Routing

Route syntax is the WHATWG URLPattern standard — the same patterns that work in new URLPattern() in browsers, Node, Deno, Bun, and Cloudflare Workers. hayate does not invent a routing DSL.

@app.get("/books/:id")            # named parameter
@app.get(r"/books/:id(\d+)")      # with a regexp constraint
@app.get("/files/*")              # wildcard -> c.req.param("0")
@app.get("/posts/:slug?")         # optional (also matches /posts)
@app.on("PURGE", "/cache/:key")   # any method

Parameters are percent-decoded:

@app.get("/items/:name")
async def item(c):
    c.req.param("name")   # "あ" for /items/%E3%81%82
    c.req.params          # all parameters as a dict

Query strings ride on the WHATWG URLSearchParams model:

@app.get("/search")
async def search(c):
    c.req.query("q")       # first value or None
    c.req.queries("tag")   # all values
    c.req.url.search_params  # the full URLSearchParams

Matching rules

• Static paths always win over dynamic patterns, regardless of registration order; dynamic patterns match in registration order.
• A path that matches another method's route answers 405 with Allow; no route at all answers 404 (both as RFC 9457 problem documents).
• HEAD falls back to the GET handler; the adapter strips the body and keeps Content-Length.

The documented subset

The v0 series implements the URLPattern pathname component with :name, :name(regexp), anonymous (regexp) groups, the ? modifier, and * wildcards. {} groups and +/* modifiers are rejected loudly at registration time (ValueError), never silently misrouted. Regexp groups are interpreted by Python's re. Conformance against the wpt vectors is measured on every test run — see Conformance.