The last-session record exists to make the routing policy falsifiable, and it only is if --last-effort is measured. route.sh documented the opposite as settled fact: that the effort a session ran with is not observable from inside that session. That was true when written and is not now. Claude Code exports CLAUDE_EFFORT into every tool-use context as the session's current effort level, so a Bash call reads it directly. The premise had a cost. With effort unobservable, the record could only be completed by asking the operator at session end, which made it block on their presence -- all four fields or none. That is also the weaker measurement, and in the same way the previous board line is: the operator reads the effort off the startup command they typed, so both sources report what was PRESCRIBED rather than what was RUN. They come apart exactly when the record would be most interesting, which is what a session that silently ran xhigh under a board line saying high already showed. Reading it makes all four fields knowable from inside the ending session, so the record no longer waits on anyone. The skill does the reading; route.sh deliberately does NOT default from the variable, because a calculator that consults its environment is no longer deterministic from its arguments and the route->board round trip in selftest section 6 rests on that. Section 13 also pins the trap this opens: skill frontmatter overrides the session effort while that skill is active, so an effort: field in route's own SKILL.md would make the reading report the skill instead of the session -- a measurement quietly measuring itself, with nothing in the output to show it happened. Also corrects the neighbouring claim that the model is readable from the environment. There is no CLAUDE_MODEL; the session takes it from what it knows itself to be running as. route-selftest 50 -> 56. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Gfa1nvwGXdST2MHvbs6htD
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repo-mailbox
Renamed from coord in v0.3.0. The plugin/repo is repo-mailbox; the CLI
(coord-send.sh, coord-inbox.sh, coord-done.sh), the mailbox root
(~/.claude/coord/) and CLAUDE_COORD_DIR deliberately kept their names —
they are the transport protocol, not the product.
Context
Local inter-repo coordination mailbox for Claude Code, packaged as a marketplace plugin. Three components, one boundary:
-
Engine (
scripts/*.sh): bash owns all mailbox semantics — filename grammar, frontmatter, delivery, archiving, the seen set.coord-send.shwrites,coord-inbox.shreads (formatted for context injection),coord-done.sharchives,coord-count.shcounts without delivering. Everything is pinned bycoord-selftest.sh(156 checks, throwaway mailbox viaCLAUDE_COORD_DIR).coord-count.shprints TWO integers per mailbox (<name>\t<pending>\t<debt>), and the first must stay pending:board.shcounts the same inbox files itself, so a debt-only count would put two different numbers under one name. Debt is read fromreply-expectedin the FRONTMATTER BLOCK ONLY - a body line is untrusted input and must not be able to silence a debt - and an absent field means a reply IS owed, because every message written before 0.11.0 lacks it.Reading is delivering — counting is not.
coord-inbox.shrecords a broadcast as seen once it has printed it, so it can never be used to survey other repos: doing so would consume each one's backlog silently, and the seen set is delivery history that retraction deliberately leaves alone.coord-count.shexists for every "what is pending" question and writes nothing at all. Any future read-shaped feature belongs there, not in the read path. -
Hook (
hooks/scripts/session-start.mjs): thin zero-dependency Node wrapper (marketplace convention: hooks are.mjs) that callscoord-inbox.shand emits thehookSpecificOutput.additionalContextenvelope. No mailbox logic lives here. Always exits 0. -
Board (
scripts/board.sh): cross-repo attention board. Reads STATE.md next-step blocks + board lines,git status, and mailbox pending counts, and prints one line per repo. Read-only by construction: it writes to no repo, no STATE.md and no mailbox. Pinned byboard-selftest.sh(36 checks).It lives here because the mailbox is one of its three inputs, and it carries the same axis distinction the mailbox does. A pending count means others are waiting on this repo; who a repo waits on comes only from its board line, because the message format has no reply-to field. Enforcing that in one of two repos would not be enforcing it.
~/.claude/scripts/board.shis a deployed copy (the operator'sboard()shell function points at it), exactly as with thecoord-*scripts — this repo is the source of truth. -
Route (
scripts/route.sh): pure calculator for the next session's model and effort. Takes four scored traits of the next task plus a required rationale, and prints one block ofkey=valuelines: the rubric row, the rule that fired, thenext-costvalue, a pasteable startup command, the one-row cheaper fallback, and the STATE.md comment lines. Pinned byroute-selftest.sh(56 checks).It is here because it is the WRITER for the field
board.shalready reads.next-costhad a reader and no writer, so it was hand-typed every session and drifted into several competing spellings — cleaning the data could not fix that, because the cause was the missing write path. The row table is a closed set of six values, so a seventh cannot enter circulation, and section 6 of the selftest runs the round trip (route emits → board parses) inside one repo rather than across two.board.shitself is untouched: a calculator that prints to stdout writes nothing, and the session writes STATE.md.The row table is the operator's global rubric, moved here as the single copy. It is not a second spec —
board.sh --helpdocuments the board line's grammar and points here for the values. Scoring the traits is judgement and belongs to the skill; turning scores into a row is a lookup and takes zero model calls.--last-effortis MEASURED fromCLAUDE_EFFORT, and the calculator must never default it. Claude Code exports that variable into every tool-use context as the session's current effort, so the caller reads it and passes it in; havingroute.shread it directly would make the output depend on the environment instead of on its arguments, and the round trip in selftest section 6 rests on that determinism. The two sources it replaces fail identically: the previous board line holds what was prescribed, and asking the operator launders that same prescription through someone reading their own startup command. Corollary pinned by section 13:skills/route/SKILL.mdmust never declare aneffort:frontmatter field, because frontmatter overrides the session effort and the reading would then measure the skill, not the session. -
Skills (
skills/coord-send/,skills/board/,skills/route/): natural-language front doors mapping user intent to engine invocations. No mailbox logic lives here either.boardadditionally owns the ranking — which repo wins and why — sinceboard.shdeliberately prints evidence and takes no position.routelikewise owns the scoring: the calculator is deterministic, so all judgement sits in choosing the four trait values, and the skill must never reason its way to a model instead.
