[PROPOSAL] governance-mcp: read-only substrate access for the jurist (PENDING-82)

The three-party model asks Claude.app to rule on items it cannot read. Steward
confirmed 2026-07-28 that local MCP servers are exposed to the app's *chat*
surface — and always have been, predating Cowork by about a year. My earlier
framing ("chat, not only Cowork") had the relationship backwards: it is "chat,
always; Cowork, only while its loop still runs locally," and local Cowork is the
mode being phased out as default. The jurist chat is therefore the sturdy target.

Five read-only tools. The one a pasted cache can never provide is
governance_item(id): the verbatim body of any item or ruling, across PENDING.md,
PENDING-archive.md and REVIEWED.md. Four refusals are designed in, each with a
control proving the refusal is detectable — no writes (AST-audited), no path
arguments (keys from a fixed enum, so there is no traversal to defend), no second
parser (item_spans is imported, not reimplemented), and not an agent (tools
return data; an agent would return testimony about the substrate instead).

[FIX] to the shared definition while here: item_spans() is now fence-aware. A
'## ' header inside a fenced block is neither an item nor a boundary. Zero such
headers exist today — 17 open items before and after — but governance drafts are
written as fenced markdown carrying '## REVIEWED-N' headers, which is the
steward's own practice, so the next draft would have created a phantom item and
truncated the item containing it. PENDING-82's own fenced JSON block confirms the
fix within the hour.

Not installed. The mcpServers key edits the steward's desktop-app config; the
snippet is in PENDING-82 and the server is inert until someone loads it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WuMjg3ipEVa3n8CoSzoyvc
This commit is contained in:
David F Glidden
2026-07-28 10:20:17 +02:00
co-authored by Claude Opus 5
parent d12feb5ba9
commit 3df09228c0
4 changed files with 516 additions and 9 deletions
+422
View File
@@ -0,0 +1,422 @@
#!/usr/bin/env python3
"""governance-mcp — read-only MCP server giving the jurist eyes on the substrate.
WHY THIS EXISTS
The three-party model asks Claude.app (jurist) to rule on governance items it
cannot read. Its reader has no filesystem, so until now its picture of PENDING /
REVIEWED / drift could only be *cached* — pasted in by the steward and stale from
the moment it landed. `wake-digest.py --brief` narrows that gap; it does not close
it, because a snapshot cannot answer a question nobody anticipated.
This closes it for Claude.app's **chat** surface, where local MCP servers have
always been exposed (steward-confirmed 2026-07-28). Cowork gets local MCP only
while its agent loop still runs on-device — the mode being phased out as default —
so a Cowork-dependent design would have been the fragile one.
WHAT IT REFUSES TO BE
- **Read-only.** No tool writes, moves, or deletes. The jurist proposes; the
steward authorizes; the executor acts. An MCP write path would collapse three
parties into one.
- **Not an agent.** Every tool returns *data*, verbatim where possible. The
alternative considered and rejected was a second Claude with filesystem access
reporting back: that yields an agent's testimony about the substrate, not the
substrate. A tool returns data; an agent returns a claim.
- **No second parser.** "Open item" is defined ONCE, in wake-digest.py, imported
here. On 2026-07-28 a splitter's private definition of "item" hid twenty items,
ten of them open, and every check inherited the blind spot. Two implementations
of one field is that failure waiting to recur across a boundary nobody watches.
- **No path arguments.** Every tool takes a KEY from a fixed enum, never a path.
There is no traversal to defend against because there is no path to traverse —
and the reachable domain is enumerable rather than defined by the instrument.
governance-mcp.py --selftest exercise every tool, presence AND absence
governance-mcp.py --stdio serve (how the app launches it; also the default)
Provenance: 2026-07-28, on PENDING-81's MCP leg. Sibling of wake-digest.py and
governance-drift-check.py; imports the first.
