package lwt

  1. Overview
  2. No Docs
Promises and event-driven I/O

Install 

dune-project
 Dependency

github.com Edit opam file Versions (32)

Authors

  1. J
    Jérôme Vouillon
  2. J
    Jérémie Dimino

Maintainers

  1. R
    Raphaël Proust <code@bnwr.net>
  2. Anton Bachin

Sources

6.1.2.tar.gz
md5=00bc7eb2772a28530f7365a7040f0c4f
sha512=a4737a2fc44aaeedca46ec6134c07013d5cf44039a988a6e79a40715a53e43601d4c91bbf11a8e89540528d912b8fa487e3068465c136c1156a872258eb3443b

Description

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.

Published: 29 Apr 2026

Dependencies (5)

  1. ocplib-endian
  2. dune-configurator
  3. cppo build & >= "1.1"
  4. ocaml >= "4.14"
  5. dune >= "3.18"

Dev Dependencies (2)

  1. odoc with-doc & >= "2.3"
  2. ocamlfind dev & >= "1.7.3-1"

  1. 0install >= "2.15.1"
  2. aches-lwt
  3. activitypub
  4. albatross
  5. alcotest-lwt
  6. alcotest-mirage
  7. ambient-context-lwt
  8. amqp-client >= "1.1.0"
  9. amqp-client-lwt
  10. angstrom-lwt-unix >= "0.11.0"
  11. anthill
  12. anycache-lwt
  13. archi-lwt
  14. arp
  15. awa-mirage
  16. aws-lwt
  17. aws-s3-lwt < "4.4.0" | >= "4.8.1"
  18. awsm-lwt
  19. azure-cosmos-db < "0.4.0"
  20. azure-cosmos-db-lwt
  21. balancer
  22. bastet_lwt
  23. bistro
  24. brisk-reconciler
  25. brozip
  26. builder
  27. builder-web
  28. bun >= "0.3.3"
  29. cachet-lwt
  30. calculon
  31. caldav
  32. camltc
  33. canary
  34. capnp-rpc-lwt < "2.0"
  35. capnp-rpc-unix < "2.1"
  36. caqti-mirage
  37. carton < "1.0.0"
  38. carton-git
  39. carton-lwt
  40. catala-format >= "0.2.0"
  41. cf-lwt
  42. chamelon
  43. chamelon-unix
  44. chamo
  45. charrua-client
  46. charrua-unix
  47. chess_com_api
  48. ciao_lwt
  49. clz
  50. cmdtui-lambda-term
  51. coap
  52. coap-server-lwt
  53. cohttp-curl-lwt
  54. cohttp-lwt
  55. cohttp-lwt-jsoo
  56. cohttp-lwt-unix
  57. cohttp-mirage
  58. cohttp-server-lwt-unix
  59. comby
  60. comby-semantic
  61. conan-lwt
  62. conduit-lwt
  63. conduit-lwt-unix
  64. cowabloga
  65. crunch
  66. cstruct-lwt
  67. csv-lwt
  68. ctypes >= "0.15.0" & < "0.21.1"
  69. ctypes-foreign >= "0.21.1"
  70. curl_lwt
  71. current
  72. current-albatross-deployer
  73. current_docker
  74. current_examples
  75. current_git
  76. current_github
  77. current_gitlab
  78. current_ocluster
  79. current_rpc
  80. current_slack
  81. current_web
  82. dap
  83. data-encoding < "0.1.1"
  84. devkit >= "1.2"
  85. distributed-lwt
  86. dkim-bin < "0.8.0"
  87. dkim-lwt-unix
  88. dkim-mirage
  89. dlm
  90. dmarc
  91. dns-certify
  92. dns-cli
  93. dns-client < "7.0.3"
  94. dns-client-lwt
  95. dns-client-mirage
  96. dns-forward
  97. dns-forward-lwt-unix
  98. dns-lwt
  99. dns-mirage
  100. dns-resolver
