Release Notes

The Streaming Platform products — C21 Live Control and C21 Live Encoder — are delivered as software: a Docker stack on a Linux host, installed and updated with a single command. Each entry below describes what one version of that software delivers.

v6.10.8

June 29, 2026

• Skip a single occurrence of a recurring Schedule — Skip one occurrence of a recurring Schedule without affecting the rest of the series. Skipping is now also available from a voice agent.
• Extended restart protection in Schedule takeover: a Live stream started manually no longer stops or restarts when an automatic stop is scheduled, even if its configuration differs from the planned one — it adopts the running broadcast and applies only the end time.
• Optimized takeover of scheduled Live streams, avoiding unnecessary restarts when the configuration already matches the running broadcast.
• The On Air and Live Streams tables now support column sorting.
• MCP agents now automatically recommend the start device based on the actual occupancy of the available resources.
• Improved usability and accessibility of the YouTube/RTMP Destination configuration form.
• Simplified the Scheduler's recurrence options: the Monthly option is removed.
• Fix: Channels that use logos no longer fail to start.
• Fix: Improved automatic audio PID recovery on streams with multiple audio tracks.
• Fix: Removed repetitive, unnecessary Encoder log messages related to audio timestamp calculation.
• Fix: Fixed an issue where asking the agent to change the end time of a Schedule would confirm the change but not save it.
• Fix: Fixed a case where the Schedule calendar could appear empty in certain agent integrations.
• Fix: Fixed an error that prevented deleting a Live stream due to residues from previously deleted Schedules.
• Fix: Improved handling of date parameters (e.g., "from" / "until") in MCP agent tools.

v6.10.6

June 22, 2026

• Destination group editing via MCP agent — An MCP agent can add or remove Destinations in a group directly: updatePublishingGroup, getPublishingGroupById, and getAllPublishingGroups are now available to the agent. Group changes on live or stopped streams no longer require a manual step in the UI.
• Fix: Vertical and 9:16 encodings no longer fail at start with "No active outputs." Output selection now relies on the encoding group instead of a stale broadcast-level aspect-ratio field.
• Fix: On Nvidia GPU hardware, the crop required for vertical output is now applied correctly through a hwdownload → crop → hwupload_cuda round-trip.
• Fix: Starting a Live stream whose destination group has no active Destinations is now blocked at the API with error APIF655 (422), consistent with the guard already in place at create and update.
• Fix: Calendar event blocks in the Scheduler Week and Day views now fill their container — a 4-hour event is visually 4 hours tall.
• Fix: Name-based search and column ordering now work in the Encoding Groups, Destination Groups, and Device Groups management tables.
• Fix: CVE-2026-12143 — form-data dependency updated to 4.0.6 (was 4.0.5). No runtime behavior change.

v6.10.4

June 15, 2026

• Edit Destination groups in use — Add or remove Destinations in a group while it backs running Live streams; the encoder engages an added Destination at runtime, with no stop and start.
• Destination group pool model — A group holds up to 20 Destinations; the encoder keeps up to its licensed publishing-point count active at once, sharing the slots dynamically.
• Protected system encoder groups — System-managed encoder groups are hidden from the list and rejected for edits, so they cannot be changed by accident.
• Input compatibility check on start — Starting a Live stream validates the input type against the chosen on-prem or cloud encoder group, and pins physical inputs to their wired device.
• Per-segment HLS program-date-time — HLS outputs under Source-Synchronized Encoding embed an EXT-X-PROGRAM-DATE-TIME tag per segment, keeping signals aligned across encoders.
• The On Air window now reflects Destination-group changes automatically, with no manual refresh.
• MCP agents list only valid C21 Live Cloud accounts as Live stream start devices.
• A Live stream's status over the API and MCP now reflects the real publishing state of its Destinations.
• Asset uploads to MediaCopilot now transfer in passthrough, avoiding unnecessary re-encoding in the service.
• Public OpenAPI contract descriptions are simplified to focus on the platform's observable behavior.
• Fix: Saving the selected Destinations when creating or editing a group from the UI now works.
• Fix: Live streams can now be created with an empty Destination group.
• Fix: Inconsistencies in handling Destination groups used by active broadcasts are resolved.
• Fix: Improved documentation of the GET /livestreams/{id}/status endpoint.

