Use this to test a server without running it. Replays a previously recorded cassette offline and runs all checks against the recorded responses. Useful in CI or when the live server is unavailable.
Part of the Mcp Observatory server.
Free to start. No card required.
AI agents call replay to retrieve information from Mcp Observatory without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though replay only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"replay": {}
}
}See the full Mcp Observatory policy for all 13 tools.
These attack patterns abuse exactly the kind of access replay gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Use this to test a server without running it. Replays a previously recorded cassette offline and runs all checks against the recorded responses. Useful in CI or when the live server is unavailable.. It is categorised as a Read tool in the Mcp Observatory MCP Server, which means it retrieves data without modifying state.
Register the Mcp Observatory MCP server in PolicyLayer and add a rule for replay: 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 Mcp Observatory. Nothing to install.
replay 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 replay 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 replay. 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.
replay is provided by the Mcp Observatory MCP server (@kryptosai/mcp-observatory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 13 Mcp Observatory tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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