This is an event-sourced ticket system that syncs with Jira through a reconciler pattern, letting Claude interact with your issue tracking through MCP. The event sourcing architecture means all ticket changes are stored as events rather than just current state, which is useful when you need audit trails or want to replay history. You'd reach for this when you want Claude to query, create, or update tickets while maintaining a local event log that reconciles with Jira. The stdio transport makes it straightforward to wire up locally. Good fit if you're already running Jira but want an event-sourced layer on top with LLM access baked in.
An event-sourced, git-backed ticket store + Jira reconciler built for agent swarms — one store, exposed as a Python library, a CLI, and an MCP server.
rebar), a Python
library (import rebar), or an MCP server (rebar-mcp).tickets git branch; no database, no daemon, and it travels with every clone.main
must pass an LLM code review and CI, on Gerrit, before it lands.pipx install nava-rebar # the `rebar` CLI (add [mcp] / [agents] for those extras)
brew install navapbc/rebar/rebar # or via Homebrew
Run one ticket end-to-end with the CLI or the Python library; the JSON block is the
MCP server config so agents can drive the same loop over MCP. rebar --help (and
rebar <command> --help) is the authoritative command reference.
# CLI: one ticket through init -> create -> ready -> claim -> close
rebar init
tid=$(rebar create task "Add a login page" | tail -1) # capture the new ticket id
rebar ready # lists it as ready to work
rebar claim "$tid" --assignee alice # open -> in_progress
rebar transition "$tid" in_progress closed # in_progress -> closed
import rebar # the same loop via the Python library
tid = rebar.create_ticket("task", "Add a login page")
rebar.claim(tid, assignee="alice")
rebar.transition(tid, "in_progress", "closed")
{ "mcpServers": { "rebar": { "command": "uvx", "args": ["--from", "nava-rebar[mcp]", "rebar-mcp"] } } }
That's the whole loop — init → create → ready → claim → close. The CLI and Python blocks each drive one ticket end-to-end (the same id threaded through every step, no hard-coded id); the JSON is the MCP server config — add it to your client so an agent can run the same loop via the MCP tools. State is shared through the repo so many agents (and teammates via Jira) coordinate without stepping on each other.
rebar stores tickets as an append-only event log on a dedicated tickets git
orphan branch (worktree at .tickets-tracker/); ticket state is computed by replaying
events, and every write auto-commits and pushes so the store is shared immediately. A
level-triggered reconciler bidirectionally syncs tickets with Jira. The branch name
and worktree dir are configurable (tracker.branch / tracker.dir — see
Configuration). Reads stay sub-second into the thousands of tickets;
for measured numbers and git-growth expectations see
docs/scale-envelope.md.
Documentation lives under docs/ — start with the
docs index (grouped by audience: user / operator / contributor /
agent) or the day-to-day user guide.
If you run coding agents against a repo, you eventually want to run several at once — and the moment you do, they need a shared place to coordinate. Most trackers weren't built for that:
rebar's answer is to make the tracker part of the repo. Tickets are an
append-only event log on a dedicated tickets orphan branch (linked in through a
gitignored worktree); current state is a fast, deterministic replay of that log.
That single decision pays off across the board:
claim is an
atomic, optimistic-concurrency primitive: agents grab work without stepping on
each other.On top of that foundation, rebar adds what parallel agent work actually needs:
next-batch hands parallel agents work that won't collide on the same files.discovered_from ties emergent work back to the ticket
that surfaced it.System prerequisites:
git — required (the store is a git orphan branch +
worktree). The engine is pure in-process Python; bash and jq are not
required at runtime.fcntl.flock(LOCK_EX)
advisory lock plus an atomic mkdir lock (src/rebar/_store/lock.py) — so there
is no dependency on util-linux's flock binary (or any other external tool).