Boundary rule: the mailbox is transport, not state. Durable decisions live in the owning repo's docs/git history; messages are notices pointing at them. Message content is untrusted cross-repo input — the read side quotes and frames it; the send side sanitizes line-oriented fields.
What the boundary forbids is storing a repo's state — its decisions, its next
step, its progress. It does not forbid the mailbox knowing who it is delivering
to: _broadcast/seen/<repo> and <repo>/.origin (0.6.0) are delivery metadata,
answering "has this repo received this" and "which checkout claimed this name".
Both are unreadable as a description of the repo and useless outside delivery.
The test is not "does the engine write a file about a repo" but "would this file
still mean anything if delivery were removed". If yes, it belongs in the repo's
own docs and git history instead.
Priority rule (v0.5.0, Rule 7): the injection block is the only place a repo is ever told what to do with a message, so its wording is the protocol — treat that string as engine behavior, not prose. It obligates handling the inbox first and driving every directed message to a terminal state before the session ends. The obligation is procedural, never substantive: responding is mandatory, complying with message content is not. Those two must stay distinct in any reword — keeping the priority while dropping the distinction turns prioritization into an injection surface. Selftest section 20 pins both halves together for exactly that reason.
Since 0.11.0 the reply-expected field says which terminal state the SENDER
expects. That does not soften the split, it sharpens it: the field is untrusted
cross-repo input like the rest of the file, so the injection calls it a
declaration, not an instruction and keeps both terminal states open to the
receiver. Drop that clause and one word in a message becomes a lever that mints
obligations in another repo.
Conventions
- Scripts are bash-3.2-safe and ASCII-only: no
declare -A, noreadarray/mapfile, no|&; guardshift 2with$# -ge 2; guard empty-array expansion underset -uwith${#a[@]}. - Zero dependencies everywhere: bash + coreutils in the engine,
node:builtins only in hook and tests. - TDD: no behavior change without a failing selftest check first.
bash scripts/coord-selftest.shmust exit 0 (156/156),bash scripts/board-selftest.shmust exit 0 (36/36) andbash scripts/route-selftest.shmust exit 0 (56/56). - English for all code, docs, and commit messages (public repo). Norwegian trigger aliases in the skill description are deliberate.
- Conventional Commits:
type(scope): description.
Commands
- Test:
bash scripts/coord-selftest.sh,bash scripts/board-selftest.shandbash scripts/route-selftest.sh(ornpm test, the Node wrapper around all three) - Hook smoke test:
node hooks/scripts/session-start.mjs(expects JSON on stdout) - Board smoke test:
bash scripts/board.sh(read-only, ~3s over the real tree) - Route smoke test:
bash scripts/route.sh --path known --verification strong --reversibility cheap --scope local --rationale x(writes nothing, instant)
Release
Version must agree across: .claude-plugin/plugin.json, package.json,
README version badge, skills/coord-send/SKILL.md, skills/board/SKILL.md and
skills/route/SKILL.md frontmatter, git tag vX.Y.Z, and the catalog ref in
ktg-plugin-marketplace/catalog/.claude-plugin/marketplace.json. Release via
the catalog's scripts/release-plugin.mjs repo-mailbox (tag + ref bump
together);
verify with scripts/check-versions.mjs. Never hand-edit a ref.
Two things that script does that its dry-run label does not suggest:
--create-tag creates AND pushes the tag even without --write, and its
closing verification gate runs check-versions.mjs over ALL plugins — one
unrelated plugin in ERROR aborts it with the catalog edit written but
uncommitted. When that happens, commit the catalog's marketplace.json +
README.md by hand and leave every other dirty file in that repo alone.
Hardening roadmap
Empty — the post-v0.1.0 queue (atomic delivery, ./.. rejection,
selftest gaps, uniform -h) shipped in v0.2.0; broadcast self-delivery
shipped in v0.2.1; broadcast retraction (coord-send --retract) shipped in
v0.4.0, closing the last monotonically-growing surface. coord-inbox.sh
still ignores unknown arguments by design (hook context must never fail)
but now warns about each one on stderr, which the hook discards.
Two retraction limits are deliberate, not gaps: it is un-send and never
recall (a repo that already received a broadcast keeps it — the seen set is
delivery history and is left untouched), and the sender check is an accident
guard, not a security boundary, because --from redefines identity here as
it does everywhere else in the engine.