Replace the hand-rolled make([]byte, 0, 1024) + make([]byte, 4096) read loop in WebhookServer.ServeHTTP with a sync.Pool-backed bytes.Buffer drained via ReadFrom, fronted by http.MaxBytesReader for the 1 MiB body cap.
putWebhookBuf caps Cap() at 256 KiB before returning to the pool so a rare oversized update (max body is 1 MiB) doesn't permanently bloat the pool.
Bench delta on Webhook_ServeHTTP: 2564ns -> 2020ns (-21%), 12707B -> 7648B (-40%), 24 -> 23 allocs. The big byte saving is the 4 KiB tmp buffer + 1 KiB initial buf cap, replaced by one reused buffer across requests. The remaining alloc count is dominated by codec.Unmarshal decoding Update's pointer fields (*string, *int64), which is downstream of this change.
Hermetic benchmarks (no network) covering Call encode+decode, webhook ServeHTTP body parse, and Router dispatch (command/regex/filter). Use Go 1.24+ b.Loop() idiom. .benchstats/baseline.txt pins the pre-optimisation numbers for benchstat comparisons.
Both SetWebhookParams.AllowedUpdates and GetUpdatesParams.AllowedUpdates
(plus the WebhookInfo.AllowedUpdates field on the response side) were
typed []string, forcing callers to cast every typed constant:
AllowedUpdates: []string{
string(api.UpdateMessage),
string(api.UpdateMyChatMember),
...
}
Switch to []UpdateType so the same call site is typo-safe end-to-end:
AllowedUpdates: []UpdateType{
api.UpdateMessage,
api.UpdateMyChatMember,
...
}
Wire format is unchanged — UpdateType is type UpdateType string, marshals
identically as JSON strings. The MultipartFields()/runtime.go encoding
paths likewise continue to work via json.Marshal on the typed slice.
Implementation note: api/methods.gen.go and api/types.gen.go are
generated by cmd/genapi from internal/spec/api.json, where the field is
described as Array of String. The Telegram docs do not enumerate the
allowed_updates values inline, so the scraper cannot synthesise the
enum and UpdateType lives hand-curated in api/enums.go (see existing
doc comment there). The retype is therefore done as a small pinned
override inside cmd/genapi/emitter.go's goField — keyed on the wire
field name allowed_updates with elem type string — so the change
survives a future regeneration of the .gen.go files. transport/longpoll
drops the now-unnecessary []string conversion.
Backward incompatibility: callers passing untyped []string variables
will need to convert; callers using untyped string literals inside the
slice ARE fine because Go's untyped-literal rule auto-converts.
A fully-generated, strongly-typed Go client for the Telegram Bot API.
* 176 methods + 301 types generated from Bot API v10.0
* 1408 auto-generated tests (8 scenarios per method)
* Typed unions throughout — no 'any' in the public surface
* Pluggable HTTP transport and JSON codec (default goccy/go-json)
* Built-in retry middleware honouring Telegram's retry_after
* Generic dispatcher with filters and conversation handlers
* Self-verifying codegen pipeline (regen → audit → emit → run tests)
* 14 example bots covering common patterns
lukaszraczylo