estimate_capability

Get cost estimates for API capabilities before execution to plan budgets and optimize workflows in AI agent development.

Instructions

Get cost estimate for executing a capability without actually executing it. Use before expensive operations or when building cost-aware workflows.

Input Schema

TableJSON Schema

Name	Required	Description
`capability_id`	Yes	Capability to estimate cost for (e.g. 'email.send')
`provider`	No	Optional: specific provider. If omitted, estimates for the auto-selected provider.
`credential_mode`	No	Credential mode: byo (default), rhumb_managed, or agent_vault

Implementation Reference

packages/mcp/src/tools/estimate.ts:12-22 (handler)

The tool handler function for `estimate_capability`. It takes the validated input and calls the Rhumb API client's `estimateCapability` method.

export async function handleEstimateCapability(
  input: EstimateCapabilityInput,
  client: RhumbApiClient
): Promise<EstimateCapabilityOutput> {
  const result = await client.estimateCapability(input.capability_id, {
    provider: input.provider,
    credentialMode: input.credential_mode
  });

  return result;
}

packages/mcp/src/types.ts:248-256 (schema)

The JSON schema definition for the `estimate_capability` tool input.

export const EstimateCapabilityInputSchema = {
  type: "object" as const,
  properties: {
    capability_id: { type: "string" as const, description: "Capability to estimate (e.g. 'email.send'). Call this BEFORE execute_capability to know the cost in advance." },
    provider: { type: "string" as const, description: "Specific provider slug. Omit to estimate for the auto-selected provider based on your routing strategy." },
    credential_mode: { type: "string" as const, description: "'auto' (default: use Rhumb Resolve when an active managed config exists, otherwise fall back to byo), 'rhumb_managed', 'byo' (BYOK), or 'agent_vault'. Affects pricing — rhumb_managed includes a 20% markup." }
  },
  required: ["capability_id"] as const
};

packages/mcp/src/server.ts:176-186 (registration)

Registration of the `estimate_capability` tool in the MCP server, including input definition and handler invocation. (Note: excerpt is reconstructed based on the pattern found in file).

// -- estimate_capability -----------------------------------------------
server.tool(
  "estimate_capability",
  "Get the cost of a Capability call WITHOUT making the call. Returns cost in USD, circuit health, and endpoint pattern. Default credential mode is auto: Rhumb uses Rhumb Resolve when an active managed config exists, otherwise falls back to byo (BYOK). Always call this before execute_capability for cost-sensitive workflows — no charge for estimates.",
  {
    capability_id: z.string().describe(EstimateCapabilityInputSchema.properties.capability_id.description),
    provider: z.string().optional().describe(EstimateCapabilityInputSchema.properties.provider.description),
    credential_mode: z.string().optional().describe(EstimateCapabilityInputSchema.properties.credential_mode.description)
  },
  async ({ capability_id, provider, credential_mode }) => {
    const result = await handleEstimateCapability(

Rhumb