Breadcrumbs

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

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Non-goals

This tool deliberately does not:

1. Build a vector database as the source of truth (vectors are a later, disposable

search accelerator).

1. Store full chat transcripts as memory (it extracts durable decisions, attempts,

handoffs, questions, traps, and evidence).

1. Rely on one vendor's memory feature (Claude, Codex, Cursor, Gemini, and future

agents all read the same plain records).

1. Require MCP, hooks, or a daemon for baseline functionality (plain files + CLI

work first).

1. Use AGENTS.md / CLAUDE.md / Cursor / Gemini rules as the memory database

(those are signposts only).

1. Store secrets, credentials, customer PII, or sensitive local notes in committed

project memory.

1. Make capture so heavy that humans stop using it (routine capture targets under

90 seconds).

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Install

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

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

Plain pip works too (prefer a virtualenv):

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:

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.

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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.

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

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

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

# 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

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

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

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

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:

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

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
• Source: jr-mccoy/breadcrumbs
• License: MIT

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