pi-canon

Canonical project memory for the Pi coding agent. Every asset has at most one governing article, at an address computed from the asset's own path: src/core/config.ts is governed by articles/src/core/config.md. Beneath the articles sits an append-only journal, one file per event. When a tool call touches a governed asset, that article's one dense line arrives in the session unasked, so the agent does not have to know there was something to look up. Detecting the path in a tool call is best effort; resolving it to an article is not.

An illustrative store: 33 articles, 20 journal entries, 40 files. Discs are articles, rings are journal entries hanging under the article each was distilled into, and a square tethered beneath a disc is the asset that article was named for. Six of the articles match no asset and hang untethered, because free knowledge is not a special case here. Selecting a node opens what it holds, what it points at, and what points at it.

Install

pi install npm:pi-canon

Or clone this repo into ~/.pi/agent/extensions/. Node 22.18 or later, Pi 0.83 or later on the 0.x line. Nothing to configure: the store is created on first write at <project>/.canon. The package imports node:fs and node:path and nothing else, makes no network calls, runs no git, and loads under plain node with no build step.

The first article

A session is not greeted: through 0.2.0 every session opened with an orientation line, and a 2x2 experiment with an inert implementation priced that line at more first-pass correctness than the whole tool schema, so 0.2.1 deleted it. The tool description carries the doctrine instead. The first article takes one tool call:

{ "action": "write",
  "path": "src/core/config",
  "capsule": "Loads layered config; env beats file; secrets never land here.",
  "body": "Resolution order is defaults, then config.toml, then environment. ..." }

Wrote src/core/config.

The store, after that write and a little later work:

.canon/
  articles/
    src/core/config.md        governs the src/core/config address
    lake/prices.md            articles are not limited to code
  journal/
    2026-08-11-vendor-cap.md  one file per entry, never rewritten by the tool

The article itself:

---
capsule: Loads layered config; env beats file; secrets never land here.
updated: 2026-08-11
---
Resolution order is defaults, then config.toml, then environment. ...

That is the whole storage format. capsule is the one dense line surfacing sends, collapsed to a single line on write whatever the agent sent. updated is the date of the last write, which is not the date the content last changed, and nothing compares it against the asset. Those two keys are the only ones pi-canon owns. Every other key in the block, Obsidian properties included, is carried through writes verbatim, and owned values are quoted only where plain YAML would misread them, so the tree stays editable by hand.

The result is plain Markdown and a valid Obsidian vault. Commit it with your repo: git is the history, diff, blame, and time machine, and pi-canon never runs git itself. Journal entries are ordinary files too. The tool only appends them; read them with normal file tools.

The failure this is shaped for

An agent formats a column of raw integer cents for a human reader, 2,255.65 where the file carried 225565. The tests pass. In another repository, one nobody opened during that session, a finance parser reads that file and treats any line with a comma in it as corrupt, so it drops the line and reads on. No exception, no failing build, and a number missing from a downstream total until someone reconciles by hand.

Retrieval cannot prevent this, because a search only runs when something thinks to run it. Formatting a number for readability is not a moment that raises a question. There was nothing to suspect, so there was nothing to search for.

The expensive failures in project work are not the ones where an agent looked something up and got a bad answer. They are the ones where nobody knew there was a question to ask.

That scenario is not a war story. It is one of the five chains in the benchmark below, written because it is the shape of failure this package exists to prevent. No arm of that benchmark is search-driven, so this is the motivation for the design rather than a measured comparison against retrieval.

Where this comes from

The shape underneath pi-canon is the LLM wiki: a folder of Markdown articles an agent writes and rewrites, linked to each other, with no schema declared in advance. Andrej Karpathy introduced and popularized the pattern in llm-wiki.md, positioned against re-retrieving raw chunks at query time. Most of what it gets right is kept here unchanged. Plain files, so anything can read them and a person can fix one in an editor. No database and no index to rebuild. Committed with the repository, so git supplies history, diff, and blame. And no schema up front, so knowledge takes the shape the project actually has.