v6.10.3

June 8, 2026

• MCP server: expanded agent control — A chat or voice agent drives live operations via the MCP server: input-aware on-prem/cloud placement, scheduling, hot source switch and status.
• Schedules are created "closed" — bound to an encoder group with active Destinations — so a scheduled live no longer fails to start; the editor requires selecting the encoder group.
• Clearer error messages when scheduling across dates and time zones.
• Single-program Destinations (RTMP, SRT, SDI, Stream) now emit only the highest quality when a live has multiple renditions; adaptive Destinations (HLS, DASH, CMAF, Enhanced RTMP) keep all of them.
• Logging and stability refinements.
• Fix: Updating a Destination's stream key (including RTMP), even while the live is on air, now applies reliably on the encoder.
• Fix: Hot source switch to a YouTube Live input no longer fails to start.
• Fix: SSL certificate import is more robust — it accepts EC keys and applies the certificate correctly in the service.

v6.10.2

June 3, 2026

• License install from the CLI — Install a license file on the Encoder with liveencoder license install.
• Encoder credential management — Show and rotate the Encoder's registration credentials with liveencoder credentials show | reset.
• Configuration list tables (Sources, Devices, Encodings, Destinations) and External Storage now sort on a column-header click.
• Cleaner Encoder configuration template — obsolete and unused settings removed; the Encoder no longer manages host networking or NTP.
• Fix: Live streams using the logo video codec now produce standard-compliant HLS, fixing black playback and rejection by strict players and third-party systems such as AWS MediaPackage.
• Fix: Adding an Encoder device from the Control UI no longer fails with an HTTP 500 error.
• Fix: Validating a C21 Live Cloud account with no Encoder product now completes successfully.
• Fix: The livecontrol token CLI (create, list and revoke bearer tokens) works again.

v6.10.1

May 27, 2026

Foundation release

v6.10.1 closes the v5 → v6 transition. The two products — Live Control and Live Encoder — stop being an appliance and become a pair of composable services that you install and update with a single command on the hosts you manage. This release captures the shape of the platform from v6 onwards as a reference; subsequent v6.10.x and v6.11.x entries follow the standard Feature / Improvement / Fix format.

v5 → v6.10.1 at a glance

C21 Live Control — orchestration, UI, agents and integrations

Live Control is the control plane of the platform. It orchestrates Channels, Encodings, Destinations and runtime operations across one or more Encoders, and exposes the operator UI, the public REST API, the MCP server and the external integrations.

UI — Vue 3 control plane

The whole operator UI is Vue 3 on a single design-token system. Four sidebar groups cover the operation:

• Live production — On air, Live streams, Scheduler, Recordings, Asset Library.
• Configuration — Devices, Sources, Encodings, Destinations.
• Settings — Users, Security, Assets, External Storage, Integrations.
• System status — Commands and Logs.

See On air and Live streams.

REST API — /c21apiv2

The public API exposes every operator surface as named operationId endpoints — used directly for scripting and integrations, and internally by the MCP server.

• Bearer-token authentication with first-class API tokens (POST/GET/DELETE /c21apiv2/security/tokens); tokens inherit the issuing user's role.
• Stable error catalogue with APIf*, SECf*, SYSf*, DRMf*, MNTs* prefixes — codes hold across releases.
• Pagination envelope — every list endpoint returns the same {rows, pagination} shape (1-based page, default pageSize=500).
• Idempotent mutations through the Idempotency-Key header — safe retries do not duplicate side effects.

See REST API.

MCP server — AI and agent integration

Live Control ships its own MCP (Model Context Protocol) server, wrapping a curated subset of the REST API as a tool catalogue any MCP-compatible client can call.

• Server-side profiles (voice, readonly, operator, full) bound the tool catalogue advertised to each connected client.
• Shared authentication with the REST API — one API token unlocks both surfaces; the operator's role still applies.
• Audit parity — every MCP call carries the same X-Request-Id trail as the equivalent REST call.

See MCP server.

Security

The v6.10.1 baseline assumes a hostile network and adversarial-operator scenarios.

• Password policy. SHA-512 hashing, configurable history (3–10), lockout (3–10 failed sign-ins), expiration (1–999 days), inactivity timeout (15–60 min). Force-rotate via livecontrol security password reset <user>.
• Roles. Two product roles — System Administrator (full surface, including licenses and integrations) and Operator (day-to-day broadcast). API tokens inherit the issuing user's role.
• CVE remediation. Every Docker image gates on Trivy in CI. The v6.10.1 image set ships with no known High or Critical CVEs.
• License enforcement for C21LiveControl, C21LiveEditor, C21LiveDeploy, C21LiveYouTube, C21LiveEncoder, Multi Publishing Points and UDP Recovery.

