# Breadcrumbs

> Repo-local, agent-agnostic project memory — your AI agents remember decisions, avoid repeated failures, and resume where they left off

- **Type:** MCP server
- **Install:** `agentstack add mcp-jr-mccoy-breadcrumbs`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [jr-mccoy](https://agentstack.voostack.com/s/jr-mccoy)
- **Installs:** 0
- **Category:** [Integrations](https://agentstack.voostack.com/c/integrations)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [jr-mccoy](https://github.com/jr-mccoy)
- **Source:** https://github.com/jr-mccoy/breadcrumbs

## Install

```sh
agentstack add mcp-jr-mccoy-breadcrumbs
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Breadcrumbs

**Breadcrumbs — leave a trail your future self and your agents can follow back.**

A portable, repo-local, human-readable ledger of durable project state for
human–agent software work (the **Project Continuity Memory** capability).

> **North-star.** Project Continuity Memory is a repo-local, human-readable ledger
> of durable project state: what was decided, what failed, what is active, what is
> risky, what is unresolved, and what the next agent or human must know before
> acting. It is **not** a transcript archive, **not** a vector database, and **not**
> a replacement for source code, tests, current human instruction, or authoritative
> docs.

It stores durable project state as typed, human-readable records inside a target
project's `.project-memory/` directory, so humans and agents can resume work across
sessions, tools, devices, branches, and time without re-discovering decisions,
repeating failed attempts, or trusting stale context.

- **PyPI package name:** `crumb-kit` (`pip install crumb-kit`)
- **Import package / GitHub repo:** `breadcrumbs`
- **CLI binary name:** `crumb`
- **Formal capability name:** Project Continuity Memory

---

## Non-goals

This tool deliberately does **not**:

1. Build a vector database as the source of truth (vectors are a later, disposable
   search accelerator).
2. Store full chat transcripts as memory (it extracts durable decisions, attempts,
   handoffs, questions, traps, and evidence).
3. Rely on one vendor's memory feature (Claude, Codex, Cursor, Gemini, and future
   agents all read the same plain records).
4. Require MCP, hooks, or a daemon for baseline functionality (plain files + CLI
   work first).
5. Use `AGENTS.md` / `CLAUDE.md` / Cursor / Gemini rules as the memory database
   (those are signposts only).
6. Store secrets, credentials, customer PII, or sensitive local notes in committed
   project memory.
7. Make capture so heavy that humans stop using it (routine capture targets under
   90 seconds).

---

## Install

`breadcrumbs` is a stdlib-only Python package (no third-party runtime
dependencies) that installs a single `crumb` binary. The recommended path
is [`pipx`](https://pipx.pypa.io/), which puts the CLI on your PATH in its own
isolated environment:

```bash
pipx install crumb-kit   # from PyPI
pipx install .           # from a source checkout (this repo dir)
```

Plain `pip` works too (prefer a virtualenv):

```bash
python -m pip install .              # or: pip install .whl
```

After install, the binary is on PATH and the `.project-memory/` template tree
ships **inside the package** (`breadcrumbs/templates/`), so `init` finds it
wherever the package lives — there is no repo-relative path dependency:

```bash
crumb --version                 # breadcrumbs X.Y.Z (record schema_version N)
crumb init                      # locates bundled templates post-install
```

**Versioning.** The package uses semantic versioning. `crumb --version`
prints the package version *and* the **record `schema_version`** (the manifest's
`schema_version: 1`). These are independent: the package version moves with the
code; the record schema version moves only on a breaking change to the on-disk
record format, and a package MAJOR bump accompanies it.

**Requires** Python ≥ 3.9.

### No `npx` (deliberate)

There is intentionally **no `npx`/Node distribution**. The tool is Python and
ships via `pipx`/`pip`. JavaScript-ecosystem reach (an `npx crumb` wrapper)
is a separately-justified future decision, **not** a default migration — it would
only be added if dogfooding shows a concrete need, and would wrap the same Python
core rather than reimplement it.

---

## Quickstart

> **Two invocation forms.** Once installed (above), run `crumb `.
> From a **source checkout** without installing, the equivalent is
> `python crumb.py ` (a thin shim over `breadcrumbs.cli`); the
> per-command examples below use that source form. They are interchangeable.