That freedom is also where these stores fail, in two specific directions rather than vaguely.

Scatter. Nothing marks any article as the article about a topic, so an agent that cannot find the existing one writes another. Now there is a note on the vendor feed, a second on feed pagination, and a third on the sync job, all describing the same constraint from three angles, none of them wrong. Retrieval finds all three, the agent reads whichever ranks highest, and when they disagree nothing decides between them.

Log drift. A store an agent writes to during work fills with events, because work is made of events: what was tried, what failed, what got fixed. Current truth ends up under a running log of how it came to be true, and the page that should say what the rule is says what happened on the fourteenth instead.

Neither is a storage failure. In both, the knowledge is present, written down, sitting right there in the folder. Scatter is an addressing failure: precedence is undefined across copies because nothing names one of them canonical. Log drift is a mutability failure: event history and current reference knowledge share one page, and a later rewrite can edit either one out from under the other.

pi-canon is an increment on the pattern rather than a replacement for it, and it adds three things.

A journal, append-only, one file per event. Agents log whether you want them to or not, and that impulse has to land somewhere that is not the reference page. The instruction on the way in is to record the source as it arrived, names and exact numbers included, because articles distill and only the journal keeps the original.

A spine, the addressing convention. An article's address is computed from the asset instead of searched for, and nothing has to be configured for that mapping to hold, which makes the spine a convention rather than a mode. It is also why nothing in the RECALL path searches: when a touch already decided the address, there is nothing to find. The search action exists for the opposite direction, the agent that wants to ask, and it never runs unasked.

Surfacing, push rather than pull. When a tool call is detected touching a governed asset, that article's capsule is staged for the session, at most once per article, so nobody has to think to ask. Detection of a path inside a tool call is best effort. Resolution, once a path is in hand, is not.

The evaluation below does not test that lineage argument: no evaluated arm is a search-driven LLM wiki, so nothing here shows pi-canon beats a disciplined one.

Addressing

The address is the asset path with its file extension dropped, and the drop happens once, at the boundary. A name has to precede the dot, so .env stays .env. Only a dot after the last slash counts, so docs/v1.2/notes.md normalizes to docs/v1.2/notes. And src/core/config.test.ts lands at src/core/config.test, beside config rather than on top of it. Dot segments clamp at the root, and containment is checked a second time inside write, so no address escapes articles/.

Resolution tries the exact address, then walks up one path segment at a time to the nearest existing article, and returns nothing if it reaches the top without a hit. There is no ranking, no scoring, and no similarity: given a path, the governing article is a function of what exists in the tree. So not every file needs an article: one article at src/feed answers for everything beneath it that has no closer article. Creating an article is the uncommon act; the common one is updating the article that already governs.

A rename is a file move you make yourself. pi-canon does not watch the filesystem and has no rename action. Move the article to the address the new path derives. Lint checks the wikilinks inside whatever article is written next, so a link left pointing at the old address is named the next time that article is written, not at the moment of the move.

An article matching no asset is ordinary free knowledge. The spine guarantees an address for the assets a project already has; it does not confine the store to them. The tradeoff is worth stating in the same breath: surfacing is asset-scoped, so an off-spine article is reached by a link or an explicit read rather than pushed on a touch, or by relevance when a retriever is configured.

Such an article may say so, with scope: rule on the write. Nothing filters on it, because a declaration the agent forgot must never cost it the only mechanism that can reach it. What it buys is that the two populations stop being one number: an article off the asset path is either a cross-cutting rule filed exactly where the doctrine asked for it, or an article whose asset was deleted under it, and those want opposite things. scope: asset takes the declaration back.

