example

const (
	// ToolEcho returns its input. It is the cheap, ordinary case.
	ToolEcho = "echo"

	// ToolSlowEcho returns its input after a delay, to show that a reservation
	// is held for the whole of a call rather than taken at its end.
	ToolSlowEcho = "slow_echo"

	// ToolAlwaysFails always reports failure. It demonstrates the billing rule
	// that matters most against an agent: a tool that ran and reported a domain
	// error is billed, so retrying it is not free.
	ToolAlwaysFails = "always_fails"

	// ToolExpensive is priced above the per-tool cap on purpose, so that a
	// misconfigured price is visibly refused before any credit moves.
	ToolExpensive = "expensive"
)

const (
	PriceEcho        metered.Cost = 1
	PriceSlowEcho    metered.Cost = 5
	PriceAlwaysFails metered.Cost = 2
	PriceExpensive   metered.Cost = 500

	// ToolCap is the example's per-tool cap. PriceExpensive is deliberately
	// above it.
	ToolCap metered.Cost = 50

	// SessionCeiling is the example's cumulative per-session ceiling.
	SessionCeiling metered.Cost = 100

	// RateLimit and RateBurst configure the example's token bucket.
	RateLimit float64 = 5
	RateBurst float64 = 10

	// DemoToken is the bearer token the example accepts, and DemoPrincipal the
	// account it maps to. Both are fixtures printed by the server at startup;
	// neither is a credential to anything.
	DemoToken     = "demo-token"
	DemoPrincipal = "demo-account"

	// StartingCredit is how much the demo account is funded with.
	StartingCredit metered.Cost = 60

	// DefaultAddr is the address the example server listens on.
	DefaultAddr = "localhost:8080"

	// MCPPath is the HTTP path the MCP endpoint is served at.
	MCPPath = "/mcp"

	// ServerName and ServerVersion identify the example server to clients.
	ServerName    = "mcp-metered-example"
	ServerVersion = "v0.1.0"

	// SlowEchoDelay is how long ToolSlowEcho takes.
	SlowEchoDelay = 250 * time.Millisecond

	// ShutdownGrace is how long [Run] gives in-flight requests to finish after
	// its context is cancelled.
	ShutdownGrace = 5 * time.Second

	// ReadHeaderTimeout bounds how long a client may take to send its headers.
	ReadHeaderTimeout = 10 * time.Second
)