```bash
crumb init                       # install .project-memory/ + manifest + .gitignore rules
crumb init --with-adapter --with-mcp --with-hooks   # ...and wire it into your agent (see Integrations)
crumb validate                   # deterministically check the store (schema + invariants)
crumb schema                     # print the record contract (sections, vocab, rules)
crumb remember decision          # capture a durable choice
crumb verify "finding#1" --status fixed   # record a verification result (a finding about reality)
crumb mark-status "dec_…" stale --reason "superseded by reality"   # record lifecycle mutation
crumb mark-status "trap_…" stale --reason "fixed in 2.1"           # ...retire a trap the same way
crumb mark-status "q:…" answered --reason "see dec_…"              # ...and answer an open question
crumb note question|trap|idea    # leave a note for the next agent (no hand-editing)
crumb capture session            # record session end (git-prefilled); updates handoff + current
crumb resume                     # print a bounded resume packet with computed staleness
crumb reindex                    # rebuild generated/ projections (mutations reindex automatically)
crumb search "auth middleware"   # deterministic keyword/tag/file lookup over records
crumb guard "rewrite the auth middleware"   # warn before repeating a known mistake
crumb audit                      # heuristic health/safety report (stale/unsafe/bloated)
crumb scan-secrets               # block if committed memory holds token-like strings
crumb doctor                     # is memory actually wired into your agent?
crumb mcp serve | register | doctor   # run / register / health-check the optional MCP server
```

In this build, `init`, `validate`, `remember`, `capture session`, `resume`,
`search`, `guard`, `audit`, and `scan-secrets` are all implemented — the full
**MVP** (capture → resume → trust). `resume` closes the **capture → resume value
loop (MVP-core)**; `guard` adds the **"don't repeat the expensive mistake"**
capability that separates a continuity engine from a scrapbook; and `audit` +
`scan-secrets` complete **MVP-trust** — the heuristic safety net (secrets,
instruction-like text, generated-packet drift, staleness, bloat) that lets you
*trust* the memory, not just use it.

### `crumb init`

```bash
python crumb.py init                                   # prompt for session policy (default: full)
python crumb.py init --session-tracking distillate     # keep sessions/ local
python crumb.py init --no-commit-generated             # keep generated/*.md local
python crumb.py init --project /path/to/repo --json    # init elsewhere, JSON summary
python crumb.py init --force                           # replace an existing scaffold (DELETES all records)
```

`init` copies the `.project-memory/` template tree into the target project,
writes `manifest.yml` (recording the chosen tracking policies), and inserts a
managed block into the project `.gitignore`. It runs on non-git folders too,
printing a notice that git-derived record fields will use defined sentinels.

On a terminal, `init` also offers to wire the store into your agent (inject a
signpost into `CLAUDE.md`/`AGENTS.md`, register the MCP server, install hooks).
Default non-interactive `init` touches none of those and prints a one-line nudge.
See **Integrations** below; flags: `--with-adapter`/`--with-mcp`/`--with-hooks`
(and `--no-*`), `--print-integrations` (dry run), `--remove-integrations`.

Running `init` with any integration flag against a project that **already has**
a `.project-memory/` store applies just those integrations and leaves the store
untouched — no `--force` needed (and none should be used: `--force` replaces the
scaffold and deletes all existing records).

### `crumb validate`

```bash
python crumb.py validate                      # human-readable report; exit 1 on problems
python crumb.py validate --json               # structured findings + exit code
python crumb.py validate --verbose            # also list the passing checks
python crumb.py validate --project /path/repo # validate elsewhere
```

`validate` is **fully deterministic** — it checks structural invariants only
(manifest version, core files, record frontmatter, filename-canonical identity,
status/privacy vocabularies, evidence/handoff/session requirements, generated
markers). It performs **no** heuristic content scanning; secret and
instruction-like-text detection live in `audit` / `scan-secrets`. Exit codes: `0`
clean, `1` problems found, `2` no `.project-memory/` store present.

### `crumb remember decision | attempt`

```bash
# non-interactive (agent-friendly): title + sections + evidence as flags
python crumb.py remember decision \
  --title "Use repo-local Markdown as source of truth" \
  --set Context "needed a tool-independent store" \
  --set Decision "Markdown + YAML frontmatter" \
  --evidence commit abc1234 --evidence command "npm test" \
  --tags memory,architecture

python crumb.py remember attempt --title "Tried a sqlite store" \
  --set Result "too heavy for the value" --confidence low
```

Frontmatter is auto-derived (clock + git) and defaulted; you supply only a title
and a few section lines (`--set HEADING TEXT`, repeatable). Run with no `--title`
in a terminal for an interactive prompt. A decision/attempt **must** carry
evidence or `--confidence low` (validate §16.9) — the command enforces this and
refuses to write an invalid record. `--json` emits a machine summary.

`remember attempt` also accepts the fixed attempt vocabulary as **named flags**
(`--problem`, `--tried`, `--result`, `--why`, `--do-not-retry`, `--related`), so
the contract is visible in `--help` instead of discoverable only by rejection.

Titles can be as long as you like; **filenames can't**. The slug in
`.project-memory//-.md` is capped at 60 characters (cut on a
word boundary, `-2`/`-3` collision suffixes included in the budget), so a
sentence-length title never produces a sentence-length path. That keeps a store
clonable on Windows, where the whole path is capped at 260 characters unless
`core.longpaths` is on, and stops long titles from tripping Linux's 255-byte
per-name limit. The full text stays in the record's `title` frontmatter, so
nothing is lost. Records already on disk with longer names keep working — the
cap applies when a name is generated, never when one is read.

The record's `agent` frontmatter says who wrote it. Without `--agent`, the CLI
reads the environment (`CLAUDECODE`, `CURSOR_AGENT`, `CODEX_SANDBOX`, …) and
records the harness it finds, or **`unknown`** when it finds none — it will not
claim a human wrote a record just because the flag was missing. Pass
`--agent human` to make that claim explicitly.

### `crumb verify`