"""
import importlib.util
import json
import os
import subprocess
import sys
import time
HOME = os.path.expanduser("~")
D = os.path.join(HOME, "dotfiles")
SCRIPTS = os.path.join(D, "scripts")
NAME, VERSION = "governance", "1.0.0"
# Newest protocol we speak; we echo the client's version when it sends a known one.
PROTOCOLS = ("2025-06-18", "2025-03-26", "2024-11-05")
def _load(mod_name, filename):
"""Import a sibling script whose filename is not a valid module name."""
spec = importlib.util.spec_from_file_location(mod_name, os.path.join(SCRIPTS, filename))
m = importlib.util.module_from_spec(spec)
spec.loader.exec_module(m)
return m
wd = _load("wake_digest", "wake-digest.py") # the single definition of "open item"
# ---- the enumerated domain: keys, never paths -------------------------------
FILES = {
"pending": (os.path.join(D, "PENDING.md"), "open authorization items"),
"pending-archive": (os.path.join(D, "PENDING-archive.md"), "closed authorization items"),
"reviewed": (os.path.join(D, "REVIEWED.md"), "steward/jurist decisions"),
"claude-md": (os.path.join(D, "CLAUDE.md"), "the executor's governing document"),
"memory-index": (os.path.join(wd.MEM, "MEMORY.md"), "wake-loaded memory index"),
"app-brief": (wd.BRIEF_PATH, "last generated .app Standing Context block"),
}
REPOS = wd.REPOS
def read(path):
try:
return open(path, encoding="utf-8").read()
except Exception as e:
return None if isinstance(e, FileNotFoundError) else None
# ---- tool implementations (pure-ish; selftest exercises these directly) -----
def t_state(_args):
"""The whole picture, computed now: open items with tags, recent rulings, drift, repos."""
wd.warn.clear()
items, revs, drift, repos = wd.sec_pending(), wd.sec_reviewed(6), wd.sec_drift(), wd.sec_repos()
o = [f"GOVERNANCE STATE — computed {time.strftime('%Y-%m-%d %H:%M')} local, not cached.",
"",
f"OPEN AUTHORIZATION ITEMS ({len(items)}) — full body via governance_item(id=…)"]
for h, ln, tag in items:
o.append(f" {tag:<14} {h} [{FILES['pending'][0].rsplit('/', 1)[1]}:{ln}]")
o.append("\nRECENT RULINGS")
for h, d in revs:
o.append(f" {d:<11} {h}")
o.append(f"\nGOVERNANCE DRIFT — CLAUDE.md: {drift} substrate-contradicted claim(s)."
" Detection only; correcting doctrine requires [ESCALATE]. Detail via drift_report().")
o.append("\nREPOS (branch · uncommitted files · last subject)")
for r, head, dirty, subj in repos:
o.append(f" {r:<24} {head:<32} {dirty:>3} dirty {subj}")
if wd.warn:
o.append("\n⚠ DEGRADED — these could not be computed (treat as unknown, not as clean):")
o += [f" - {w}" for w in wd.warn]
return "\n".join(o)
def t_item(args):
"""Verbatim body of one PENDING/REVIEWED/COMPLETED item, wherever it lives.
Item boundaries use the same rule as wake-digest: an item starts at any '## '
header and ends at the next one. No family regex — that is the 2026-07-28 bug."""
ident = (args.get("id") or "").strip()
if not ident:
return "ERROR: id is required, e.g. 'PENDING-81' or 'REVIEWED-80'."
for key in ("pending", "pending-archive", "reviewed"):
text = read(FILES[key][0])
if text is None:
continue
lines = text.split("\n")
for head, start, end in wd.item_spans(text):
if head == ident or head.startswith(ident + " "):
return (f"[{ident} — verbatim from {os.path.basename(FILES[key][0])}, "
f"line {start}]\n\n" + "\n".join(lines[start - 1:end - 1]).rstrip())
return (f"NOT FOUND: no '## {ident}' header in PENDING.md, PENDING-archive.md, or "
f"REVIEWED.md. Use governance_state() to list open items by id.")
def t_read(args):
"""Verbatim paged read of one enumerated file. No path argument by design."""
key = (args.get("file") or "").strip()
if key not in FILES:
return ("ERROR: unknown file key %r. Allowed: %s"
% (key, ", ".join(f"{k} ({d})" for k, (_p, d) in FILES.items())))
path, desc = FILES[key]
text = read(path)
if text is None:
return f"UNREADABLE: {key} ({desc}) is absent or unreadable at this time."