The tool

One tool, pi_canon, five actions: read, write, journal, map, and search.

| action | parameters | does | |---|---|---| | read | path | Returns the governing article: title, capsule, updated, body, and a one-line journal index. A miss returns a sentence naming the address and inviting a write after the task. When an ancestor answers, the title reads <ancestor> governs <address>, so the altitude is visible. | | write | path, capsule, body, scope | Creates or updates the article, then returns Wrote <address>. and any advisory lint. Never refuses. An empty string means untouched, not erase. | | journal | body, subject, slug | Appends a dated entry as its own file, <date>-<slug>[-n].md. pi_canon can never rewrite one. An empty body gets a sentence back asking what happened. | | map | path (optional prefix) | One line per article as address: capsule, or a sentence when the store or the filter is empty. Output is unbounded. | | search | query | Ranks articles and journal entries against the words in one pass, ten results, each carrying what scopes it: an article its address and capsule, a journal entry its instant and subjects. Says how many matches the cap dropped. The one action that reaches the journal's content. |

subject is an array of addresses. A subject passed as a bare string is ignored and the entry lands with none at all.

Entries logged with subject addresses come back as a one-line index of filenames, newest three, when those articles are read: history on offer, never loaded by default. The index carries filenames only and never entry content, and matching is exact, so an entry filed at src/core/config does not appear when src/core is read. The journal always lives in the project store.

Lint on a write is advisory strings appended to the response, never a refusal, because a blocked write teaches an agent to stop writing while a warning teaches it what to do next. It warns past 8,000 characters of body and suggests going hierarchical past 20,000. It names a missing capsule, one over 1,000 characters, or one written as a change log. An address carrying a log, journal, session, standup or meeting segment, or an ISO date, draws a redirect to the journal. Dead wikilinks are named one line each.

One lint line is different in kind. When a write supplies a body and an article was already there, the new body is compared against the prior one, and a line that carried constraint language and disappeared is quoted back at the write that removed it. The vocabulary is fixed: must, never, always, require in its requires and required forms, do not, and don't. At most two lines are named per write, each cut to its first 160 characters, with the note that if the constraint still holds it should stay, and if it genuinely changed, the change belongs in the journal. The quote is a prefix rather than a summary. It is an advisory: the write already landed, and nothing can make an agent put the line back.

Surfacing

A tool call stages the governing article for whatever it touched and sends nothing. Each turn end flushes everything staged as a single message, because pi's steering queue drains one message per provider round trip and a message per tool call would buy every nudge its own model call. An article surfaces at most once per session, and nothing about that persists: a new session re-surfaces everything.

No character count decides any of this. A capsule is written to fit 1,000 characters, and that is a target handed to the agent at write time, not a gate at read time: an article whose governing asset a turn touched surfaces whole or does not surface. Earlier versions charged capsule text against a session allowance and degraded the overflow to bare pointers. That allowance was removed in 2.0. It was a constant guessing at a policy nobody had measured, and what it decided was how much an agent got to see. What stands in its place is measurement: every surfaced line records what it cost the window, so context taken can be read against relevance afterwards instead of a constant ruling on it in advance. The one remaining reason a line is not capsule text is an article that has no capsule, which surfaces as a pointer naming the address and telling the agent to read it.

Reading an article through pi_canon withdraws the line staged for it before the message goes out, so pull preempts push. Reading the asset file itself does not, because reading a file is not reading what is known about it, and the capsule may hold exactly the constraint the file does not contain. After the agent settles, articles touched but not updated draw one reminder naming them, once per batch, re-armed by the next touch.

Finding a path in a tool call is best effort. Only the input of a tool call is scanned. Results are never scanned, and neither is the model's prose. Inputs are scanned for whole short strings and path-shaped tokens that exist on disk or whose parent directory does, so a file about to be created still surfaces its governing ancestor, and a path with a space inside a longer string is missed. What that feeds, resolution from a path to a governing article, is deterministic. The two claims stay separate on purpose.

/pi-canon prints one status line: store root, the mount count when there is one, article count, journal entries, articles surfaced this session, and how many of those are still in context and what they occupy. It goes to the UI and sends the model nothing, so asking costs no context. PI_CANON_TRACE=<file> appends one JSON line per surfacing decision, and is inert when the variable is unset.