The mkdir window keeps mutual exclusion holding even where fcntl.flock is
unreliable (e.g. some network filesystems).acli (Atlassian CLI) — only for
live Jira reconciliation.Python dependencies. A base install (pip install nava-rebar) — the rebar
CLI, the import rebar library, and the lean workflow engine — pulls only three
runtime dependencies: pyyaml (the workflow DSL loader),
jsonschema (the schema-registry +
workflow input/output-contract validator), and
referencing (the JSON Schema $ref
resolver jsonschema builds on); the engine core and reconciler are
otherwise stdlib-only. Everything else is an optional extra, lazy-imported so the
base stays light (CI enforces that):
[mcp] — the rebar-mcp server
(mcp>=1.9).[agents] — the LLM agent-operations framework + agentic workflow steps
(rebar review, the code_review workflow): the provider-agnostic
pydantic-ai runtime (pydantic-ai-slim[anthropic])
plus json-repair.[eval] — prompt evaluation (rebar prompt eval) with
Inspect AI; an authoring/CI capability.[tracing] — an OpenTelemetry OTLP trace sink
(write-only; never read back into a rebar decision), for diagnostics.[dev] — the test/lint/type tooling (pytest,
ruff, mypy,
hatchling). pip install -e '.[dev]' also
self-references [agents] so the validation tests run rather than skip, and
is required to run the full test suite (the interface-parity tests import the
MCP server, so they error — not skip — without mcp).src/rebar/llm/workflow/editor_assets/, the bpmn-js editor) and running the
faithful editor E2E tier (tests/e2e/, which drives the real bpmn-io
libraries). Both are developer-only — the built bundle is committed/shipped and
the E2E tier self-skips when Node is absent — so neither the base install nor the
default test suite needs Node. See docs/workflow-editor.md.rebar ships from one Python package — PyPI distribution nava-rebar (the
import package and commands stay rebar / rebar-mcp). Pick the channel that
fits. (System prerequisites in all cases: git and python3 (≥ 3.11); write
serialization uses a built-in fcntl.flock + mkdir lock with no external
binary; acli only for live Jira reconciliation.)
brew install navapbc/rebar/rebar
# or: brew tap navapbc/rebar && brew install rebar
Installs the rebar CLI (and the rebar library inside the formula's venv). For
the MCP server via Homebrew users, install the [mcp] extra with pipx/uvx below.
Runtime (prod) — install what you'll run:
pipx install nava-rebar # isolated CLI on PATH: rebar (+ lean workflow engine)
pip install nava-rebar # library: import rebar (runtime deps: pyyaml, jsonschema)
pip install 'nava-rebar[mcp]' # + MCP server: rebar-mcp
pip install 'nava-rebar[agents]' # + LLM agent ops + agentic workflow steps (rebar.llm)
pip install 'nava-rebar[eval]' # + prompt evaluation: `rebar prompt eval` (Inspect AI)
pip install 'nava-rebar[tracing]' # + OTLP trace sink (write-only)
pip install 'nava-rebar[agents,eval,tracing]' # the union, if you want it all
The base install runs scripted workflows (rebar workflow new/validate/show/run)
with no extra; agentic workflow steps and rebar review need [agents]. Authoring
a workflow visually — rebar workflow edit <file>, a local bpmn-js editor that
round-trips the diagram back to the IR — also needs no extra and no Node/npm: the editor
front-end ships pre-built in the wheel and is served locally (no CDN). For what the
engine is for — when to author a workflow vs a bespoke op, the YAML DSL, the
three-pass review pattern, and the prompt-library + eval seam — see
docs/workflow-engine.md; for visual editing specifically see
docs/workflow-editor.md.
The [agents] extra adds the optional LLM agent-operations framework
(rebar.llm) — tool-using agents that review tickets/code and emit structured
findings, over library / CLI (rebar review) / MCP. It is multi-provider
(Claude and ChatGPT out of the box, plus Gemini and OpenAI-compatible local
servers like LMStudio/Ollama via REBAR_LLM_MODEL/REBAR_LLM_MODEL_PROVIDER/
REBAR_LLM_BASE_URL) and is never required by core rebar — none of the LLM
stack is installed or imported unless you opt into this extra (CI enforces it);
see docs/llm-framework.md.