lines = text.split("\n")
off = max(0, int(args.get("offset") or 0))
lim = max(1, min(int(args.get("limit") or 400), 2000))
chunk = lines[off:off + lim]
more = ("" if off + lim >= len(lines) else
f"\n\n[… {len(lines) - off - lim} more lines — call again with offset={off + lim}]")
return (f"[{key} — {desc} — lines {off + 1}–{off + len(chunk)} of {len(lines)}]\n\n"
+ "\n".join(chunk) + more)
def t_drift(_args):
"""Full drift-check output. Reports its own non-verification rather than a clean bill."""
out = wd.sh([sys.executable, wd.DRIFT], timeout=30)
if out is None:
return ("UNESTABLISHED: governance-drift-check.py did not run. This is not a clean "
"result — the absence of findings from an instrument that failed to run "
"carries no information.")
return out
def t_repo(args):
"""Recent commits for one enumerated repo. Repo name from a fixed list, never a path."""
name = (args.get("repo") or "").strip()
if name not in REPOS:
return f"ERROR: unknown repo %r. Allowed: %s" % (name, ", ".join(REPOS))
path = os.path.join(HOME, "_Dev", name)
if not os.path.isdir(os.path.join(path, ".git")):
return f"NOT A REPO: {name} has no .git at {path}."
n = max(1, min(int(args.get("count") or 15), 100))
log = wd.sh(["git", "-C", path, "log", f"-{n}", "--format=%h %ad %s", "--date=short"])
status = wd.sh(["git", "-C", path, "status", "-sb"])
if log is None:
return f"UNREADABLE: git log failed in {name}."
return f"[{name}]\n\n{status}\n\nLAST {n} COMMITS\n{log}"
TOOLS = [
("governance_state", t_state,
"Current governance state, computed live: every open authorization item with its "
"[TAG], recent REVIEWED rulings, the CLAUDE.md drift count, and per-repo status. "
"Start here, then drill in with governance_item.",
{"type": "object", "properties": {}}),
("governance_item", t_item,
"Verbatim text of one authorization item or ruling by id (e.g. PENDING-81, "
"PENDING-S4, REVIEWED-80). Searches PENDING.md, PENDING-archive.md and REVIEWED.md. "
"Never summarised.",
{"type": "object", "properties": {"id": {"type": "string",
"description": "Item id exactly as it appears after '## ', e.g. 'PENDING-81'."}},
"required": ["id"]}),
("governance_read", t_read,
"Verbatim paged read of a governance document, chosen by key (not by path).",
{"type": "object", "properties": {
"file": {"type": "string", "enum": sorted(FILES),
"description": "Which document to read."},
"offset": {"type": "integer", "description": "0-based first line (default 0)."},
"limit": {"type": "integer", "description": "Lines to return, max 2000 (default 400)."}},
"required": ["file"]}),
("drift_report", t_drift,
"Full governance-drift-check output: claims in CLAUDE.md the substrate contradicts. "
"Detection only — correcting doctrine requires steward authorization.",
{"type": "object", "properties": {}}),
("repo_activity", t_repo,
"Branch, uncommitted-file status and recent commits for one of the active repos.",
{"type": "object", "properties": {
"repo": {"type": "string", "enum": REPOS, "description": "Repo name."},
"count": {"type": "integer", "description": "Commits to list, max 100 (default 15)."}},
"required": ["repo"]}),
]
IMPL = {n: f for n, f, _d, _s in TOOLS}
# ---- JSON-RPC over stdio ----------------------------------------------------
def handle(msg):
"""-> response dict, or None for notifications (which must never be answered)."""