  101. dns-server
  102. dns-stub
  103. dnsrobot
  104. dnssd
  105. docker_hub
  106. docteur >= "0.0.2"
  107. docteur-solo5
  108. docteur-unix >= "0.0.5"
  109. doi2bib
  110. dream
  111. dream-httpaf
  112. dream-pure
  113. dream-serve
  114. dropbox
  115. dune >= "3.17.2"
  116. dune-rpc-lwt
  117. earlybird
  118. elasticsearch-cli
  119. emoji = "2.0.0"
  120. equinoxe
  121. ethernet
  122. ez_api >= "1.2.0"
  123. ezcurl-lwt
  124. ezjs_min < "0.2"
  125. ezjsonm-lwt
  126. ezresto
  127. faraday-lwt
  128. faraday-lwt-unix
  129. fat-filesystem
  130. fiber-lwt
  131. fsevents-lwt
  132. fswatch_lwt
  133. gdbprofiler
  134. git
  135. git-cohttp
  136. git-cohttp-unix
  137. git-kv >= "0.2.0"
  138. git-mirage
  139. git-paf
  140. git-unix >= "3.2.0"
  141. github
  142. github-hooks
  143. github-unix >= "4.4.0"
  144. gitlab-unix
  145. gitlab_pipeline_notifier
  146. gluten-lwt
  147. gluten-lwt-unix < "0.4.0"
  148. gluten-mirage < "0.4.0"
  149. graphql-lwt
  150. gremlin
  151. grpc-lwt
  152. guardian
  153. gufo
  154. h1
  155. h1-lwt-unix
  156. h2-lwt
  157. h2-lwt-unix < "0.10.0"
  158. h2-mirage
  159. happy-eyeballs-lwt
  160. happy-eyeballs-mirage
  161. hidapi-lwt
  162. hiredis >= "0.6"
  163. hl_yaml
  164. hockmd
  165. http-lwt-client
  166. http-mirage-client
  167. http-multipart-formdata >= "2.0.0" & < "3.0.0"
  168. httpaf-lwt-unix
  169. httpun-lwt
  170. httpun-mirage
  171. httpun-ws-lwt
  172. hvsock
  173. i3ipc
  174. influxdb-lwt
  175. inotify >= "2.4"
  176. inquire < "0.3.0"
  177. interface-prime-lwt
  178. ip2location
  179. ip2locationio
  180. ip2whois
  181. ipv6-multicast-lwt
  182. irc-client-lwt
  183. irc-client-lwt-ssl
  184. irc-client-tls
  185. irmin
  186. irmin-bench
  187. irmin-chunk
  188. irmin-cli
  189. irmin-client
  190. irmin-containers
  191. irmin-fs
  192. irmin-git
  193. irmin-graphql
  194. irmin-http
  195. irmin-indexeddb
  196. irmin-layers
  197. irmin-mirage-git
  198. irmin-mirage-graphql
  199. irmin-pack
  200. irmin-server
  201. irmin-test
  202. irmin-unix
  203. irmin-watcher
  204. joolog
  205. jose < "0.9.0"
  206. js_of_ocaml-lwt >= "3.5.0"
  207. jsoo_broadcastchannel
  208. jsoo_storage
  209. jupyter
  210. jupyter-kernel
  211. kafka < "0.5"
  212. kafka_lwt
  213. kappa-library
  214. ke >= "0.5"
  215. kinetic-client
  216. kubecaml
  217. lambda-runtime
  218. lambda-term >= "3.3.3"
  219. lambda_streams_lwt
  220. launchd
  221. ldp
  222. learn-ocaml
  223. learn-ocaml-client
  224. ledgerwallet >= "0.4.0"
  225. letsencrypt < "2.0.0"
  226. letsencrypt-app
  227. letsencrypt-dns < "2.0.0"
  228. letters
  229. lichess_api
  230. links >= "0.9.1"
  231. llama
  232. lru_cache
  233. lwt-canceler
