prior ticker. It is categorised as a Write tool in the Tengu MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does tengu_v3_reference_history accept? +

tengu_v3_reference_history accepts 4 parameters: as_of, symbol, prefer_country, include_change_log. Required: symbol. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on tengu_v3_reference_history? +

Register the Tengu MCP server in PolicyLayer and add a rule for tengu_v3_reference_history: 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 Tengu. Nothing to install.

What risk level is tengu_v3_reference_history? +

tengu_v3_reference_history is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit tengu_v3_reference_history? +

Yes. Add a rate_limit block to the tengu_v3_reference_history 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 tengu_v3_reference_history completely? +

Set action: deny in the PolicyLayer policy for tengu_v3_reference_history. 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 tengu_v3_reference_history? +

tengu_v3_reference_history is provided by the Tengu MCP server (Hlobo-dev/tengu-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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