twine · gleam / otp 26+

webhook fan-out
for the beam.

one inbox, many outboxes. toml-defined routes, otp-supervised dispatch, a tiny sqlite ring for replays, and an sse feed you can curl. i wanted webhookd | tee and kept not finding it, so this is that.

# twine.toml
[server]
port = 8800
db   = "twine.db"

[[route]]
source = "/github"
when_header = "X-GitHub-Event: push"
destinations = [
  "https://hooks.slack.com/services/...",
  "https://ci.local/trigger",
]

[[route]]
source = "/stripe"
retries = 3
secret_header = "X-Hub-Signature-256"
destinations = ["https://ledger.local/stripe"]

live feed

curl the sse stream, watch things happen.

$ curl -N http://localhost:8800/_twine/events

event: dispatch
data: {"id":"01hx...","source":"/github","ok":2,"fail":0,"ms":141}

event: dispatch
data: {"id":"01hx...","source":"/stripe","ok":1,"fail":0,"ms":63}

event: retry
data: {"id":"01hx...","dest":"ci.local","attempt":2,"wait_ms":400}

$ curl -X POST http://localhost:8800/_twine/replay/01hx...
ok

what it does

small, and on purpose.

toml routes in, fanout out.

point any service's webhook at /<something>. twine looks up the route, checks an optional header guard, verifies optional hmac, fires the body at every destination concurrently with backoff. retries are per-destination so one slow endpoint doesn't stall the others.

sqlite replay ring.

every event lands in a ~1000-row ring. replay any stored event with one POST /_twine/replay/:id. the db reaps on insert via offset 1000. on a hot server that's a tiny redundant scan. haven't benchmarked.

otp supervised.

each route has its own worker tree. if a dispatch crashes, supervisor restarts the worker. the http listener stays up. this is the part you get for free by writing it in gleam instead of node.

rough edges

body size capped at 1mb. bigger payloads get a 413.
no auth on /_twine/replay. put it behind something if your twine is public.
the tail subcommand is a stub right now. ask me how i know.
21 tests covering config parsing, routing, sqlite roundtrips, backoff math.

install

$ git clone https://github.com/f4rkh4d/twine
$ cd twine
$ gleam run -- check --config twine.toml
$ gleam run -- serve --config twine.toml