```bash
python crumb.py verify "perf-audit-2026-05-15#F1" \
  --status fixed --method static \
  --evidence file app/DoWhatApplication.kt:170 \
  --note "DB validation moved to applicationScope.launch(ioDispatcher)"
```

Records a **verification result** — "I checked X; here is its state" — the most
common agentic output in maintenance, audits, and "is this bug still real?" work.
Without a home for it, agents either drop it or mis-file it as a decision/attempt
and pollute those categories. `--status` is the outcome
(`fixed|open|regressed|not_applicable|inconclusive`); `--method` is
`static|runtime|test`. Like a decision/attempt it needs evidence or
`--confidence low`. Verifications surface in the resume packet's **Verifications**
section (actionable outcomes first) and are searchable with `crumb search --type
verification --status open` (here `--status` filters on the outcome). Mirrored
over MCP as `memory_verify`.

### `crumb schema`

```bash
python crumb.py schema                       # the full record contract (human)
python crumb.py schema attempt --json        # one record type, machine-readable
python crumb.py schema attempt --template    # a copy-pasteable `remember` skeleton
```

`schema` prints the record contract — body sections per type, required/derived
frontmatter, status/privacy/confidence vocabularies, and the evidence-or-low-
confidence rule — straight from the source constants, with no `.project-memory/`
required. `--template ` emits a fill-in command so an agent reads the
contract once instead of probing `--help` repeatedly.

### `crumb note question | trap | idea`

```bash
python crumb.py note question "Should age signals gate compliance?" --why "blocks export"
python crumb.py note trap "gradlew --stop corrupts R.jar lock" --area build --safe "kill by pid"
python crumb.py note idea "cache the resume packet" --set Idea "memoize across sessions"
```

`note` is the write-surface for the three record kinds that previously had no
command: open questions, known traps, and ideas. `question`/`trap` append a
parse-verified block to `open-questions.md` / `known-traps.md`; `idea` writes a
validated record under `ideas/`. Each refreshes `generated/resume-packet.md` so
the projection never lags the note. Mirrored over MCP as the `memory_note` tool.

### `crumb capture session`

```bash
python crumb.py capture session --next "wire up the resume packet"   # git-prefilled
python crumb.py capture session --fast --next "tired — resume here"    # ~15s, no prompts
```

`capture session` reads git since the last session record and pre-fills **Work
Completed** (`git log`), **Files Touched** (a one-line `git diff --shortstat`
summary — `N files changed, +X/-Y`, not an inlined per-file list, so records stay
small and the secret scanner never trips on path-shaped tokens), then asks only
for narrative confirmation + a required **Next Action**. It writes the session record
and refreshes `handoff.md` and `current.md`. `--fast` skips all prompts and any
LLM, writing a git snapshot + the one-line `--next`. No path requires an LLM.

The bare form prompts, so it needs a terminal. **To run it unattended**, supply
every section you want on the command line — `--next` plus `--set ""
""` for each narrative heading. That keeps the git prefill, unlike `--fast`,
which drops narrative entirely:

```bash
crumb capture session --next "wire the parser" \
  --set "Decisions Made" "kept the projection rebuild on the write path"
```

The prefill window is bounded: `since..HEAD` from the newest session record's
commit, or — when that is more than 20 commits back, or there is no prior record —
the last 20 commits. Either way the record names the window it used, so a large
diff can be read for what it is instead of taken as one sitting's work.
With `session_tracking: distillate`, the session file is written locally but stays
gitignored — promote durable items with `remember` to commit them.

### `crumb resume`

```bash
python crumb.py resume                       # full bounded packet (writes generated/resume-packet.md)
python crumb.py resume --fast                # git snapshot + focus + next action + staleness (print-only)
python crumb.py resume --json                # structured packet (sections + warnings) for agents
python crumb.py resume --stale-days 14       # tighten the age cutoff (default 21)
python crumb.py resume --task "verify the perf audit"   # scope likely-files to matching records (print-only)
```

`resume` assembles a **bounded, paste-anywhere packet** (≤5k tokens) from the
canonical records — project/branch/commit, current focus, next action, active
decisions (id + one-line rationale), failed attempts to avoid (id + do-not-retry),
known traps, open questions, likely files, verifications (recorded results,
actionable outcomes first), and verification commands — followed by
**computed staleness warnings**:

- handoff **age + commit-distance** ("handoff is 6 days old, written 14 commits
  behind current HEAD") — the primary "train of thought went cold" signal, carried
  in `--json` as `handoff_age_days` / `handoff_commit_distance`, separately from the
  `stale_after_days` threshold they are compared against;
- **aged-unresolved** open questions and active decisions older than the

…

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [jr-mccoy](https://github.com/jr-mccoy)
- **Source:** [jr-mccoy/breadcrumbs](https://github.com/jr-mccoy/breadcrumbs)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/mcp-jr-mccoy-breadcrumbs
- Seller: https://agentstack.voostack.com/s/jr-mccoy
- Browse the marketplace: https://agentstack.voostack.com/browse

---
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