v0.3.0

Implements Synod 0.3. synod version prints language 0.3, synod new writes synod 0.3, and trace headers say "synod":"0.3". A synod.mod that says an older version (synod 0.2) is still accepted, and the version line does not gate features; a newer one (synod 0.4) is an error.

Changed

• The embedded look/basic follows std: message tags show only mid-flight. Scene ids and goldens change; traces are unchanged.
• look.Flight moves the flown shape from the edge of a to the edge of b, 8 clear of each box (the Place size model, group extents, proportional clamp when the cards are close, halfway between the clipped ends when dropped; straight up above the shape when both are at one position). Scenes with flights change; traces are unchanged. The embedded std follows std.
• The ring layout is wider and sits higher: radii 380 and 170 (growth up to 1.4 in height), and the ring, row and grid layouts centre on (520, 315), 10 above the scene centre, since state rows hang below the cards. An even number of cards turns half a slot counter-clockwise, so n1 is at the left or top left. Scenes change; traces are unchanged.
• sim.StateRows gives each row at most 24 characters (StateRowMax): a longer one keeps its first 23 and ends in …. Look-only, so traces keep full values. The embedded std and the vendored examples follow std and examples.
• The fit test also checks a mid-scene key, that every state row has at most 24 characters, that rows clear other cards and icons by 8, and that no two labels overlap.
• The embedded look/basic writes the lesson note at the top of the canvas (y 40). The fit test measures notes and reasons against cards, rows, heads, icons, counters and each other, with no exclusion, and counts a counter as a box.
• The embedded and vendored paxos keeps its promise, accepted proposal and round on std/disk; only the paxos trace gains disk.Written events, every other trace is byte-identical.
• Scenes use a 1040 by 650 canvas with its centre at (520, 325), look.Orbit has radius 200, and the ring layout is an ellipse (radii 300 and 150, turned half a slot for an even number of cards, growing up to 1.4 with the number of cards). Default-theme scenes change once; traces are unchanged. The embedded std and the vendored examples follow std and examples.
• look.Place s beside t puts s on the right of t when its box lies inside the canvas there (t at the position it settles at) and on the left of t otherwise, with the same gap and sizes; the side is chosen when the Place runs. Scenes with a note beside a card at the right edge change; traces are unchanged. The fit test also checks every label at each of its own key times.

Fixed

• synod new demo is refused like main, time and sim, with or without --lib: the package demo collided with demo/demo.synod, the main program, which overwrote the library.
• synod check (and fmt, doc) over a folder that holds two module folders with the same module path, such as counter/synod.mod and proj/counter/synod.mod, panicked while lowering because both modules' packages shared one import path. It now reports error[duplicate-name]: module "counter" is declared by two folders, counter and proj/counter at the second synod.mod, with the hint to check one module folder at a time, and exits 1.

v0.2.7

Implements Synod 0.2. The documentation is now checked against the compiler, and synod get downloads are byte-exact.

Added

• internal/forms and internal/forms/cmd/doccheck (not linked into synod or synod.wasm): the catalog of the forms of spec/02, the types of spec/04, the contexts of spec/05 and the std packages, checked against the spec text, and doccheck, which checks the tutorial and the Library examples of dsl (decisions 104 and 105): coverage, order of introduction, synod new and examples/raft copies, golden summaries, "why" programs and one runnable example per std phrase. A docs job in CI runs it once the pinned dsl has a tutorial.

Changed

• synod explain --json: example.files holds every file the example is checked or run with, the implied synod.mod included (decision 111). The text form, --catalog and the MCP tool are unchanged.

Fixed

• synod get checks out modules byte for byte (no line-ending, filter or attribute conversion), refuses symbolic links by tree mode and tolerates two synod get processes racing on the store.

v0.2.6

Implements Synod 0.2. Tools for people and agents: synod doc and synod explain answer questions from the command line, synod new and synod get start a module and fetch what it requires, and synod mcp serves the lot to agents that have no shell.

