Pick the right function for every request.

What you can do

• Choose from seven routing strategies, including weighted rollouts and per-rule policies.
• Add a fallback chain so a single function failure never breaks pricing.
• Wrap each candidate in a circuit breaker that opens on errors and recovers automatically.
• Override the policy per request with an explicit function name when you need to.
• Audit which function actually served each call from the Cost Tracing view.

Seven routing strategies

• explicit

  Pin to one function. Useful when a tenant wants exact, repeatable behaviour.

• cheapest

  Lowest expected cost wins. Good for high-volume, latency-tolerant traffic.

• fastest

  Lowest p95 latency wins. Good for checkout and real-time surfaces.

• round_robin

  Even split across candidates. Good for warming a new function.

• weighted

  Per-function weights. Roll out a new model at 5% and ramp it up.

• policy

  Custom rules per request — segment, geo, product type, anything in context.

• default

  The tenant's pinned default with a fallback chain behind it.

The runtime list and the RoutingStrategy type both come from ROUTING_STRATEGIES in packages/pcn, so this page can never drift from what the router actually accepts.

A policy looks like this

{
  "name": "checkout-pricing",
  "strategy": "policy",
  "rules": [
    { "when": { "segment": "enterprise" }, "function": "lastprice/jale-advanced" },
    { "when": { "geo": "EU" },             "function": "lastprice/jale-elasticity" }
  ],
  "fallback_chain": [
    "lastprice/jale-optimizer",
    "lastprice/jale-psychological"
  ]
}