lwtversion Documentation on ocaml.org
Promises and event-driven I/O
A promise is a value that may become determined in the future.
Lwt provides typed, composable promises. Promises that are resolved by I/O are resolved by Lwt in parallel.
Meanwhile, OCaml code, including code creating and waiting on promises, runs in a single thread by default. This reduces the need for locks or other synchronization primitives. Code can be run in parallel on an opt-in basis.
| Authors | Jérôme Vouillon and Jérémie Dimino | 
|---|---|
| License | MIT | 
| Published | |
| Homepage | https://github.com/ocsigen/lwt | 
| Issue Tracker | https://github.com/ocsigen/lwt/issues | 
| Maintainers | Raphaël Proust <code@bnwr.net> and Anton Bachin <antonbachin@yahoo.com> | 
| Dependencies | 
  | 
| Optional dependencies | |
| Source [http] | https://github.com/ocsigen/lwt/archive/5.6.1.tar.gz md5=279024789a0ec84a9d97d98bad847f97 sha512=698875bd3bfcd5baa47eb48e412f442d289f9972421321541860ebe110b9af1949c3fbc253768495726ec547fe4ba25483cd97ff39bc668496fba95b2ed9edd8  | 
| Edit | https://github.com/ocaml/opam-repository/tree/master/packages/lwt/lwt.5.6.1/opam | 
Required by
- 0install>=2.15.1
 - aches-lwt
 - activitypub
 - albatross
 - alcotest-lwt
 - alcotest-mirage
 - ambient-context-lwt
 - amqp-clientwith-test & >=1.1.0
 - amqp-client-lwt
 - angstrom-lwt-unix>=0.11.0
 - anthill
 - anycache-lwt
 - archi-lwt
 - arp
 - awa-mirage
 - aws-lwt
 - aws-s3-lwt
 - awsm-lwt
 - azure-cosmos-db
 - balancer
 - bastet_lwt
 - bimage-lwt
 - bistro
 - brisk-reconcilerwith-dev-setup
 - brozipbuild
 - builder
 - builder-web<0.2.0
 - bun>=0.3.3
 - cachet-lwt
 - calculon
 - caldav
 - camltc
 - canary
 - capnp-rpc-lwt<2.0
 - capnp-rpc-unix<2.1
 - caqti-lwt
 - caqti-mirage
 - cartonwith-test & <1.0.0
 - carton-git<0.7.2
 - carton-lwt
 - catala-formatwith-test & >=0.2.0
 - cf-lwt
 - chamelon
 - chamelon-unix
 - chamo
 - charrua-client
 - charrua-unix
 - chess_com_api
 - clz
 - cmdtui-lambda-term
 - cohttp-curl-lwt
 - cohttp-lwt<6.0.0
 - cohttp-lwt-jsoo!=6.1.0
 - cohttp-lwt-unix
 - cohttp-mirage
 - cohttp-server-lwt-unix
 - comby
 - comby-semantic
 - conan-lwt
 - conduit-lwt<7.0.0
 - conduit-lwt-unix<7.0.0
 - cowabloga
 - crunchwith-test
 - cstruct-lwt
 - csv-lwt
 - ctypeswith-test & >=0.15.0 & <0.21.1
 - ctypes-foreignwith-test & >=0.21.1
 - curl_lwt
 - current<0.7.1
 - current-albatross-deployer
 - current_docker<0.7.1
 - current_examples<0.7.1
 - current_git<0.7.1
 - current_github<0.7.1
 - current_gitlab<0.7.1
 - current_ocluster
 - current_rpc<0.7.1
 - current_slack<0.7.1
 - current_web<0.7.1
 - DkSDKFFIOCaml_Std
 - dap
 - data-encoding<0.1.1
 - devkit>=1.2
 - distributed-lwt