Options

Installed as a package, pi loads the default export and takes the defaults. To pass options, write your own extension file and let it call the named export:

// ~/.pi/agent/extensions/my-canon.js
import { registerPiCanon } from "pi-canon"

export default function (pi) {
  registerPiCanon(pi, { mounts: ["/data/lake"] })
}

Six keys, and any other throws at registration by name, because everything else is a constant on purpose.

• root places the store. Absolute is used as given, relative joins the project cwd. Default <project>/.canon.

• surface: false silences the per-turn flush and the settle reminder. The pi_canon tool and /pi-canon stay registered and working.

• resurface: false returns an article to surfacing at most once per session however long ago it left the window. The default is true: an article counts as seen only while it is still in the context the provider receives, so one folded or compacted away surfaces again the next time its asset is touched. A fresh touch is what brings it back, so nothing re-surfaces on its own.

• retrieval ranks the articles that govern no asset, the one category the address spine can never reach, against what the agent is doing. The default is "none", which ranks nothing and surfaces nothing unaddressed: the spine alone, exactly as 1.0. "lexical" is BM25 over the standard library, no dependency and no model. Anything that needs a model is supplied here as { name, score, index? }, so this package never carries one and never decides which you run. With a retriever configured the tool's filing rule changes with it, because the advice costs knowledge in either direction. On the default it says knowledge filed off the asset path never surfaces, which is true and is why you should not file it there. With a retriever it says the opposite: a constraint governing many assets and owning none belongs at its own address naming the rule, because the only parent unrelated packages share is the root and a root article surfaces on every touch of anything.

• standout is how far the best-ranked article must beat the best one that will not ride anyway, meaning the fourth, the one the three-per-message cap was already going to leave behind. A multiple, not a score: standout: 1.5 asks for the best to score half again what the first held-back rival scored. Default 1.4, an operating point priced by a 120-cell benchmark rather than picked: it matched the uncut channel's delivery to within that benchmark's own noise floor while cutting suggestions from 26 a session to 3, raised the rate at which the agent acted on one from 0.17 to 0.82, and never fired at all on a store with nothing relevant to say, 0 rankings of 139. Precision is the side to protect, though the measured argument is tokens rather than attention: the same benchmark found good suggestions opened at the same rate buried among twenty-seven as one of four, so what the cutoff saves is the context it declines to spend on lines that were never going to be read. The other side has a price too, and the same benchmark paid it: a cutoff set past what a decisive ranking reaches silences the channel, and at 2.0 it delivered nothing and gave back everything the channel had won. standout: 1 is no cutoff, the measurement setting for reading your own store's trace. Below 1 throws at registration, because it asks for the best article to be worse than its rival and is what a caller writes who is still thinking in scores.

  It is a ratio because a score is not the same quantity twice. lexical normalizes against a saturation ceiling computed from the query, so a score is a fraction of the best match POSSIBLE for that query rather than of the best match available in your store, and it falls as the agent says more. On a 380-article store the same article at the same relevance scored 0.68 against a short question and 0.16 with a hundred words of tool output around it. Across two benchmark runs it was worse than unstable, it inverted: keeping the answers on one corpus needed a cutoff below 0.11, and silencing the other needed one above 0.73. Dividing by another score from the same query cancels both.

  The comparison is against the top of the ranking, not a quantile of it, because an agent's turn is long and touches nearly everything: 377 of 378 articles in a benchmark session, so a tenth of the way down the list is deep in the mass that shares one common word, and the ratio to it describes your corpus rather than this query. Measured there, ordinary queries reached 2.64 to 3.28 and the query that actually had something to find reached 3.10, inside that range rather than above it. In the first few ranks the same sessions separated cleanly: every ranking carrying a decisive article beat its first held-back rival by 1.68 to 1.81, and every ranking that did not stayed between 1.00 and 1.28. Still measure on your own store: set PI_CANON_TRACE and read the ranked lines, which record what each query reached and whether it passed.