Listed in the MCP Registry as
io.github.navapbc/rebar. Registry-aware MCP clients can add it by that
name; or register it directly in your client config (zero pre-install via
uvx):
{
"mcpServers": {
"rebar": {
"command": "uvx",
"args": ["--from", "nava-rebar[mcp]", "rebar-mcp"],
"env": { "REBAR_ROOT": "/path/to/your/repo" }
}
}
}
(Already pip/pipx-installed nava-rebar[mcp]? Use "command": "rebar-mcp"
instead.) Server flags: REBAR_MCP_READONLY=1 exposes only read tools;
reconcile is dry-run unless REBAR_MCP_ALLOW_JIRA_SYNC=1. Both flags
accept any case-insensitive truthy value — 1, true, or yes (surrounding
whitespace tolerated); anything else (incl. unset) is off.
The LLM code-reading gates (review_plan, verify_completion, review_ticket,
review_code, scan_spec) default to attested mode: they git fetch the verified
ref from origin and read an immutable snapshot at the pinned SHA — never the server's
mutable checkout. So a server pointed (REBAR_ROOT) at a private repository needs
read credentials to fetch: a git credential helper, a deploy key, or a token in the
server's clone. With no credentials, attested mode fails closed with a descriptive,
actionable error (it never hangs on a prompt — GIT_TERMINAL_PROMPT=0); source=local
(read the in-place checkout, never signed) is the back-out that needs no fetch. Full
semantics, the HMAC trust model, and the snapshot env knobs (REBAR_GATE_TMPDIR, the
disk-space watermark, the EFS/NFS flock caveat) are in
docs/repo-snapshot-gates.md.
git clone https://github.com/navapbc/rebar && cd rebar
pip install . # library + CLI (runtime deps: pyyaml, jsonschema)
pip install '.[mcp]' # + MCP server (FastMCP)
# Developing rebar itself — the full dev environment (test/lint/type tooling +
# the agents stack so the LLM validation tests RUN, not skip):
pip install -e '.[dev]'
Contributing changes? GitHub is a read-only mirror —
mainonly advances via Gerrit's two-vote gate (LLM-Review+Verified/CI). New contributors: start with the friendly walkthrough docs/your-first-change.md; the full reference is CONTRIBUTING.md (clone from Gerrit, push torefs/for/main, then land it with a plain Gerrit Submit once both votes pass —mainis Rebase-If-Necessary, so Gerrit rebases onto the tip and submits server-side).
Packaging note — why rebar installs unpacked to disk. The library, CLI, MCP server, and the whole read/write core run in-process in Python. The one component that runs as a subprocess is the Jira reconciler, which ships under
src/rebar/_engine/as package data (python -m rebar_reconciler, plus thejira-capability-probe.pyscript and the alias wordlist): it is launched and read from the filesystem as real on-disk files, so the package must be installed unpacked to a real directory and zipimport / zip-safe bundles (zipapp, shiv, PEX, Lambda zips) are unsupported. Every standard install satisfies this: pip/pipx wheels (hatchling builds unpacked), editable installs, and Homebrew all land real files.engine_dir()asserts the engine dir is present on disk at the first reconciler call and fails loudly otherwise.
Advanced (optional) — gate commits with self-hosted code review. Not needed for standard rebar use. If you want every commit to
mainautomatically LLM-reviewed before it can land, you can self-host Gerrit + the rebar review-bot on AWS (the bot imports the samerebar.llmreview kernel the MCP server exposes) and demote GitHub to a read-only mirror that only advances via Gerrit after theLLM-Reviewvote passes. See docs/gerrit-aws-setup.md for the server setup. (This repo runs exactly that setup — see the contributor note above and CONTRIBUTING.md.)
The complete, always-current command reference — every subcommand with its
usage — is docs/cli-reference.md, generated from the CLI's
own help data (so it can never drift from the code). The essentials to get moving:
rebar init → rebar create <type> "<title>" → rebar ready → rebar claim <id> --assignee <you> → rebar transition <id> <current> <target>.
Run rebar help (or rebar --help / -h) for the subcommand overview, and
rebar <subcommand> --help (or rebar help <subcommand>) for a specific
subcommand's usage — --help prints usage and never executes the command.
Help is only recognized as the first argument after the subcommand, so a
--help/-h/help that appears inside a free-text parameter (title, comment
body, search query, …) is treated as literal text, not a help request.
Repo root is resolved from REBAR_ROOT, falling back to the git toplevel of the
working directory.
