New features

• Wire-level message log for debugging: M-x port-toggle-message-log (or port-log-messages t) mirrors every outgoing form and incoming parsed message to *port-messages*, timestamped to the millisecond and labelled user / tool. Off by default.
• Eldoc highlights the active argument and shows a short docstring preview alongside the arglist. Multi-arity arglists are parsed and the arity matching the current position picked automatically. Customisable via port-eldoc-arg-index-function and port-eldoc-arglist-formatter.

Bugs fixed

• Fix Emacs hang when a large prepl response (e.g. the completion warm-up against a namespace with thousands of vars) arrived in many TCP chunks. The process filter used to re-parse the accumulated buffer from byte 0 on every chunk; it now defers parsing until a real newline arrives, at most one parse per inbound message. ~10x speedup on 100KB responses.

Changes

• REPL input-completeness check rewritten on top of parse-partial-sexp + the new port-repl-input-syntax-table defvar. Same observable behaviour, override-friendly for dialect variants.

• Optional inline result overlays. Set port-eval-overlay' to t' and each interactive eval (C-c C-e' on a sexp, C-c C-c'
  on a defun, etc.) places a => VALUE' overlay at the end of the form, dismissed by the next command. Composes with port-eval-display': you can keep your minibuffer / REPL
  output and add the overlay on top. Errors get the
  port-eval-overlay-error-face'; long values are truncated to the first line (full text still lands in the REPL when port-eval-display' is `both'). Off by default, so the
  existing minibuffer-or-REPL UX is unchanged.

• xref-find-definitions now offers tab-completion at its prompt,
  drawing from the same per-namespace cache `completion-at-point'
  uses. Falls back to free-form input when the cache is cold so
  the prompt always works.

• M-x port jacks in to babashka projects (bb.edn). The
  spawned command is bb -e <server-form>, identical to the
  tools-deps / Leiningen invocations modulo the program name and
  the dropped -Sdeps step (bb resolves classpath via bb.edn).
  Pretty-print :valf works in bb too, so taps and eval results
  arrive multi-line. port-jack-in-babashka-program overrides
  the bb binary; port-jack-in-extra-deps is ignored for bb.

• completion-at-point no longer blocks Emacs on every keystroke.
  Port now fetches the full symbol list for the buffer's namespace
  once and filters Elisp-side on subsequent capf calls; corfu /
  company-mode auto-popup feels instant after the first hit. The
  cache is warmed asynchronously when port-mode' is enabled with a session live, expires after port-completion-cache-ttlseconds (default 10), and gets cleared eagerly whenport-load-file' or
  port-set-ns' runs. M-x port-completion-clear-cache' forces a
  refresh. Set port-completion-use-cache to nil for the previous
  one-query-per-keystroke behaviour.

• Trace-frame jumps in *port-stacktrace* now reach jar-only
  frames. RET on a frame whose :file doesn't resolve under
  default-directory or a project source root now asks the JVM
  via clojure.java.io/resource over the tool socket; jar URLs
  open the slurped source in the same *port-jar: ...* buffer
  cache M-. uses, file: URLs visit the path directly. Two
  new defcustoms: port-stacktrace-frame-form (the lookup
  template) and port-stacktrace-frame-timeout.

• Breaking: port-find-definition is gone; replaced by a real
  xref-backend-functions entry installed by port-mode. The
  default M-. / M-, bindings now route through Port whenever
  a session is live, and xref-find-apropos (C-M-. by default)
  returns matching symbols across all loaded namespaces, each
  resolved to its file:line. Two new defcustoms:
  port-xref-apropos-form (the apropos query template, mirroring
  port-xref-form) and port-xref-apropos-timeout (default 5
  seconds, since walking all-ns isn't free). References aren't
  implemented; for that, layer clojure-lsp via eglot or lsp-mode.

• clojure.test runner with a structured report buffer. Four
  commands under C-c C-t: t runs the deftest at point, n the
  current namespace, p every loaded test-bearing namespace, and
  r re-runs whatever failed or errored last. Results land in
  *port-test-report* with per-failure sections showing
  expected/actual and a file:line link to the source; RET on a
  link jumps, n/p walk failures, g re-runs the same
  selection. Errors carry the captured Throwable->map, so RET
  on (RET to show stacktrace) pops the existing structured
  stacktrace buffer. The Clojure-side machinery is held in
  port-test-bootstrap-form; the four entry-point templates are
  individual defcustoms (port-test-run-ns-form etc.) for dialect
  or library overrides.

• Optional Orchard and
  Compliment
  integration via port-orchard.el. M-x port-enable-orchard' probes the running prepl for orchard.info' and compliment.core' and swaps in richer form templates for doc, eldoc, apropos, find-definition, and completion — independently per library. Or setq' the
  port-orchard-*' / port-compliment-*' defconsts persistently in
  your init.