See Security and Licenses.

Integrations

External integrations are first-class CRUD surfaces, gated on the System Administrator role.

• C21 Live Cloud. Account-based access to the Cires21 managed cloud platform; registering an account unlocks the Stream – C21 Live Cloud Channel type (RTMP, SRT or UDP-R transport) and its matching cloud Destinations. See C21 Live Cloud.
• DRM providers. Multi-DRM via SPEKE (Widevine, PlayReady, FairPlay) on CMAF, DASH and HLS outputs. The provider catalogue currently covers AXINOM and EZDRM. See DRM.
• MediaCopilot. Two paths into the Cires21 MediaCopilot SaaS for transcription, subtitling, dubbing and automatic clip generation:
  • Live ingest — MediaCopilot appears as an HLS Destination provider; Live Control pushes the live segments to the configured MediaCopilot tenant during the broadcast, so the MediaCopilot pipeline processes the asset while the broadcast is still on air.
  • Send-to from the Editor — a closed Recording or a clip cut from it in the Editor is exported via exportMediaCopilot for asynchronous processing.
  
  Both paths share the same MediaCopilot account configured at Integrations → MediaCopilot. Gated on the C21LiveEditor license. See MediaCopilot.

C21 Live Encoder — media processing engine

Live Encoder is the streaming engine of the platform. It captures sources, encodes streams and delivers outputs. Live Control attaches one or more Encoder instances as Devices and drives them remotely; the Encoder itself has no operator-facing UI.

Media pipeline

• Inputs. SDI, AES/EBU, NDI, SRT, Stream – C21 Live Cloud, MPEG-TS Stream, File, Youtube Live.
• Encoding. H.264, HEVC, VP9 with NVIDIA NVENC and Netint Quadra acceleration. HDR full support (hdr_mode = sdr / bt2020_sdr / hlg / hdr10). CBR improvements.
• Multi-audio. Multiple audio programs processed per broadcast — track mapping and language tagging carried through to the outputs.
• Outputs. HLS / TS, DASH, CMAF, RTMP, Enhanced RTMP, SRT, MPEG-TS over UDP/RTP, SDI passthrough (now part of Multi Publishing Points), Recording.
• Real-Time encoding — sub-second contribution pipeline for low-latency scenarios.
• SCTE-35 signaling — ad-insertion markers propagated end-to-end on HLS / TS outputs.
• CMAF Ingest (Interface-1) with TTL control and Unified Streaming compatibility.
• DVB Teletext and OP-47. Subtitle support from these two input types.
• DRM at encode — per-destination encryption via SPEKE keys on CMAF, DASH and HLS outputs.
• Source Synchronized Encoding (SSE) — two or more encodes locked to the same source frame timeline, producing CMAF outputs that pair losslessly downstream.
• Mid-broadcast source switching — swap the source Channel of a running broadcast without stopping it.
• Youtube Live acquisition — native Youtube Live Channel type; the Encoder fetches the upstream session and treats it as a contribution input.

See Sources, Encodings and Destinations.

Deployment — common to both products

Live Control and Live Encoder ship the same operational shape on the host: a Docker stack brought up by a one-line installer, backed up before every update, with a parallel CLI surface for day-to-day operations.

• One-line installers. curl -fsSL https://get.cires21.com/livecontrol | sudo bash brings up the Control stack; the equivalent URL brings up the Encoder. Both expose --version, --check-only and additional flags documented in Installation.
• Backups + rollback. livecontrol backup / livecontrol restore <file> for snapshots of the database and configuration on Control; the Encoder ships a parallel liveencoder backup / restore. The installer takes a backup before every update and rolls back automatically if any step fails.
• OS posture. Control runs on Ubuntu 22.04 LTS or 24.04 LTS; Encoder runs on Ubuntu 24.04 LTS, kernel ≥ 6.8. Both are validated against Ubuntu Pro for regulated Tier-1 deployments.
• CLI surface. livecontrol status / start / stop / restart / logs / config / backup / restore / update / ssl / security / cleanup / uninstall. The Encoder ships a parallel liveencoder CLI with gpu and streams subcommands for runtime diagnostics.

See Installation, Encoder install and Updates.

What's next

From v6.10.2 onwards, release notes return to the standard Feature / Improvement / Fix format.

For the source-level changelog, the product git tags carry the merged pull-request history.