Structured output. Every data-returning command emits machine-readable JSON
via the canonical --output json flag (short -o json; --output llm gives a
token-minified shape for show/list/ready). Each distinct JSON shape is
documented by a JSON Schema and validated across the CLI, library, and MCP in CI.
See docs/output-schemas.md for the per-command contract
and the schema source-of-truth.
Repo-wide health with validate. rebar validate takes no ticket id — it
scans the whole store and prints an overall tracker-health score (1-5, exit 0-4)
bucketed into critical / major / minor / warning findings (--output json,
--terse, --verbose, --fix). Passing it a ticket id errors. (rebar also has
per-ticket structural gates that each take an <id> and verify a ticket is
shaped like dispatchable work — every type needs an ## Acceptance Criteria
checklist. See the ticket template and gate reference in
docs/plan-review-criteria-guide.md.)
Links. rebar link <id1> <id2> <relation> requires a relation; the six
relations are blocks, depends_on, relates_to, duplicates, supersedes,
discovered_from. rebar unlink <source> <target> takes no relation
argument — it is pair-scoped and removes the most-recently-created link
between that ordered pair, one per call, so to remove multiple links between the
same pair you call unlink repeatedly. Note that blocking links
(blocks/depends_on) may be promoted up the parent hierarchy when created (see
below), so unlink must target the promoted (ancestor) endpoint to remove
such a link.
Ticket work also leaves an HMAC-signed attestation — a machine-checkable proof that a gate ran and that its verified steps are unaltered. For most projects this is produced automatically by the code-review, plan-review, and completion-verifier gates, so you never sign by hand. To sign manifests yourself or customize the process, see docs/manifest-signing.md.
For blocking dependencies only (blocks, depends_on), rebar promotes the
link endpoints up the parent hierarchy so the dependency sits between tickets at
a comparable level (epic↔epic, story↔story, task/bug↔task/bug). When it does so
it emits a REDIRECT: A→B promoted to … note. Non-blocking relations
(relates_to, duplicates, supersedes, discovered_from) are linked exactly
as given, with no promotion.
Every rebar write (create, edit, transition, claim, link, …)
auto-commits its event to the tickets branch and auto-pushes that branch to
origin/tickets whenever an origin remote exists. Local ticket activity is
therefore shared with the remote immediately — including test/scratch tickets,
so be deliberate when working against a repo with a shared tickets remote. The
push is best-effort: with no origin remote nothing is pushed, and a push
failure (e.g. non-fast-forward it cannot auto-merge, or no network) never fails
the write — it leaves the local commit intact and the branch diverged.
rebar fsck reports PUSH_PENDING when the local tickets branch is ahead of
origin/tickets, so unpushed activity is observable. See
docs/concurrency.md for the push/merge-retry algorithm.
Running locally, offline, or read-only. This auto-sync is configurable when you
don't want the store talking to a remote (the full key set and env names are in
docs/config.md):
sync.push (env REBAR_SYNC_PUSH) — always (default) pushes each write
synchronously; async pushes in the background so per-write network latency
doesn't serialize a batch; off keeps commits local and never pushes (fsck
still surfaces PUSH_PENDING).sync.pull (env REBAR_SYNC_PULL) — on (default) lets reads fetch from the
remote (the freshness policy
below); off gives a pure-local replay (offline work, tight loops, or right after
a write that already synced). Pass --no-pull to a single read subcommand for the
same effect (e.g. rebar list --no-pull).mcp.readonly (env REBAR_MCP_READONLY=1) — serves only read tools over MCP,
so no writes — and therefore no commits or pushes — happen at all.How big can it get? Reads stay sub-second into the thousands of tickets; writes
are bounded by the per-event git commit (~25–30/s). See
docs/scale-envelope.md for representative measured
numbers, git-growth expectations, and the compaction/maintenance commands, and
docs/import-export.md for bulk NDJSON export/import.