• port-enable-orchard-on-connect defcustom: when non-nil,
  port-enable-orchard' runs automatically after every successful jack-in / port-connect'. Paired with `port-jack-in-extra-deps' it
  gets Orchard from "opt-in" to "always on" in two settings lines.

• port-after-connect-hook: a hook run at the end of port-connect' once the tool-socket bootstrap has been installed. Used internally by port-orchard.el' for the auto-enable wiring; available for any
  user-side extension that needs to fire helper-command requests
  immediately after connect.

• Dedicated *port-taps* history buffer for values published via
  tap>. Each tap is appended with a timestamp header and rendered
  in clojure-mode (or clojure-ts-mode) for syntax highlighting.
  port-show-taps / port-clear-taps are bound to C-c C-t v /
  C-c C-t c in port-mode; the buffer is capped at
  port-tap-max-entries (default 100).

• port-jack-in-extra-deps defcustom: alist of (DEP . VERSION)
  pairs that get spliced into the JVM start command at jack-in
  (clojure -Sdeps {...} for tools-deps, chained
  lein update-in :dependencies conj for Leiningen). Combined with
  the new `port-jack-in-orchard-deps' preset, opting into Orchard +
  Compliment is now a one-liner:

  (setq port-jack-in-extra-deps port-jack-in-orchard-deps)
  

• port-jack-in is now an alias for port' — discoverable under the CIDER-style name for users with cider-jack-in' muscle memory.

• Jack-in now configures io-prepl with a clojure.pprint-based
  :valf by default, so :ret and :tap values on the user socket
  arrive pretty-printed (bounded by port-print-length /
  port-print-level). Set port-jack-in-pretty-print to nil for
  the old single-line pr-str behaviour.

• Every Clojure form Port sends to the prepl is now held in a
  defcustom — port-doc-form, port-source-form,
  port-apropos-form, port-macroexpand-1-form,
  port-macroexpand-all-form, port-load-file-form,
  port-set-ns-form, port-eldoc-form, port-completion-form,
  and port-xref-form. Each defaults to a JVM clojure.repl/*-style
  form; override to target a different dialect (ClojureScript's
  cljs.repl/*, a Compliment-based completion variant, etc.) without
  having to fork Port.

Initial release.

• TCP prepl client with a small EDN-ish reader (handles maps, vectors, and lists with simple leaf values).
• Two-socket session model: a user socket drives the REPL with raw streaming output, and a separate tool socket carries helper-command requests with reliable request/response correlation via a small port.tooling/-eval bootstrap.
• M-x port jacks in: detects deps.edn / project.clj / bb.edn, picks a free port, spawns a JVM running a prepl server, polls until reachable, and connects. If a session is already active it just pops to the REPL, SLIME-style.
• Single-buffer REPL that renders :ret, :out, :err, and :tap messages. Eldoc, completion-at-point, and persistent input history are wired into the prompt; killing the REPL buffer disconnects the session.
• Persistent REPL input history. Each REPL buffer reads/writes <project-root>/.port-history (configurable via port-repl-history-file); M-p / M-n walk the history across sessions. Capacity is port-repl-history-size (default 1000) and adjacent duplicates are dropped.
• Interactive eval commands: last-sexp, defun-at-point, region, buffer. Values returned through the tool-socket path are pretty-printed via clojure.pprint, capped by port-print-length (default 50) and port-print-level (default 5). Multi-line results are truncated to the first line in the minibuffer; the full text appears in the REPL when port-eval-display is both.
• Helper commands powered by Clojure evaluation: doc, source, apropos, macroexpand-1, macroexpand, load-file, set-ns.
• Eldoc support: arglists for the function whose call surrounds point, resolved on the tool socket and delivered asynchronously via eldoc-documentation-functions.
• completion-at-point for symbols visible in the buffer's namespace, driven by a synchronous tool-socket request that walks ns-map.
• port-find-definition (bound to M-.) jumps to the source of the symbol at point using :file / :line from var metadata. When the source lives inside a jar, the file's contents are slurped over the tool socket and shown in a read-only *port-jar: ...* buffer.
• Structured stacktrace buffer (*port-stacktrace*): on :exception true (and on :tag :err from the tool socket) Port renders a concise one-line summary inline and pops a navigable buffer with the cause chain, ex-data, and a filtered trace. RET on a frame jumps to the source when the file resolves locally.
• port-mode minor mode for Clojure source buffers. No hard dependency on clojure-mode; hook it onto whichever Clojure mode you use (clojure-mode, clojure-ts-mode, or both).