--- source_url: https://www.pubnub.com/docs/sdks/c/changelog title: Changelog for C SDK updated_at: 2026-09-24T12:25:41.000Z sdk_name: PubNub C SDK sdk_version: 1.0.0 --- # Changelog for C SDK PubNub C SDK, use the latest version: 1.0.0 ## Documentation index To discover more PubNub resources: 1. Fetch [PubNub's llms.txt](https://www.pubnub.com/llms-full.txt) for a list of available pages in Markdown format. 2. Identify relevant URLs from that index. 3. Fetch the target pages. Do not assume a path exists, always check the index first. :::note ## 1.0.0 *September 21, 2026* | Type | Changes | |------|----------| | **Added** | • Ground-up rewrite of the PubNub C SDK: a platform-neutral C11 core (with a C99 compatibility mode) built around six pluggable provider families — transport, serialization, crypto, allocator, logger, and platform.
• Multi-context architecture with no static or global per-context state; multiple independent client contexts operate concurrently in a single process.
• Pluggable HTTP transport providers: a libcurl-backed backend for hosted platforms and a native BSD-socket backend for constrained and embedded targets.
• Pluggable allocator providers supporting both a hosted heap-managed model and an embedded no-heap arena model with preallocated per-context/request pools sized for N concurrent in-flight requests.
• Three request-completion styles for every asynchronous operation: blocking await (sync), completion callback (async), and cooperative single-threaded polling via pubnub_process for no-thread event loops.
• Request/future handles with a three-level timeout hierarchy (global, endpoint, per-request), configurable in-flight concurrency, and explicit bounded-queue backpressure.
• Compile-time secure transport (PUBNUB_ENABLE_SECURE_TRANSPORT) with OpenSSL and mbedTLS TLS stacks selectable per transport backend; plaintext requires explicit opt-out.
• Named build profiles (full, minimal, embedded) with per-profile memory and latency budgets, plus explicit CMake feature toggles for every feature module.
• Payload crypto module with an AES-256-CBC cryptor using a random initialization vector (identifier ACRH) and a legacy cryptor, exposed through a pluggable crypto provider contract.
• Publish API: synchronous and asynchronous delivery, GET and POST transport, store flag with per-message TTL, stream-filter metadata, raw JSON value trees, optional body compression, and file-message publishing.
• Subscribe API (event-engine, PubSub v2): channels, channel groups, presence channels, wildcard subscriptions, stream-filter expressions, and timetoken cursor restore, with typed listeners for messages, signals, message actions, files, presence, and App Context objects.
• Presence API: here-now, where-now, get/set presence state, and heartbeat.
• Channel Groups API: add and remove channels, list channels in a group, and remove a group.
• Message Persistence (Storage) API: fetch messages with metadata, message actions, file, message-type and publisher-UUID includes, reverse ordering, count and start/end bounds, delete messages, and message counts.
• Message Actions API: add, get, and remove reactions on published messages.
• Signal API: lightweight signal publishing.
• Files API: send, list, download, delete, generate a file URL, and publish a file message.
• App Context (Objects v2) API: get/set/remove UUID and channel metadata, list all UUID and channel metadata, and manage memberships and channel members.
• Access Manager v3 API: grant, parse, set, and revoke resource tokens.
• Mobile Push API: add, remove, and list channels for a device and remove a device, for the APNS2 and FCM gateways.
• Time API: fetch the current PubNub network timetoken. | ::: ### 1.0.0 September 21, 2026 | Added | Ground-up rewrite of the PubNub C SDK: a platform-neutral C11 core (with a C99 compatibility mode) built around six pluggable provider families — transport, serialization, crypto, allocator, logger, and platform., Multi-context architecture with no static or global per-context state; multiple independent client contexts operate concurrently in a single process., Pluggable HTTP transport providers: a libcurl-backed backend for hosted platforms and a native BSD-socket backend for constrained and embedded targets., Pluggable allocator providers supporting both a hosted heap-managed model and an embedded no-heap arena model with preallocated per-context/request pools sized for N concurrent in-flight requests., Three request-completion styles for every asynchronous operation: blocking await (sync), completion callback (async), and cooperative single-threaded polling via pubnub_process for no-thread event loops., Request/future handles with a three-level timeout hierarchy (global, endpoint, per-request), configurable in-flight concurrency, and explicit bounded-queue backpressure., Compile-time secure transport (PUBNUB_ENABLE_SECURE_TRANSPORT) with OpenSSL and mbedTLS TLS stacks selectable per transport backend; plaintext requires explicit opt-out., Named build profiles (full, minimal, embedded) with per-profile memory and latency budgets, plus explicit CMake feature toggles for every feature module., Payload crypto module with an AES-256-CBC cryptor using a random initialization vector (identifier ACRH) and a legacy cryptor, exposed through a pluggable crypto provider contract., Publish API: synchronous and asynchronous delivery, GET and POST transport, store flag with per-message TTL, stream-filter metadata, raw JSON value trees, optional body compression, and file-message publishing., Subscribe API (event-engine, PubSub v2): channels, channel groups, presence channels, wildcard subscriptions, stream-filter expressions, and timetoken cursor restore, with typed listeners for messages, signals, message actions, files, presence, and App Context objects., Presence API: here-now, where-now, get/set presence state, and heartbeat., Channel Groups API: add and remove channels, list channels in a group, and remove a group., Message Persistence (Storage) API: fetch messages with metadata, message actions, file, message-type and publisher-UUID includes, reverse ordering, count and start/end bounds, delete messages, and message counts., Message Actions API: add, get, and remove reactions on published messages., Signal API: lightweight signal publishing., Files API: send, list, download, delete, generate a file URL, and publish a file message., App Context (Objects v2) API: get/set/remove UUID and channel metadata, list all UUID and channel metadata, and manage memberships and channel members., Access Manager v3 API: grant, parse, set, and revoke resource tokens., Mobile Push API: add, remove, and list channels for a device and remove a device, for the APNS2 and FCM gateways., Time API: fetch the current PubNub network timetoken. | | --- | --- | Last updated at: 2026-09-24T12:25:41.000Z