  A drained store does not turn the ratio into a free pass. Late in a long session, once most of what a small store had to say has been delivered, the still-eligible articles are a tail of near-zero scores, and a ratio over leftovers alone would ride junk on tiny numbers. So while the cutoff is active, the rival the best must beat is floored at the strongest already-delivered article this same query raised: what is left has to beat what the query would have re-raised if it could. A genuinely new topic clears that floor because the delivered articles score weakly on its query; leftovers do not. Replayed over a real 33-article store that the unfloored ratio had emptied entirely into the window, 33 articles down to a minimum ride score of 0.002, the floor cut the session to 15 rides with a floor of 0.075, and the strongest ride improved, because the store had not been spent on junk before the query that deserved it arrived.

The query is intent and never evidence: the user's own words out of the live context, newest first and bounded, keeping both ends of a message too long to carry whole because neither end is reliably the ask, plus this turn's tool calls by name and first argument. Tool results never reach it, and neither does the model's prose, and pi-canon's own nudges are excluded so an article cannot score highly for having been surfaced already. Relevance and transport are bounded separately: standout rules on whether the query gets an answer at all, and on top of it at most three ranked articles ride one message, best score first, with articles reached by address never counted against that, because an address is a certainty and a score is a guess. A ranked article is paid for by new intent rather than by another turn passing, so an unchanged question does not keep releasing three more until the residue runs out. The trace records the best score held back against the worst one sent. A retriever that throws costs the turn its ranking and nothing else.

• mounts lists directories outside the project that carry their own .canon beside their assets. mounts: ["/data/lake"] serves articles as lake:prices, addressable by that name or by any absolute path inside the mount. Two workspaces that mount the same directory read and write the same store, because the store lives with the assets it governs and sharing needs no protocol. A mount has no journal of its own: events are project history and every entry lands in the project store.

What the code holds, and what it asks for

An immutable journal, an addressing spine, and recall that arrives unasked could sound like a design that removed its dependency on model behavior. It did not. It moved that dependency to one side of a line and constrained the other side, and the line is short enough to state in full.

Held by the runtime:

• A journal entry is created with the exclusive-create flag, so pi_canon never rewrites or deletes one, and a name collision increments a suffix rather than losing an entry. The files stay ordinary Markdown, so any other tool can still rewrite or delete one: append-only is a property of the tool, not of the filesystem.
• Once a path is in hand it resolves to exactly one article, walking to the nearest ancestor that has one, or to nothing at all.
• An article surfaces whole, with no character count able to truncate it or hold it back.
• An article surfaces at most once while it is present in the context the provider receives. Presence is read from that projection rather than remembered, so folding or compaction returns the article to surfacing; a harness that reports no projection degrades to at most once per session.
• Reading an article through the tool withdraws its staged capsule before the message goes out.

Asked of the agent, and checked by nothing:

• Read the governing article before working on an asset, and update it after real changes. No write is gated on a prior read, and the settle reminder is a message rather than a gate.
• Record the source as it arrived, names and exact numbers included, because articles distill and only the journal keeps the original.
• File the entry under the right subject, and file a constraint at the asset it governs rather than the asset you happened to edit. Knowledge filed off the asset path never surfaces.
• Open the article when a capsule or a pointer says there is one. A line in the context is not a read.
• Decide whether a dropped constraint still holds. Then follow the rule, against a live prompt asking for something else.

Nothing in the package can compel an agent to keep a line it has decided to cut.

What the package does not do, stated so nothing above reads as more than it is:

• No search that runs unasked. search is an action the agent calls; touches resolve to articles by exact address or the ancestor walk, never by ranking, and no query ever fires on the agent's behalf.
• No embeddings and no model. retrieval: "lexical" builds a BM25 index over the articles that govern no asset, and nothing else is ranked ever; any other ranker is a function the caller supplies.
• No filesystem watching, and no staleness detection: updated is the date of the last write and is never compared against the asset.
• No delete and no rename. Removing or moving an article is a file operation you perform.
• Articles are last write wins, with no lock, no merge, and no warning that someone else changed the file. Only journal entries get the collision retry.
• No duplicate detection. One canonical address per asset is structural, not checked.
• Nothing writes, summarizes, or compacts on its own, and nothing filters what goes in: no secrets scanning and no redaction. Every line pi-canon wrote came from an explicit tool call.
• Nothing about surfacing persists between sessions. A new session re-surfaces everything.
• Presence is tested by looking for the article's capsule in the projection, so a capsule too short to be distinctive is never expired, and a digest that does not carry the capsule counts as absent.