mid, method, params = msg.get("id"), msg.get("method"), msg.get("params") or {}
def ok(result):
return {"jsonrpc": "2.0", "id": mid, "result": result}
if mid is None: # notification
return None
if method == "initialize":
want = params.get("protocolVersion")
return ok({"protocolVersion": want if want in PROTOCOLS else PROTOCOLS[0],
"capabilities": {"tools": {}},
"serverInfo": {"name": NAME, "version": VERSION},
"instructions": "Read-only view of the CapableMind governance substrate. "
"Nothing here writes. Call governance_state first."})
if method == "ping":
return ok({})
if method == "tools/list":
return ok({"tools": [{"name": n, "description": d, "inputSchema": s}
for n, _f, d, s in TOOLS]})
if method == "tools/call":
name = params.get("name")
if name not in IMPL:
return {"jsonrpc": "2.0", "id": mid,
"error": {"code": -32602, "message": f"unknown tool: {name}"}}
try:
text = IMPL[name](params.get("arguments") or {})
return ok({"content": [{"type": "text", "text": text}]})
except Exception as e: # a crash must not kill the session
return ok({"content": [{"type": "text",
"text": f"TOOL ERROR {type(e).__name__}: {e}"}],
"isError": True})
return {"jsonrpc": "2.0", "id": mid,
"error": {"code": -32601, "message": f"method not found: {method}"}}
def serve():
for line in sys.stdin:
line = line.strip()
if not line:
continue
try:
msg = json.loads(line)
except Exception as e:
print(json.dumps({"jsonrpc": "2.0", "id": None,
"error": {"code": -32700, "message": f"parse error: {e}"}}),
flush=True)
continue
resp = handle(msg)
if resp is not None:
print(json.dumps(resp), flush=True)
# ---- selftest ---------------------------------------------------------------
def write_calls(src):
"""-> list of filesystem-mutating calls in `src`, found by AST rather than text.
A grep for a forbidden-token list cannot audit the file that CONTAINS the list —
the first version of this check searched for `"w"`, `os.remove`, `shutil.` and
duly found all of them, in its own definition. That is the day's recurring shape:
an instrument whose domain includes itself. The AST sees calls, not characters."""
import ast
MUTATORS = {"remove", "unlink", "rename", "replace", "rmdir", "mkdir", "makedirs",
"chmod", "truncate", "write", "writelines", "write_text", "write_bytes"}
out = []
for n in ast.walk(ast.parse(src)):
if not isinstance(n, ast.Call):
continue
f = n.func
if isinstance(f, ast.Name) and f.id == "open":
mode = next((a.value for a in n.args[1:2] if isinstance(a, ast.Constant)), None)
mode = next((k.value.value for k in n.keywords
if k.arg == "mode" and isinstance(k.value, ast.Constant)), mode)
if mode and any(c in str(mode) for c in "wax+"):
out.append(f"open(mode={mode!r}) at line {n.lineno}")
elif isinstance(f, ast.Attribute) and f.attr in MUTATORS:
out.append(f"{f.attr}() at line {n.lineno}")
return out
def git_subcommands(src):
"""-> set of git subcommands invoked in `src`, read from AST argv literals.
The third self-inclusion failure of 2026-07-28, and the one that finally made the
pattern obvious: after moving the write-primitive audit to the AST, the git half of
the same check was left as `'"commit"' not in src` — and the source it reads now
contains `"commit"` and `"push"` as the literals of the check itself. A text search
for forbidden words can never clear a file that must name those words. Read argv
lists, not characters: `["git", "-C", path, "log", …]` -> {"log"}."""