Added

• synod doc [package]: prints a package's phrases, records and Node fields from its source, or lists the visible packages. --json prints synod-doc/1, --scope file gives the scope of one file for editors, --overlay file reads unsaved buffers and --catalog prints the std catalog as Markdown.
• synod explain [code]: explains a diagnostic code with an example and its fix, or lists the 38 codes. --json prints synod-explain/1; --catalog prints the table of codes, meanings and fixes as Markdown.
• synod new <dir> [--module path] [--lib]: creates a module with synod.mod, .gitignore, a package folder and a demo.synod main file that checks and runs.
• synod get [module@version]: makes vendor/ and synod.sum match the build list, downloading what the store lacks with git and verifying the commit and the tree hash.
• synod mcp [--root dir]: a stdio MCP server with the tools doc, explain, check, run_summary and fmt; each gives the text of the matching command.

Changed

• The embedded std matches std v0.2.2: every phrase, record and field has a doc comment, and these comments are what synod doc prints.
• synod version lists the new formats: formats synod-trace/1 synod-scene/1 synod-check/1 synod-doc/1 synod-explain/1. The same list is in synod.version() of the WebAssembly build.

v0.2.5

Implements Synod 0.2. Editors and learning modes: synod check can read unsaved
buffers and still colors a file that does not parse, lesson.Ask can offer
choices, and a run-time error inside std now points at the user's own code.

Added

• synod check --overlay <file> (synod-overlay/1): checks each listed .synod file or synod.mod as if it held the content of another file; diagnostics and tokens keep the original path and positions. A missing overlay, a bad format or a key that is not an existing file is exit 2.
• synod check --json --tokens lists lexical tokens (language, value, comment and name, without def) for a file that fails to lex or parse, for every other file of its package and for extra main files, so an editor keeps its highlighting while the user types.
• lesson.Ask [q: text] choosing [c: list of text] for Predict: 2 to 6 distinct, non-empty choices, else a bad-argument run-time error.
• scene.json shapes carry node and msg (the node or message a shape stands for), and pause markers carry choices when the question has choices.

Changed

• A run-time error raised while std code runs is reported at the position in user code of the call that entered std, in the trace (sim.Failed), the failed at and look failed at lines, the scene's failed marker and the rich form; the std position is kept as a note (decision 89). lesson.Ask … choosing with bad choices now points at the lesson.Ask call, not at std/lesson/lesson.synod.
• The trace record lesson.Asked gains the field Choices ({} for a plain lesson.Ask), so every trace and summary of a program with a question changes.

v0.2.4

Implements Synod 0.2. The compiler now also runs in the browser: synod.wasm
checks, formats, runs and draws programs with exactly the same output as the
command line, ready for the website's interactive examples.

Added

• synod.wasm, the compiler for WebAssembly (GOOS=js GOARCH=wasm, built from cmd/synod-wasm): a global synod with the synchronous functions check, run, format and version. They take the program as a files object and return the CLI's check.json, status, summary, trace and scene as text, byte-identical to the native build; they never throw (errors are {code, message} with exit code 2). std is embedded; other modules come in files under vendor/.
• Release assets synod-<tag>.wasm (about 8.4 MiB, 2.2 MiB gzipped) and synod-<tag>-wasm_exec.js (from the Go toolchain that built the module), both listed in SHA256SUMS. go run ./internal/release/cmd/wasm -tag <tag> -out dist builds them and fails over the size budget (9.5 MiB, 2.75 MiB gzipped).
• CI runs the runtest and driver goldens compiled to WebAssembly under Node, diffs the trace and scene hashes against Linux, and compares the JS API running in Node with the native API and the goldens (internal/wasmtest).