 - dkim-bin<0.8.0
 - dkim-lwt-unix
 - dkim-mirage
 - dlm
 - dns-certify
 - dns-cli
 - dns-client<7.0.3
 - dns-client-lwt
 - dns-client-mirage
 - dns-forward
 - dns-forward-lwt-unix
 - dns-lwt
 - dns-mirage
 - dns-resolver
 - dns-server
 - dns-stub
 - dnssd
 - docker_hub
 - docteur>=0.0.2
 - docteur-solo5
 - docteur-unix>=0.0.5
 - doi2bib
 - dream
 - dream-httpaf
 - dream-pure
 - dream-serve
 - dropbox
 - dunewith-dev-setup & >=3.17.2
 - dune-rpc-lwt
 - earlybird
 - elasticsearch-cli
 - emojiwith-test & =2.0.0
 - equinoxe
 - ethernet
 - ez_api>=1.2.0
 - ezcurl-lwt
 - ezjs_min<0.2
 - ezjsonm-lwt
 - ezrestowith-test
 - ezresto-directory>=0.5
 - faraday-lwt
 - faraday-lwt-unix
 - fat-filesystem
 - fiber-lwt
 - fsevents-lwt
 - fswatch_lwt
 - fuseau-lwt
 - gdbprofiler
 - git
 - git-cohttp
 - git-cohttp-unix
 - git-mirage
 - git-paf
 - git-unix>=3.2.0
 - github
 - github-hooks
 - github-unix>=4.4.0
 - gitlab-unix
 - gitlab_pipeline_notifier
 - gluten-lwt
 - gluten-lwt-unix<0.4.0
 - gluten-mirage<0.4.0
 - graphql-lwt
 - gremlin
 - grpc-lwt
 - guardian
 - gufo
 - h1with-test
 - h1-lwt-unix
 - h2-lwt
 - h2-lwt-unix<0.10.0
 - h2-mirage
 - happy-eyeballs-lwt
 - happy-eyeballs-mirage
 - hiredis>=0.6
 - hl_yamlwith-test
 - hockmd
 - http-lwt-client
 - http-mirage-client
 - http-multipart-formdata>=2.0.0 & <3.0.0
 - httpaf-lwt-unix
 - httpun-lwt
 - httpun-mirage
 - httpun-ws-lwt
 - hvsock
 - i3ipc
 - influxdb-lwt
 - inotifywith-test & >=2.4
 - inquire<0.3.0
 - interface-prime-lwt
 - ip2location
 - ip2locationio
 - ip2whois
 - ipv6-multicast-lwt
 - irc-client-lwt
 - irc-client-lwt-ssl
 - irc-client-tls
 - irmin
 - irmin-bench
 - irmin-chunk
 - irmin-cli
 - irmin-containers
 - irmin-fs
 - irmin-git
 - irmin-graphql
 - irmin-http
 - irmin-indexeddb
 - irmin-layers
 - irmin-mirage-git
 - irmin-mirage-graphql
 - irmin-pack
 - irmin-server
 - irmin-test
 - irmin-unix
 - irmin-watcher
 - joolog
 - josewith-test & <0.9.0
 - js_of_ocaml-lwt>=3.5.0
 - jsoo_broadcastchannel
 - jsoo_storage
 - jupyter
 - jupyter-kernel
 - kafka<0.5
 - kafka_lwt
 - kappa-library
 - kewith-test & >=0.5
 - kinetic-client
 - kubecaml
 - lambda-runtime
 - lambda-term
 - lambda_streams_lwt
 - launchd
 - ldp
 - learn-ocaml
 - learn-ocaml-client
 - letsencrypt
 - letsencrypt-app
 - letsencrypt-dns
 - letters
 - lichess_api
 - links>=0.9.1
 - linol-lwt
 - llama
 - lru_cachewith-test
 - lwt-canceler
 - lwt-dllistwith-test
 - lwt-exit
 - lwt-parallel
 - lwt-pipe
 - lwt-pipeline
 - lwt-watcher
 - lwt_camlp4
 - lwt_domain
 - lwt_eio<0.4
 - lwt_glib
 - lwt_log
 - lwt_ppx<5.8.0
 - lwt_react
 - lwt_retry
 - lwt_ssl
 - mariadbwith-test & >=1.2.0
 - markupwith-test & =0.7.6