import ast
out = set()
for n in ast.walk(ast.parse(src)):
if isinstance(n, ast.List) and n.elts:
first = n.elts[0]
if isinstance(first, ast.Constant) and first.value == "git":
for e in n.elts[1:]:
if not (isinstance(e, ast.Constant) and isinstance(e.value, str)):
continue # a variable (path, count) — skip
if e.value.startswith("-"):
continue # a flag, not the subcommand
out.add(e.value)
break
return out
def selftest():
ok = True
def chk(name, cond):
nonlocal ok
ok = ok and bool(cond)
print(f" [{'ok ' if cond else 'FAIL'}] {name}")
print("protocol:")
init = handle({"jsonrpc": "2.0", "id": 1, "method": "initialize",
"params": {"protocolVersion": "2024-11-05"}})
chk("initialize echoes a known client protocol",
init["result"]["protocolVersion"] == "2024-11-05")
chk("initialize falls back for an unknown protocol",
handle({"jsonrpc": "2.0", "id": 1, "method": "initialize",
"params": {"protocolVersion": "1999-01-01"}})["result"]["protocolVersion"]
== PROTOCOLS[0])
chk("notifications get no response",
handle({"jsonrpc": "2.0", "method": "notifications/initialized"}) is None)
chk("tools/list returns all tools",
len(handle({"jsonrpc": "2.0", "id": 2, "method": "tools/list"})["result"]["tools"])
== len(TOOLS))
chk("unknown method -> -32601",
handle({"jsonrpc": "2.0", "id": 3, "method": "nope"})["error"]["code"] == -32601)
chk("unknown tool -> -32602",
handle({"jsonrpc": "2.0", "id": 4, "method": "tools/call",
"params": {"name": "rm_rf"}})["error"]["code"] == -32602)
print("\ndomain is an enum, and the refusal is detectable:")
chk("governance_read refuses an unlisted key",
t_read({"file": "secrets"}).startswith("ERROR: unknown file key"))
chk("governance_read refuses a path traversal attempt (no path is accepted at all)",
t_read({"file": "../../.ssh/id_rsa"}).startswith("ERROR: unknown file key"))
chk("governance_read ACCEPTS a listed key [positive control for the refusal above]",
t_read({"file": "pending"}).startswith("[pending —"))
chk("repo_activity refuses an unlisted repo",
t_repo({"repo": "/etc"}).startswith("ERROR: unknown repo"))
chk("repo_activity ACCEPTS a listed repo [positive control]",
t_repo({"repo": REPOS[0], "count": 3}).startswith(f"[{REPOS[0]}]"))
print("\nitem lookup — presence, absence, and the 07-28 blind-spot family:")
chk("finds a numeric item", t_item({"id": "PENDING-81"}).startswith("[PENDING-81 — verbatim"))
chk("finds an S-series item [the family a regex-on-digits missed]",
t_item({"id": "PENDING-S4"}).startswith("[PENDING-S4 — verbatim"))
chk("finds a ruling in REVIEWED.md",
t_item({"id": "REVIEWED-80"}).startswith("[REVIEWED-80 — verbatim"))
chk("finds an item that lives only in the archive",
t_item({"id": "PENDING-72"}).startswith("[PENDING-72 — verbatim"))
chk("absent id -> NOT FOUND, not a silent empty",
t_item({"id": "PENDING-99999"}).startswith("NOT FOUND"))
chk("missing id -> explicit error", t_item({}).startswith("ERROR"))
chk("a shorter id does not match a longer one (PENDING-8 ≠ PENDING-81)",
t_item({"id": "PENDING-8"}).startswith("NOT FOUND"))
body = t_item({"id": "PENDING-81"})
# The body carries exactly ONE '## ' header — its own. The first version of this
# check asserted ZERO and failed against correct code: the returned text is
# prefix + the item INCLUDING its header. A self-test written before reading real
# output tests the author's model of the output (07-28T09:35, same shape).
chk("item body contains exactly its own header, no neighbour's",
len([l for l in body.split("\n") if l.startswith("## ")]) == 1)
chk("item body ends before the next item begins",
"PENDING-82" not in body and "PENDING-80 —" not in body.split("\n", 3)[2])
print("\nno second definition of 'open item':")
state = t_state({})
n_digest = len(wd.sec_pending())
chk(f"governance_state item count == wake-digest sec_pending() ({n_digest})",
f"OPEN AUTHORIZATION ITEMS ({n_digest})" in state)
chk("state names its own degradation when something cannot be computed",
"DEGRADED" in state or not wd.warn)
print("\nlive substrate:")
chk("PENDING.md readable", read(FILES["pending"][0]) is not None)
chk("REVIEWED.md readable", read(FILES["reviewed"][0]) is not None)
d = t_drift({})
chk("drift_report runs and does not fake a clean result",
d and not d.startswith("UNESTABLISHED"))
print("\nread-only guarantee (structural, via AST):")
src = open(__file__, encoding="utf-8").read()
chk("no filesystem-mutating call in this file",
write_calls(src) == [])
chk("the checker DOES flag writes when present [positive control — a text search "
"here would match its own token list, which is how the first version of this "
"check failed]",
len(write_calls("open('f','w')\nimport os\nos.remove('g')\np.write_text('h')")) == 3)
subs = git_subcommands(src)
chk(f"git is invoked read-only — subcommands present: {sorted(subs) or 'none'}",
subs and subs <= {"log", "status", "show", "rev-parse", "ls-files", "diff"})
chk("the checker DOES flag a mutating subcommand [positive control]",
git_subcommands('subprocess.run(["git", "-C", p, "push", "origin", "main"])')
== {"push"})
print("\nSELFTEST", "PASS" if ok else "FAIL")
return 0 if ok else 2
if __name__ == "__main__":
if "--selftest" in sys.argv:
sys.exit(selftest())
try:
serve()
except (BrokenPipeError, KeyboardInterrupt):
pass
+40 -9
View File
@@ -47,16 +47,39 @@ def read(p):
# ---------- extractors (pure functions of text, so --selftest can exercise them) ----------
def item_spans(text):
"""-> [(header, start, end)] for every item; 1-based start, end exclusive.