Changed

• The call-depth limit is 500 nested calls on every target (it was 10000), in the simulator and in the scene builder (value.MaxCallDepth): the WebAssembly build overflows the JS stack of plain Node at about 3000 nested calls, and browsers can have smaller stacks. The run-limit message is still more than <limit> nested calls.
• synod check and synod fmt skip folders named vendor when they walk a folder, like testdata, .x and _x; an explicit file or folder argument is still processed.

v0.2.3

Implements Synod 0.2, now complete. synod run draws the run: next to the
trace it writes scene.json, the animation the player will show. Programs
without their own look are drawn by the default look: node cards with their
state, messages flying between nodes, crashes, broken invariants and
captions.

Added

• synod run writes out/scene.json (synod-scene/1) next to the trace and prints scene <length>, <n> shapes -> out/scene.json (the length in seconds, such as 147.98s) after the existing status lines. The scene is written for every run, also after sim.Failed; --summary prints the same text as before and writes the scene silently.
• --scene file (- for stdout, with the status lines on stderr; --trace - and --scene - together exit 2), --pace x (0.25 to 4, up to three decimals) and --mode ordered|proportional. --watch and --json-events still exit 2.
• The scene builder runs the observers of the program's looks over the facts of the run. A program that does not use std/look is drawn by std/look/basic: node cards, state rows, message flights, the sim.Broken border and lesson captions.
• A fault inside a look is a look failure, not part of the trace: look failed at <time>: <pos>: error[<code>]: <message>, exit 1, and a partial scene with a failed marker.
• trace.Decode reads trace.jsonl back into facts; Build(facts) equals Build(Decode(Encode(facts))).
• std: look.Flight, net.Id, net.Type, sim.StateRows, and look.Tween of "x" and "y" to a shape; look.Travel, look.Remove and std/look/basic are ordinary Synod.
• Golden scene.json for every example, scene determinism over 20 seeds, scene hashes in the cross-OS CI job, FuzzScene in the weekly fuzz run, and BenchmarkScenePing5000.
• The run fuzz target and the generator now also build scenes, with generated looks.

Changed

• The status of a failed run is followed by the scene line, so the rich failed at … goldens of testdata/run/errors end with it.

v0.2.2

Implements Synod 0.2. Errors now look like a good compiler's: on a terminal,
every compile-time and run-time error shows the source line, underlines the
exact problem, points at related places ("first defined here", "called from
node context here", "this is 0") and shows the fix as a diff. Piped output,
which agents and CI read, is unchanged byte for byte.

Added

• --style rich|short and --color auto|always|never on synod fmt, check and run (both --flag value and --flag=value; a bad value exits 2). Rich output draws the source line with markers, labels, notes and help under the unchanged first line; it is the default when the destination is a terminal. Piped or redirected output stays the one-line form byte for byte. Color needs NO_COLOR unset or empty and TERM other than dumb; the flags beat the environment. --json ignores both flags.
• synod run failures render a snippet under the failed at … line in rich style.
• check.json diagnostics gain end, and label, labels, help (with edits) and notes when present; the format stays synod-check/1.
• A diagnostic without a position prints as path: error[code]: message.
• Fixes shown under help: for missing parentheses, imports to add, remove
  or rename, the package header, canonical form, receivers, sim.Nobody,
  "did you mean" names and more; each is tested to remove its error.
• Hidden control and bidi characters in source are neutralised in snippets,
  so a file cannot inject terminal escapes.
• Golden cases of testdata/check have expect-rich.txt and expect.json next to expect.txt; testdata/run/errors cases have expect-rich.txt.

v0.2.1

Implements Synod 0.2. synod run simulates a program deterministically and writes its trace.

