All notable changes to bloccs are documented here. The format is based on
Keep a Changelog, and this project
adheres to Semantic Versioning.
Unreleased
[0.6.0] — 2026-06-08
Added
Request/response —
Bloccs.call/4andBloccs.cast/4. A network was until now fire-and-forget:Bloccs.Producer.push/3returns once a message is admitted, never once it is processed, so a caller got nothing back. The new functions add request/response on top without making the pipeline synchronous — only the calling process waits.- A terminal node opts in with
reply = truein its[node]block and emits the response on an out-port. Bloccs.call(network_id, in_port, payload, opts)pushes to an exposed input port and blocks until that node replies, returning{:ok, reply}or{:error, reason}.:timeoutdefaults to5_000ms.Bloccs.cast(network_id, in_port, payload, opts)returns{:ok, trace_id}immediately; withsend_result: truethe caller is later sent{:bloccs_reply, trace_id, result}.
- A terminal node opts in with
Errors come back as data —
Bloccs.EffectError. When a node on a request's trace fails terminally — a bad inbound schema (:validate), the node raising / returning{:error, _}/ atimeout_msoverrun (:execute), or a downstream delivery failure (:dispatch) — the caller receives{:error, %Bloccs.EffectError{node, phase, attempt, reason}}instead of waiting out the timeout. Socall/4can tell "failed" from "slow";{:error, :timeout}is reserved for a request that is legitimately filtered/dropped (no reply and no error).cast/4withsend_result: truedelivers the typed error the same way. A retried failure is not reported (a later attempt may still reply). The other{:error, _}reasons are:no_producer | :unknown_network | {:unknown_port, p}(the request could not be admitted).Correlation reuses the per-message
trace_id(Bloccs.Lineage): the newBloccs.Collectorprocess keys an in-flight request on{network_id, trace_id}, registered synchronously before the push (so a reply/error for an unregistered trace is dropped, not buffered — plainpush/3and fire-and-forgetreply = truenodes cost the collector nothing) and enforces the timeout collector-side (a late reply can never crash a timed-out caller).Limitations: first-wins aggregation (one result per request); correlation (reply and error) does not survive a
[batch]/[join](which mint a freshtrace_id). SeeBloccs.Collector, the request/response guide, andresearch/12-request-response-primitive.md.
0.5.0 — 2026-06-07
Added
Per-message lineage tracking. Every message now carries a small lineage in its
Broadway.Messagemetadata (never the payload) so a single logical message can be tracked across the hops it takes through a network:%{msg_id: id, parents: [id], trace_id: id}msg_id— a unique id minted at each emit.parents— the input message id(s) that caused this emit: one for a transform/split, many for a batch/join fan-in (a causal DAG).trace_id— root correlation; propagated unchanged on 1:1 and fan-out, and minted fresh on fan-in (a merge is a new logical message;parentspreserves the cross-trace links).
A root lineage is minted at external ingress;
Bloccs.Router.dispatch/5threads it to each downstream producer and the runtime stamps it at every emit site (transform, split, filter, batch, join, join deadletter, retry). Subgraph composition needs no special handling —useis flattened into one namespaced network at parse time, so lineage threads across the seam for free.The
[:bloccs, :emit]telemetry metadata gains:msg_id,:parents,:trace_id(additive — existing consumers are unaffected). See the newBloccs.Lineagemodule.
0.4.0 — 2026-06-07
Added
Bloccs.Introspectnow exposes each node's contract and primitive config.node_view/1gained two fields so observability tools can show what code runs at a node and how a primitive is tuned without re-parsing manifests::contract— the author'spure_core/effect_shellrefs (as"Mod.fun/arity"), plustimeout_ms,retry, andidempotencypolicy.:config— the primitive block a node declares, as the relevantBloccs.Manifest.{Batch,Join,Rate}struct (ordelay_ms),nilwhen absent.
Both are additive; existing
node_viewconsumers are unaffected.
[0.3.0] — 2026-06-05
Added
Bloccs.Inspect— opt-in payload capture. Off by default. When enabled, the runtime attaches a rendered, bounded, redacted snapshot of each emitted payload to the[:bloccs, :emit]telemetry event under the new:payloadmetadata key (a string;nilwhen disabled), so observability tools (e.g. thebloccs_webMessages feed) can show message contents without holding the live term.config :bloccs, :inspect, enabled: true, max_bytes: 512, redact: [:password, :token, :secret, :authorization]Redaction matches map keys by name (atom or string) at any depth; structs keep their type.
Changed
- Relicensed from MIT to Apache License 2.0 (adds an explicit patent grant). Applies to this and future releases; previously published versions (≤ 0.2.0) remain under their original MIT terms.