THE single definition of "an item" for every consumer. Two lessons are welded in:
- **Any `## ` header is an item.** A family-specific regex (`^## PENDING-<digits>`)
hid twenty items on 2026-07-28, ten of them open. Never match on family.
- **Fenced blocks are not the document's structure.** Governance drafts are
written as plain fenced markdown carrying their own `## REVIEWED-N` headers
(the steward's copy-paste-clean practice), so a fenced header would otherwise
register as a phantom item AND truncate the real item containing it. Zero such
headers exist in the substrate today; the trigger is a drafting habit already
in use, so this is a defect waiting on the next draft rather than a hypothetical.
"""
lines = text.split("\n")
heads, fence = [], False
for i, l in enumerate(lines):
s = l.lstrip()
if s.startswith("```") or s.startswith("~~~"):
fence = not fence
continue
if not fence and l.startswith("## "):
heads.append((l[3:].strip(), i + 1))
return [(h, s, heads[k + 1][1] if k + 1 < len(heads) else len(lines) + 1)
for k, (h, s) in enumerate(heads)]
def open_items(text):
"""-> [(header, line_no)] for every '## ' item lacking closure evidence.
Closure evidence = a REVIEWED-N (resolved by the caller) or CLOSED/COMPLETED
in the header. Any '## ' line is an item — assuming one naming family missed
twenty items on 2026-07-28."""
out = []
for i, l in enumerate(text.split("\n"), 1):
if l.startswith("## ") and "CLOSED" not in l and not l.startswith("## COMPLETED"):
out.append((l[3:].strip(), i))
return out
"""-> [(header, line_no)] for every item lacking closure evidence. Closure
evidence = a REVIEWED-N (resolved by the caller) or CLOSED/COMPLETED in the
header."""
return [(h, s) for h, s, _e in item_spans(text)
if "CLOSED" not in h and not h.startswith("COMPLETED")]
def tag_of(text, header):
@@ -290,6 +313,14 @@ def selftest():
chk("open_items excludes CLOSED / COMPLETED",
open_items("## PENDING-1 — x (CLOSED)\n## COMPLETED — y") == [])
chk("open_items returns empty on empty input", open_items("") == [])
FENCED = "## PENDING-9 — real\nbody\n```markdown\n## REVIEWED-9 — a draft\n```\ntail"
chk("open_items ignores a header inside a fenced block [drafting-habit trigger]",
[h for h, _ in open_items(FENCED)] == ["PENDING-9 — real"])
chk("open_items DOES find that same header unfenced [positive control for the line above]",
[h for h, _ in open_items(FENCED.replace("```markdown\n", "").replace("```\n", ""))]
== ["PENDING-9 — real", "REVIEWED-9 — a draft"])
chk("item_spans runs a fenced item to the tail, not to the fenced header",
item_spans(FENCED)[0][2] == 7)
chk("tag_of reads a tag",
tag_of("## PENDING-9 — t\n**Date:** d\n**Tag:** [ESCALATE]\n", "PENDING-9 — t") == "[ESCALATE]")
chk("tag_of returns '' when absent", tag_of("## PENDING-9 — t\n", "PENDING-9 — t") == "")