markstay 0.1.0

Python reference implementation of the markstay spec (v1.1): source-level block identity for Markdown

markstay , Python reference implementation (v1 core)

The Python reference implementation of the markstay spec (v1.1). markstay is a source-level identity primitive for Markdown blocks: an id token that stays bound to its block across edits (marker stay:), so a reference to a block survives the document being rewritten, including by an LLM.

This is the parser-free core: everything string-level and parser-independent (§8 hashing, §3/§4 marker grammar, §5 blank-line segmentation, §7/§11 lint, §9 quote recovery, §9.1 resolution ladder). It mirrors the JavaScript reference (markstay on npm); both are gated by a shared language-neutral conformance corpus, which turns "two implementations agree" from an assertion into a tested fact.

Install

pip install markstay

Zero runtime dependencies (Python standard library only). CommonMark-tree segmentation (§5.2) is an optional extra:

pip install "markstay[commonmark]"   # pulls in markdown-it-py

Requires Python >= 3.9.

Library

import markstay as M

md = "The ingest stage retries three times.\n<!-- stay:a1b2 -->\n"

# parse into content blocks with attached markers (§5)
blocks = M.parse_document(md)

# well-formedness + intra-doc invariants (§7): duplicate/orphan/malformed/drift
_, findings = M.lint_document(md)

# regeneration diff (§11): what an edit did to the ids (dropped/duplicated/moved)
findings = M.lint_diff(before_md, after_md)

# §8 content hash (ASCII-normalized SHA-256)
M.body_hash("some block body")

# §9.1 resolution ladder: re-attach ids after an edit, or report DETACHED
anchors = M.build_anchors(before_md)
resolutions = M.resolve(anchors, after_md)   # id -> marker | hash | quote | detached

Public API (mirrors the JS index.js surface): normalize_body, body_hash, Marker, find_markers, strip_markers, segment_blank_line, segment_commonmark, Block, parse_document, Finding, lint_document, lint_diff, sort_findings, has_errors, Selector, normalize, body_score, context_bonus, best_match, CONTEXT_CHARS, Anchor, Resolution, build_anchors, resolve, DEFAULT_THRESHOLD, DEFAULT_MARGIN.

CLI

markstay FILE [FILE ...]            # well-formedness + intra-doc checks
markstay --before OLD.md NEW.md     # regeneration diff (dropped/duplicated/relocated ids)
markstay --json ...                 # machine-readable findings
markstay --commonmark ...           # §5.2 CommonMark-tree segmentation (needs the extra)

Exit status is non-zero when any error-level finding is reported, so it can gate a commit hook or an agent's post-edit step.

The conformance corpus (the actual deliverable)

The corpus under conformance/ is shared with the JavaScript reference. 276 vectors across two tiers:

• spec/ , hand-authored from the spec prose, asserting what the words require. These are authority; a spec/ vector the reference fails is a reference bug, not a corpus error.
• gen/ , emitted from the reference for breadth/regression.

The JS reference runs the same JSON, so the two runners are a cross-impl regression sentinel: any later change to either implementation that breaks agreement fails one of them.

Running the tests

pip install -e ".[commonmark]"
pytest

License

MIT