  234. lwt-dllist
  235. lwt-exit
  236. lwt-parallel
  237. lwt-pipe
  238. lwt-pipeline
  239. lwt-watcher
  240. lwt_camlp4
  241. lwt_direct >= "6.0.0"
  242. lwt_eio >= "0.6"
  243. lwt_ppx >= "6.0.0"
  244. lwt_react
  245. lwt_retry
  246. lwt_ssl
  247. mariadb >= "1.2.0"
  248. markdown_monolith
  249. markup = "0.7.6"
  250. markup-lwt
  251. mdx
  252. mechaml
  253. mehari-lwt-unix
  254. mehari-mirage
  255. memtrace-mirage
  256. metrics-influx
  257. metrics-lwt
  258. metrics-unix
  259. mimic
  260. mindstorm-lwt
  261. mirage < "4.0.0"
  262. mirage-block >= "2.0.1"
  263. mirage-block-ccm
  264. mirage-block-combinators
  265. mirage-block-lwt
  266. mirage-block-partition
  267. mirage-block-ramdisk
  268. mirage-block-solo5
  269. mirage-block-unikraft
  270. mirage-block-unix >= "2.14.2"
  271. mirage-block-xen
  272. mirage-channel >= "4.0.1"
  273. mirage-channel-lwt
  274. mirage-clock-lwt
  275. mirage-clock-unix < "4.2.0"
  276. mirage-console-lwt
  277. mirage-crypto-rng < "0.11.3"
  278. mirage-crypto-rng-lwt
  279. mirage-crypto-rng-mirage
  280. mirage-device >= "2.0.0"
  281. mirage-flow >= "3.0.0"
  282. mirage-flow-combinators
  283. mirage-flow-lwt
  284. mirage-flow-unix
  285. mirage-fs >= "4.0.0"
  286. mirage-fs-lwt
  287. mirage-kv >= "3.0.1"
  288. mirage-kv-lwt
  289. mirage-kv-unix
  290. mirage-net >= "4.0.0"
  291. mirage-net-lwt
  292. mirage-net-macosx
  293. mirage-net-solo5
  294. mirage-net-unikraft
  295. mirage-net-unix
  296. mirage-net-xen
  297. mirage-profile
  298. mirage-protocols >= "7.0.0"
  299. mirage-protocols-lwt
  300. mirage-qubes
  301. mirage-qubes-ipv4
  302. mirage-runtime
  303. mirage-sleep
  304. mirage-solo5
  305. mirage-stack = "3.0.0"
  306. mirage-stack-lwt
  307. mirage-time >= "3.0.0"
  308. mirage-time-lwt
  309. mirage-time-unix
  310. mirage-types-lwt
  311. mirage-unikraft
  312. mirage-unix
  313. mirage-vnetif
  314. mirage-xen
  315. monorobot
  316. mqtt
  317. mrmime >= "0.5.0"
  318. multipart-form-data
  319. multipart_form >= "0.2.0" & < "0.4.0"
  320. multipart_form-cohttp-lwt < "0.6.0"
  321. multipart_form-lwt
  322. naboris
  323. nbd >= "4.0.3"
  324. nbd-tool
  325. nbd-unix
  326. neo4j_bolt
  327. nottui-lwt
  328. notty-community
  329. nproc
  330. nsq
  331. obuilder
  332. obus >= "1.2.1"
  333. ocaml-ai-sdk
  334. ocluster-api
  335. ocluster-worker
  336. ocplib-resto
  337. ocsigenserver
  338. ocsipersist
  339. ocsipersist-dbm
  340. ocsipersist-lib
  341. ocsipersist-pgsql
  342. ocsipersist-sqlite
  343. oframl
  344. ojs_base
  345. omigrate
  346. oneffs
  347. opam-check-npm-deps >= "4.1.0"
  348. opam-publish >= "3.0.0"
  349. opencage
  350. opentelemetry-client-cohttp-lwt
