Use when you need the full natal chart for interpretation, comparison, or downstream transit/progression work. Returns planets, houses, aspects, patterns, dignities, and Big Three. detail="compact" drops the per-aspect details (keeps aspects.summary counts) and per-pattern planet lists — saves ~1...
Risk signalsHigh parameter count (11 properties)
Part of the Celestine server.
Free to start. No card required.
AI agents call birth_chart to retrieve information from Celestine 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 birth_chart 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": {
"birth_chart": {}
}
}See the full Celestine policy for all 12 tools.
These attack patterns abuse exactly the kind of access birth_chart 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 when you need the full natal chart for interpretation, comparison, or downstream transit/progression work. Returns planets, houses, aspects, patterns, dignities, and Big Three. detail="compact" drops the per-aspect details (keeps aspects.summary counts) and per-pattern planet lists — saves ~15k tokens on a typical chart, useful when you only need placements + angles. Next step: if you need aspect-by-aspect narrative material, call with detail="full"; for transits to this chart, call current_transits or transit_search with the same birth data.. It is categorised as a Read tool in the Celestine MCP Server, which means it retrieves data without modifying state.
Register the Celestine MCP server in PolicyLayer and add a rule for birth_chart: 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 Celestine. Nothing to install.
birth_chart 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 birth_chart 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 birth_chart. 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.
birth_chart is provided by the Celestine MCP server (bouch/celestine). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 12 Celestine tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.