Added

• synod run <folder> checks the folder's main file and runs it in the
  deterministic simulator: simulated time, nodes with crash and restart,
  a network with latency, loss, partitions and targeted drops, per-node
  disk, and the always invariants checked after every step. It writes
  out/trace.jsonl (synod-trace/1) and prints one status line. The same
  program and seed give a byte-identical trace on every platform.
• --seed n (or --seed=n, a whole number from 0 to 2^53) replaces the
  seed of the run; it wins over sim.Seed. Without either the seed is 1.
• --trace file chooses the trace file (parents are created); --trace -
  writes the trace to stdout and the status line to stderr.
• --summary prints a compact text summary of the run (steps that
  recorded facts, invariant results, final state of every node) instead of
  the status line, for agents.
• Every native phrase of the std catalog works: sim, net, time,
  random, lists, maps, math, text, disk. The look phrases and
  the observers wait for a later release; --scene, --pace, --mode,
  --watch and --json-events are recognized and exit 2 with
  not implemented yet.
• Run-time errors, reported as the last sim.Failed line of the trace,
  failed at <time>: <pos>: error[<code>]: <message> and exit 1:
  missing-key, index-range, division-by-zero, nobody, disk-type,
  time-limit (10 minutes of simulated time), bad-argument,
  number-range and run-limit (steps at one instant, call depth,
  collection size).
• Exit codes of synod run: 0 for a run that ended (also when an always
  broke, which is a result, not an error), 1 for diagnostics or a failed
  run, 2 for usage and I/O errors.

Changed

• sim.Seed and math.Hash are specified completely in the std catalog
  (domain and precedence of the seed; the exact FNV-1a based hash).
• Demo seeds that did not tell their story under the final simulator
  semantics were changed (gossip 15, paxos 105, twopc 1, cassandra 4) and
  the ring demo places other keys; see "Notes for implementers" in the
  examples.

v0.2.0

synod check now understands whole programs: it loads modules, finds the
phrase every sentence calls, and checks types and contexts, reporting every
compile-time error of specification v0.2.1. Running programs
(synod run) comes in the next release.

Added

• Language types and their acceptance rules (list of T, map of K to V,
  node types Node and p.Node).
• The standard library, embedded in the binary: every phrase of the std
  catalog, with native declarations and the phrases written in Synod.
• Module loader: synod.mod, package graph, main files next to their
  library, std/ imports, remote modules from the
  module's vendor/ folder, import cycles.
• Fixes that need the package loaded, for synod fmt: record settings
  order, name case, and a dropped own-package qualifier.
• synod check now checks whole programs, not just their form. It finds
  the phrase every sentence calls, checks the types of values (arguments,
  operands, list and map items, node types such as raft.Node, and
  results), infers the type of {} from how it is used, and reports
  every error code of the specification: type-mismatch, ambiguous-empty,
  missing-result, value-as-statement, action-as-value, context
  (what may run in node, main, check and look code) and foreign-state
  (node code that touches another node's state). Every example and every
  std package checks clean.

Changed

• synod fmt applies the fixes above when the package loads; a file in a
  package that does not load is formatted as before.
• Diagnostic paths are shown relative to the working directory when inside it.
• CI and release workflows use the Node 24 versions of GitHub Actions.

v0.1.0

The first release: the front end of the Synod compiler. It reads, checks
the form of, and formats Synod source for specification v0.2.0. Running
programs (synod run) comes in a later release.

Added

• synod fmt [paths…] rewrites .synod files into canonical form;
  --check lists the files that would change and exits 1.
• synod check [paths…] reports syntax, indentation, header and
  canonical-form errors, with a hint showing the canonical line;
  --json prints the synod-check/1 format.
• synod version prints the language, compiler and format versions; the
  compiler line shows the release tag and the commit it was built from.
• Lexer and parser for the whole structure grammar: indentation blocks,
  comments, continuation lines (else, otherwise), holes, typed
  collections, members, import paths.
• Canonical formatting: numbers, durations and colors respelled; single-item
  parentheses removed; not (…) rewritten to the direct operator; imports
  hoisted and sorted; blank lines and comments laid out.
• Binaries for macOS (arm64, amd64, universal), Linux (amd64, arm64) and
  Windows (amd64, arm64); install with Homebrew
  (brew install synodlang/tap/synod), Scoop, install.sh or
  go install. See https://synodlang.github.io/install/.

Known limitations

• Binaries are not code-signed: macOS and Windows warn when they are
  downloaded with a browser. Package managers and install.sh avoid this.
• Phrase resolution, types and contexts are not checked yet.