  351. opentelemetry-client-ocurl-lwt
  352. opentelemetry-cohttp-lwt >= "0.4"
  353. opentelemetry-lwt
  354. opium
  355. opium-graphql
  356. opium_kernel
  357. opomodoro
  358. order-i3-xfce
  359. ordma
  360. oskel >= "0.3.0"
  361. ounit-lwt < "2.2.0"
  362. ounit2-lwt
  363. owork
  364. ozulip
  365. paf
  366. paf-cohttp
  367. passage < "0.1.8"
  368. pcap-format < "0.5.2"
  369. petrol
  370. pgn_parser
  371. pgx_lwt
  372. pgx_lwt_mirage
  373. pgx_lwt_unix < "2.0"
  374. piaf < "0.2.0"
  375. picos_meta
  376. plebeia >= "2.0.0"
  377. plotkicadsch
  378. posix-getopt >= "4.0.2"
  379. ppx_defer >= "0.4.0"
  380. ppx_deriving_rpc
  381. ppx_rapper_lwt
  382. proc-smaps
  383. prof_spacetime
  384. prometheus
  385. prometheus-app
  386. promise_jsoo_lwt
  387. protocol-9p
  388. protocol-9p-unix
  389. proton
  390. pxshot
  391. qcow
  392. qcow-stream
  393. qcow-tool
  394. qcow-types
  395. qdrant < "0.2.0"
  396. qfs >= "0.5"
  397. quests
  398. quickterface
  399. rawlink < "2.1"
  400. rawlink-lwt
  401. rdf_json_ld
  402. rdf_lwt
  403. redis-lwt
  404. reparse-lwt
  405. reparse-lwt-unix
  406. resource-pooling
  407. resp
  408. resp-mirage >= "0.10.0"
  409. resp-unix >= "0.10.0"
  410. resto
  411. resto-cohttp-client = "0.4"
  412. resto-cohttp-server = "0.4"
  413. resto-directory = "0.4"
  414. riak
  415. ringo-lwt
  416. river
  417. rock
  418. rpclib-js
  419. rpclib-lwt
  420. SZXX < "4.0.0"
  421. sanddb
  422. scgi
  423. sendmail-lwt
  424. sendmail-mirage
  425. serial
  426. server-reason-react
  427. session-cohttp-lwt
  428. session-cookie-lwt
  429. session-postgresql-lwt
  430. sessions
  431. shared-block-ring
  432. shared-memory-ring-lwt
  433. sherlodoc
  434. sihl < "0.2.0"
  435. slack
  436. slacko
  437. slipshow
  438. smtml >= "0.7.0"
  439. speed
  440. spin < "0.8.0"
  441. spoke
  442. statocaml
  443. stk
  444. stog
  445. swapfs
  446. syguslib-utils
  447. syndic >= "1.4" & < "1.6.0"
  448. tar-mirage
  449. tar-unix
  450. tcpip
  451. telegraml
  452. terminus
  453. testcontainers
  454. testo-lwt
  455. tidy_email
  456. tls >= "0.10.6" & < "0.16.0"
  457. tls-lwt
  458. tls-mirage
  459. tube
  460. tuntap
  461. twirp_cohttp_lwt_unix
  462. uring
  463. uspf
  464. uspf-lwt
  465. uspf-mirage
  466. utcp
  467. utop
  468. uwt
  469. vchan
  470. vchan-unix
  471. vchan-xen
  472. vercel
  473. vhd-format-lwt
  474. vmnet
  475. vue-jsoo < "0.3"
  476. wayland < "2.0"
  477. webauthn
  478. xen-evtchn
  479. xen-evtchn-unix
  480. xen-gnt
  481. xen-gnt-unix
  482. xenstore
  483. xenstore-tool
  484. xenstore_transport
  485. xlsx2csv
  486. yocaml_git
  487. yocaml_unix < "2.0.0"
  488. zarr-lwt
  489. zmq-lwt >= "5.2.1"

Conflicts

None