0.55.0 - 2026-08-03

Release Notes

Added

• File-configured hosts can now bound delegated fan-out with [limits] max_live_agents
  (C-471). The ceiling counts the root and every transitive child in one shared census, so 0 and
  1 both disable delegation and a spawn over the limit is refused immediately. Combined with
  max_concurrent_tool_calls, it bounds simultaneous tool execution across the tree at the product
  of the two values. Project config overrides user config; an explicit host limit wins over the
  autonomous posture preset.

Changed

• The CLI now reads its compaction fallback from the agent-owned default instead of carrying
  three copies of 48,000 (C-466). FLUX_COMPACT_CHARS precedence, 0 disabling, and malformed
  value warnings are unchanged; changing the shared default now moves CLI, served, SDK, and checked
  documentation surfaces together.

• The 48,000-character compaction default is now an explicit fixed history budget, not an
  unresolved model-window approximation (C-462). Recorded usage shows whole-request prompt size is
  dominated by more than conversation history, and Flux has no trustworthy context-window metadata
  for arbitrary local, custom, or evolving model ids. The runtime value and override precedence are
  unchanged; code and docs now state that operators should tune the existing per-agent / environment
  override when their known workload needs a different retained-history cap.

• Flux-Lang context slicing now has one honest, deterministic token-budget policy instead of two
  unused extension points (C-469). It always uses its documented four-characters-per-token
  estimate; the host counter argument and both unrelated TokenCounter traits have been removed.
  Removing the public traits and the slice_context argument is a breaking change for direct
  flux-provider / flux-lang callers and therefore a next-minor release change. Production Flux
  behavior is unchanged because no provider implemented the capability and the only runtime caller
  never supplied a counter.

Fixed

• Malformed adaptive-stage results now identify their producer instead of blaming Flux-Lang
  (C-327). The detect_intent and explore reflect boundaries require a tagged JSON object before
  the authored loop reads .kind. Scalar or untagged results halt with the stage name, returned
  type, and a bounded executor-redacted excerpt retained in the step trace.

• The plugin hash-drift test no longer copies a whole binary into ambient /tmp (C-468).
  Its writable fixture now lives in a unique, automatically cleaned directory beside Cargo's active
  target binary. A staging failure names that directory and its storage cause before any hash check,
  so tmpfs pressure can no longer masquerade as a verification regression.

• Malformed FLUX_COMPACT_CHARS overrides now warn on served agents as well as the CLI
  (C-507). Both surfaces consume one flux-agent parse/outcome contract: missing, valid, and 0
  values stay quiet, while an explicit invalid value names the rejected input and shared fallback.
  A per-agent compact_threshold_chars setting still wins without consulting the environment.

• /compact now reports whether it actually rewrote the conversation (C-465). The REPL no
  longer prints context compacted for an under-threshold, disabled, unsplittable, empty-summary,
  or cancelled check; successful rewrites carry their before/after message counts. The published
  FlowEngine::maybe_compact API now returns CompactionOutcome instead of (), a breaking change
  for direct flux-flow callers and therefore a next-minor release change.

flux-cli 0.55.0

Install flux-cli 0.55.0

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/codewandler/flux/releases/download/v0.55.0/flux-cli-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/codewandler/flux/releases/download/v0.55.0/flux-cli-installer.ps1 | iex"

Download flux-cli 0.55.0

File	Platform	Checksum
flux-cli-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
flux-cli-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
flux-cli-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
flux-cli-aarch64-unknown-linux-gnu.tar.xz	ARM64 Linux	checksum
flux-cli-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

codewandler-flux-lsp 0.55.0

Install codewandler-flux-lsp 0.55.0

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/codewandler/flux/releases/download/v0.55.0/codewandler-flux-lsp-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/codewandler/flux/releases/download/v0.55.0/codewandler-flux-lsp-installer.ps1 | iex"

Download codewandler-flux-lsp 0.55.0

File	Platform	Checksum
codewandler-flux-lsp-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
codewandler-flux-lsp-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
codewandler-flux-lsp-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
codewandler-flux-lsp-aarch64-unknown-linux-gnu.tar.xz	ARM64 Linux	checksum
codewandler-flux-lsp-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum