post_v1_tools_call

CallTool runs one of the caller's activated tools and answers with its output.

This is the door onto the tool plane's DYNAMIC half — the half no build-time catalogue can hold, because it is per-tenant: an org's connected connector actions, its authored skills, its agents and functions, and the tools of every external MCP server it registered. A tool's existence, its price and its activation are all rows, not code, so they cannot be known until the caller is.

One policy, the registry's: resolve by precedence, refuse an unactivated tool 403, settle a priced one through the x402 seam or fail closed 402, then dispatch to the winning source bound to the caller's own (org, project). One metered unit, one audit record. A caller can only ever dispatch its own tools.

Discovery is GET /v1/tools — ?activated=true for the callable set.

Arguments

This tool's schema does not declare which fields are required, nor any default, nor any enumerated value set. The columns above are empty because the door publishes nothing there, not because the answer is "none" — where a field is constrained, the constraint is stated in that field's own description.

Call it

A tools/call carries every argument in one flat object — nothing binds to a path or a query string. Every declared argument is shown, because the door marks none of them required.

curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "post_v1_tools_call",
         "arguments": {
           "arguments": {},
           "name": "<name>"
         }
       }
     }'

Values are placeholders derived from each field's declared type. tools/list needs no credential; tools/call does — called without one the door answers HTTP 200 with a JSON-RPC result whose isError is set and whose text says what was missing. How to get a key →

The operation behind it

The same capability over plain HTTP is in the tools API reference, on https://api.hanzo.ai.

All 834 tools · The door · API reference

Generated from tools/list on https://api.hanzo.ai/v1/mcp — 834 tools captured 2026-08-01 (this build read the vendored copy; the door was unreachable).