Every read — show, list, ready, search, deps — first runs a
throttled (≤1/min), best-effort git fetch + reconverge of the local
tickets branch with origin/tickets, so a read reflects collaborators' pushes
within at most a minute. This is one contract shared by all three interfaces:
CLI, library (rebar.list_tickets(), …), and the MCP read tools all resolve
through a single read implementation. (Previously only CLI reads synced, leaving
MCP — the primary agent surface — with the stalest reads; that divergence is
gone.) To skip this fetch for a pure-local replay, set sync.pull=off or pass
--no-pull — see Running locally, offline, or read-only
above. Only the network fetch/merge is affected; the local reduce/cache path is
unchanged. See
docs/concurrency.md.
rebarThe tickets branch is rebar's internal storage format, not a document for
people to read. Each ticket is a directory of append-only JSON event files
(${hlc}-${uuid}-${TYPE}.json); the current state of a ticket is what you get by
replaying those events through the reducer. Two consequences follow:
EDIT/STATUS/TAG_DELTA
file in isolation tells you a delta, not the ticket..cache.json (gitignored).
Reading the raw files by hand will mislead you — a later event may supersede an
earlier one, a SNAPSHOT may fold many away, and concurrent forks resolve by a
deterministic rule you'd have to apply yourself.So don't cat the .tickets-tracker/ worktree to find out where a ticket
stands — use the read commands, which run the reducer for you: rebar show <id>, rebar list, rebar deps <id>, rebar search <query> (CLI), the matching
library calls (rebar.show_ticket(...)), or the MCP read tools.
For reference, docs/sample-ticket-log.jsonl is a
small synthetic event log (one event per line) showing what the underlying
data actually looks like — a two-agent epic + child tickets exercising
create/claim/comment/link/tag/file-impact/sign/transition. Note that its lines are
deliberately not in timestamp order: that is the point. The event body schema
is documented in docs/event-schema.md.
import rebar
rebar.init_repo(repo_root="/path/to/repo")
tid = rebar.create_ticket("story", "Add login page", priority=2)
ticket = rebar.show_ticket(tid) # TicketState
tickets = rebar.list_tickets(status="open") # list[TicketState]
try:
rebar.transition(tid, "open", "in_progress")
except rebar.ConcurrencyError:
... # ticket changed since last read
result = rebar.reconcile("dry-run") # Jira sync (non-mutating)
# Cryptographic attestation (environment-bound HMAC):
rebar.sign_manifest(tid, ["unit tests: PASS", "security review: clean"])
verdict = rebar.verify_signature(tid) # {"verified": True, "verdict": "certified", ...}
# Native, in-process reads (no subprocess):
from rebar import reduce_all_tickets, reduce_ticket
Typed return contract. The schema-backed rebar.* functions are annotated
with TypedDicts in rebar.types (e.g. TicketState,
TransitionResult, ClaimResult), so a type checker knows which keys a return
value carries. These are derived from the canonical JSON Schemas and describe the
guaranteed keys — returns stay plain dicts and the runtime shape is open
(extra keys may appear), so this is a floor, not a closed universe. Import them for
annotations/TypedDict access:
from rebar.types import TicketState, TransitionResult
t: TransitionResult = rebar.transition(tid, "open", "in_progress")
Stable exception surface. rebar.RebarError (base) and its subclass
rebar.ConcurrencyError are the public exceptions. RebarError carries
.returncode (the underlying engine exit code) and .stderr; ConcurrencyError
(exit 10) means a status-dependent op (transition/claim/reopen) lost an
optimistic-concurrency race — re-read and retry, don't force. Catch RebarError
to handle any rebar failure uniformly.
What's stable to depend on. rebar is versioned 0.x; see
docs/api-stability.md for the per-surface stability
matrix (CLI, --output json schemas, the rebar.* facade, MCP tools, the event
wire format, and config keys) and what "may change before 1.0" means for each.
rebar-mcp # stdio transport
Exposes ticket operations as MCP tools. The complete tool reference, grouped by
gate tier (read-only / LLM-gated / write-gated), is
docs/mcp-reference.md (generated from the server's own
registrars). reconcile defaults to dry-run (live requires
REBAR_MCP_ALLOW_JIRA_SYNC=1). Set REBAR_MCP_READONLY=1 to expose only the read
tools (no write/mutation tools). To register it in an MCP client (registry name
io.github.navapbc/rebar, or a direct uvx config), see
Install → MCP server above.