[0.2.0] — 2026-06-05
Added
- Introspection API — a read-only window into running networks, the
foundation an observability dashboard (
bloccs_web) reads. All additive.Bloccs.Introspect—list_networks/0(summaries),network/1(a normalizedBloccs.Introspect.Networkwith nodes, ports, effects, edges, per-node concurrency, supervision strategy, and exposed ports),producers/1, andproducer_state/1.Bloccs.Introspect.glyph/1— the canonical notation glyph for a node manifest (:source,:sink,:split,:batch,:join,:throttle,:delay,:node_effect,:node), so the notation stays a property of the library rather than being reinvented by each viewer.Bloccs.Discovery— boot-time registration of running networks in a newBloccs.NetworkRegistry, so tools enumerate live networks in O(1) without scanning the supervision tree. Entries are owned by each network's supervisor and clean up automatically when it stops or crashes. The generated supervisor now callsBloccs.Discovery.register/2frominit/1— recompile networks built with an older bloccs (mix bloccs.compile) to make them discoverable.Bloccs.Producer.stats/1— a safe, typed snapshot of a producer's queue (size,buffer,blocked,pending_demand,utilization) via a boundedGenStagecall, so observers never reach in with:sys.get_state.- The generated supervisor gained
__bloccs_introspect__/0(topology + node→impl- supervision + exposed ports) feeding the API above.
0.1.1 — 2026-06-05
Changed
- Docs: dropped the README Status and "Out of scope" sections (the roadmap now lives in GitHub Projects), corrected the License note to plain MIT (no Pro call-out), and refreshed the post-publish wording now that bloccs is on Hex.
0.1.0 — 2026-06-05
First public release.
Added
- Manifest formats — TOML node manifests (
.bloccs, one node per file) and network manifests, parsed into typed structs (Bloccs.Manifest.*) byBloccs.Parser. - Validator —
Bloccs.Validatorenforces declared ports, end-to-end edge schema matching, DAG-only topology (cycle detection), effect declaration, and well-formedpure_core/effect_shellfunction refs. use Bloccs.Node— compile-time parse + validate of a node's manifest,@after_compilearity check of the contract functions, and an AST-walk warning on use of undeclared effects.- Code generator —
Bloccs.Compileremits a Broadway supervision tree as real.exsource under_build/<env>/bloccs_generated/<network>/(debuggable, PR-reviewable), one pipeline module per node plus a supervisor. - Runtime contracts, wired into the generated
handle_message: retry (constant/linear/exponential back-off, matched on failure reason),timeout_ms(bounded task per attempt), idempotency (atomic in-flight reservation by key), bounded-buffer back-pressure (producer parks the caller, never drops), and:telemetryspans. - Effect capability model — pure core + effect shell split; four effect axes
(
http,db,time,random); declared axes bind to real adapters, undeclared axes bind to a denied-capability stub that raises. Mock adapters by default; realBloccs.Effects.HTTP.ReqandBloccs.Effects.DB.Ectobehind a config switch, with:req/Ecto as optional deps. - Flow primitives —
:drop(filter) and{:emit, [{port, payload}, …]}(split / multi-emit) effect-shell return shapes alongside the single{:emit, port, payload}; merge (several edges into one in-port);[batch]windows (size/timeout_ms) reduced bypure_core;[join]correlating two or more distinct typed in-ports by a key (on) — each in-port compiles to its own pipeline; partials pasttimeout_msdead-letter;[rate]throttle and[delay]time-shift via the Broadway producer. A filtered message emits[:bloccs, :node, :dropped]. - Subgraph composition — a
[nodes]entry mayusea network manifest; the parser flattens it into namespaced leaf nodes at parse time. - Trace + coverage —
Bloccs.Tracerecords a run from telemetry to a.bloccs-trace;mix bloccs.coveragereports real structural coverage (in-ports, out-ports, edges reached) live (--message) or from a loaded trace (--trace). - CLI —
mix bloccs.new,mix bloccs.validate,mix bloccs.compile,mix bloccs.run(with--message,--port,--trace),mix bloccs.coverage. - Examples — a graded ladder:
examples/tour(core concepts, mock effects),examples/events(the flagship webhook processor — branching, fan-out, retry, timeout, idempotency, coverage), andexamples/real_backend(real HTTP to a local stub + real SQLite). - Guides — core concepts, getting started, manifest reference, architecture, and effect adapters.
Known limitations
- Cyclic networks are out of scope (DAG-only); feedback loops need a deadlock-safe edge mode still on the roadmap.