 - markup-lwt
 - mdxwith-test
 - mechaml
 - mehari-lwt-unix
 - mehari-mirage
 - memtrace-mirage
 - metrics-influx
 - metrics-lwt
 - metrics-unix
 - mimic
 - mindstorm-lwt
 - mirage<4.0.0
 - mirage-block>=2.0.1
 - mirage-block-ccm
 - mirage-block-combinators
 - mirage-block-lwt
 - mirage-block-partition
 - mirage-block-ramdisk
 - mirage-block-solo5
 - mirage-block-unikraft
 - mirage-block-unix>=2.14.2
 - mirage-block-xen
 - mirage-channel>=4.0.1
 - mirage-channel-lwt
 - mirage-clock-lwt
 - mirage-clock-unix<4.2.0
 - mirage-console-lwt
 - mirage-crypto-rng<0.11.3
 - mirage-crypto-rng-lwt
 - mirage-crypto-rng-mirage
 - mirage-device>=2.0.0
 - mirage-flow>=3.0.0
 - mirage-flow-combinators
 - mirage-flow-lwt
 - mirage-flow-unix
 - mirage-fs>=4.0.0
 - mirage-fs-lwt
 - mirage-kv>=3.0.1
 - mirage-kv-lwt
 - mirage-kv-unix<3.0.1
 - mirage-net>=4.0.0
 - mirage-net-lwt
 - mirage-net-macosx
 - mirage-net-solo5
 - mirage-net-unikraft
 - mirage-net-unix
 - mirage-net-xen
 - mirage-profile
 - mirage-protocols>=7.0.0
 - mirage-protocols-lwt
 - mirage-runtime
 - mirage-sleep
 - mirage-solo5
 - mirage-stack=3.0.0
 - mirage-stack-lwt
 - mirage-time>=3.0.0
 - mirage-time-lwt
 - mirage-time-unix
 - mirage-types-lwt
 - mirage-unikraft
 - mirage-unix
 - mirage-vnetif
 - mirage-xen
 - monorobot
 - moonpool-lwt
 - mrmimewith-test & >=0.5.0
 - multipart-form-data
 - multipart_form>=0.2.0 & <0.4.0
 - multipart_form-cohttp-lwt<0.6.0
 - multipart_form-lwt
 - mwt
 - naboris
 - nbd>=4.0.3
 - nbd-tool
 - nbd-unix
 - nocrypto
 - nottui-lwt
 - notty-communitywith-test
 - nproc
 - nsq
 - obuilder
 - obus>=1.2.1
 - ocluster
 - ocluster-api
 - ocluster-worker
 - ocplib-resto
 - ocsigen-start>=4.1.0 & <4.7.0
 - ocsigenserver
 - ocsipersist
 - ocsipersist-dbm
 - ocsipersist-lib
 - ocsipersist-pgsql
 - ocsipersist-sqlite
 - octez-distributed-lwt-internal<19.0
 - octez-l2-libs<19.0
 - octez-libs<19.0
 - octez-proto-libswith-test & <19.0
 - octez-protocol-compiler<19.0
 - octez-proxy-server<19.0
 - octez-shell-libswith-test & <19.0
 - octez-smart-rollup-wasm-benchmark-lib
 - oframl
 - ojs-base
 - ojs_base
 - omigrate
 - oneffs
 - opam-compiler<0.2.0
 - opencage
 - opentelemetry-client-cohttp-lwt
 - opentelemetry-cohttp-lwt>=0.4
 - opentelemetry-lwt
 - opium
 - opium-graphql
 - opium_kernel
 - opomodoro
 - order-i3-xfce
 - ordma
 - oskel>=0.3.0
 - ounit-lwt<2.2.0
 - ounit2-lwt
 - owork
 - ozulip
 - pafwith-test
 - paf-cohttpwith-test
 - passage<0.1.8
 - pcap-formatwith-test & <0.5.2
 - petrol
 - pgn_parser
 - pgx_lwt
 - pgx_lwt_mirage
 - pgx_lwt_unix<2.0
 - piaf<0.2.0
 - plebeia>=2.0.0
 - plist-xml-lwt
 - plotkicadsch
 - ppx_deferwith-test & >=0.4.0
 - ppx_deriving_rpcwith-test
 - ppx_rapper_lwt
 - proc-smaps
 - prof_spacetime
 - prometheus
 - prometheus-app
 - promise_jsoo_lwt
 - protocol-9p
 - protocol-9p-unix
 - proton
 - qcow
 - qcow-stream
 - qcow-tool
 - qcow-types
 - qfs>=0.5
 - quests
 - rawlink<2.1
 - rawlink-lwt
 - rdf_json_ld<1.0.0
 - rdf_lwt<1.0.0
 - redis-lwt
 - reparse-lwt
 - reparse-lwt-unix
 - resource-pooling
 - resp
 - resp-mirage>=0.10.0
 - resp-unix>=0.10.0
 - restowith-test
 - resto-cohttp-client>=0.4
 - resto-cohttp-self-serving-client
 - resto-cohttp-server>=0.4 & <0.6 | >=0.9
 - resto-directory>=0.4
 - riak
 - ringo-lwt
 - river
 - rock
 - rpclib-js
 - rpclib-lwt
 - SZXX<4.0.0
 - sanddb
 - scgi
 - sendmail-lwt
 - sendmail-mirage
 - serial
 - server-reason-react
 - session-cohttp-lwt
 - session-cookie-lwt
 - session-postgresql-lwt
 - sessions
 - shared-block-ring
 - shared-memory-ring-lwt
 - sihl<0.2.0
 - slack
 - slacko
 - slipshow
 - smtmlwith-dev-setup & >=0.7.0
 - speed
 - spin<0.8.0
 - spoke
 - stk
 - stog<1.0.0
 - syguslib-utils
 - syndicwith-test & >=1.4 & <1.6.0
 - tar-mirage
 - tar-unix<3.3.0
 - tcpip
 - telegraml
 - terminus
 - testo-lwt
 - tezos-base>=16.0
 - tezos-clic>=16.0
 - tezos-crypto>=16.0
 - tezos-crypto-dal
 - tezos-error-monad>=16.0
 - tezos-lwt-result-stdlib
 - tezos-p2p=12.3
 - tezos-protocol-environmentwith-test
 - tezos-proxywith-test & >=17.3
 - tezos-stdlib
 - tezos-stdlib-unix>=16.0
 - tezos-test-helpers>=12.3
 - tezos-wasmer
 - tezos-webassembly-interpreter-extra
 - tezt
 - tidy_email
 - timmy-lwt
 - tls>=0.10.6 & <0.16.0
 - tls-lwt<0.17.5
 - tls-mirage
 - tube
 - tuntapwith-test
 - twirp_cohttp_lwt_unix
 - uringwith-test
 - uspf
 - uspf-lwt
 - uspf-mirage
 - utop
 - uwt
 - vchan
 - vchan-unix
 - vchan-xen
 - vercel
 - vhd-format-lwt
 - vmnet
 - vpnkit
 - vue-jsoo<0.3
 - wayland<2.0
 - webauthndev
 - xen-evtchn
 - xen-evtchn-unix
 - xen-gnt
 - xen-gnt-unix
 - xenstore
 - xenstore-tool
 - xenstore_transport
 - xlsx2csv
 - yocaml_git<2.0.0
 - yocaml_unix<2.0.0
 - zarr-lwt
 - zmq-lwt
 
Optionally used by
- amqp-client<2.0.0
 - anycache<0.7.4
 - aws<1.2
 - biocaml
 - bookaml
 - coq-lsp>=0.1.9+8.17
 - csv=1.6
 - debian-formats<0.1.2
 - exenum
 - ezjs_extension
 - ezjs_fetch>=0.2
 - ezjs_min>=0.2
 - faraday<0.3.0
 - hxd>=0.3.0
 - inotify
 - irc-client<0.6.0
 - logs
 - logs-syslog
 - markup<0.8.0
 - mirage-types<3.6.0
 - notty
 - notty-community
 - ocurl<transition
 - opentelemetry>=0.11
 - osc<0.2.0
 - osx-acl
 - osx-attr
 - osx-cf
 - osx-fsevents
 - osx-membership
 - osx-mount
 - osx-xattr
 - raygun4ocaml
 - rdf<0.13.0
 - sendmsg
 - session<0.4.0
 - shcaml
 - smtp
 - unix-dirent
 - unix-sys-stat>=0.4.0
 - unix-unistd
 
          