Maintainers: the registry manifest lives in server.json;
publish/update it with the mcp-publisher CLI (see docs/releasing.md). The
registry verifies PyPI-package ownership via this annotation (kept in this
README, which is the PyPI long description):
mcp-name: io.github.navapbc/rebar
Apache-2.0 — see LICENSE.
rebar reads TOML config from [tool.rebar] in pyproject.toml or a standalone
rebar.toml (nearest up-tree, stopping at .git), falling back to a user config at
~/.config/rebar/config.toml (honoring $XDG_CONFIG_HOME). Precedence, highest
first: rebar -c SECTION.KEY=VALUE / CLI flag > REBAR_<SECTION>_<KEY> env >
project config > user config > built-in default. rebar config prints the resolved
values and which layer each came from.
[tool.rebar]
verify.require_completion_verification_for_close = true # gate work-ticket close on a PASS
# completion verdict (signed onto the ticket);
# fail-closed. Default false.
ticket.display_mode = "auto" # auto | canonical | alias | short
compact.threshold = 10
sync.push = "always" # always | async | off
sync.pull = "on" # on | off
mcp.readonly = false
scratch.base_dir = "" # default <repo>/.rebar/scratch
tracker.dir = ".tickets-tracker" # store worktree/symlink dir (env REBAR_TRACKER_DIR)
tracker.branch = "tickets" # orphan branch the event log lives on (env REBAR_TRACKER_BRANCH)
The full key set, the REBAR_<KEY> env names, and deprecation aliases are in
docs/config.md.
When the close gate is enabled, closing a story/epic requires a certified
signature made at the current HEAD — sign a manifest of verified steps
(rebar sign <id> '[...]') then rebar transition <id> closed; re-sign if HEAD
moved, or bypass with --force-close=<reason>.
rebar keeps its writable state under .rebar/ at the repo root. The scratch
store defaults to <repo>/.rebar/scratch/ (override with scratch.base_dir /
REBAR_SCRATCH_BASE_DIR), and one-shot migration stamps are written under
.rebar/ as well.
Run the suite from an environment with the [dev] extra installed (a venv is
recommended); the interface-parity tests import the MCP server, so a bare
interpreter without the mcp extra will error rather than skip.
python -m venv .venv && source .venv/bin/activate
pip install -e '.[dev]' # editable + pytest, mcp, ruff, mypy
pytest -m "not integration" # the single entry point (CI runs this)
pytest tests/interfaces # interface-parity tier only
pytest tests/scripts # engine/reconciler tier only
pytest is the single entry point. The engine is pure in-process Python
(the bash engine and its .sh suites were removed in the bash→Python migration —
see docs/bash-migration.md). CI (.github/workflows/test.yml) runs
pytest -m "not integration" on
Ubuntu and macOS for every push and PR. The integration tier (live Jira /
network) is excluded from that default run; run it explicitly with credentials
via pytest -m integration.
The Python suite is sub-divided by concern:
tests/scripts, tests/unit — the in-process engine (reducer, graph, reconciler).tests/interfaces — proves the library, CLI, and MCP interfaces behave
identically over one git-backed store:
test_parity.py runs each operation through all three interfaces (and a
cross-interface coherence check: write via one, read via the others);test_surface.py pins the per-interface capability surface (e.g. MCP has no
init; there is no classify);test_library.py / test_cli.py / test_mcp.py cover per-interface
specifics (typed exceptions, exit-code passthrough, read-only/live gates).REBAR_ROOTPath to the repo root that holds the .tickets-tracker store (defaults to the git toplevel of the working dir).
REBAR_MCP_READONLYSet to 1 to expose only the read tools (no write/mutation tools).
REBAR_MCP_ALLOW_RECONCILE_LIVESet to 1 to allow the live (mutating) Jira reconcile mode; otherwise reconcile is dry-run only.
ray0907/git-mcp-server
cyanheads/git-mcp-server
io.github.b1ff/atlassian-dc-mcp-bitbucket
io.github.b1ff/atlassian-dc-mcp-jira
com.mcparmory/atlassian-jira
sirlordt/vscode-terminal-mcp