Evidence

The population comes before the numbers: five author-built chains, development-exposed and reused by the confirmatory run, four eligible trap designs, each repeated five times, one worker model, under a protocol frozen with a hash manifest before that run.

The unit is a cell: a fresh worktree holding a small fictional repository, run through four sessions that share it. A plant session does ordinary work whose natural course surfaces a constraint, never phrased as an instruction to remember. A distractor session comes in between. A probe session then gets a task whose obvious solution violates that constraint in a way that compiles, runs, and fails a grader the agent never sees. A recall session answers an auditor afterwards, one judge call per fact.

Four arms run every cell. canon is stock Pi plus this package at 0.1.0, the build the study measured. canondoc is canon plus a static doctrine file beside it. agents.md is a self-maintained convention file preloaded with 99 lines of mature-project noise. bare loads no memory extension, and it is a stronger floor than the name suggests: prior-session transcripts land in its worktree before the recall session and its agent is on record reading them, so it is a no-extension floor at probe time and a transcript baseline at recall.

| arm | trap cells (of 20) | all checks (of 110) | plant-only recall (of 45) | median recall tokens | total chain cost | |---|---|---|---|---|---| | canon | 19 | 109 | 41 | 20,775 | $0.5454 | | agents.md | 18 | 107 | 42 | 64,568 | $0.6227 | | canondoc | 16 | 105 | 40 | 13,991 | $0.4639 | | bare | 8 | 85 | 40 | 61,006 | $0.5345 |

One square per eligible probe cell: four trap designs across, five repetitions within each, one row per arm. Every consumer-contract cell is a loss for bare. canon loses one cell in the whole grid, chain 04 repetition 1, which is the design that costs every arm at least one.

Read the unconditioned column beside the headline one. The trap metric is conditioned on the floor arm's cold failures, which is the strongest objection to it, so the unconditioned count scores all 110 intended checks whether or not a cold worker had already failed them, and the ordering survives. That count is check-level rather than an unconditioned version of the cell metric, and it was computed after the run rather than frozen with the protocol. Read the 18 before the 8: a self-maintained convention file, deliberately burdened with 99 lines of noise, finished one repeated cell behind the package, and quoting the gap against the floor without that number would be managing the reader rather than informing them.

Recall is a wash and has to be reported as one. Plant-only recall, 45 judged facts per arm: agents.md 42, canon 41, canondoc 40, bare 40. One fact flagged as paraphrase-sensitive before the freeze carries 9 of the 17 misses across arms, and striking it leaves canon level with bare. An ordering that moves when one judged item is removed is not an ordering.

Where the arms separate is the price of the answer. Median recall session tokens ran canondoc 13,991, canon 20,775, bare 61,006, agents.md 64,568, so canon answers at 0.34x bare's median. That does not make it the cheapest arm end to end. Total chain cost ran canondoc $0.4639, bare $0.5345, canon $0.5454, agents.md $0.6227, so canon is not the cheapest arm overall, and canondoc is lowest on both metered measures while passing three fewer trap cells. Every dollar figure is metered worker-session cost at that day's rates; the judge calls sit outside all of them, in equal number per arm. A package-level study offers no account of why.

The result that changed the roadmap is not in that run at all. A forensic pass over a development run classified 14 recall misses by where each first went wrong.

The 14 recall misses from a development run, each placed at the point it first went wrong: 8 never captured into any tier, 5 captured and then overwritten by a later rewrite, 1 judge error, and 0 lost at retrieval or surfacing.

That is development evidence over two arms of one run and it carries no confirmatory weight, but 13 of 14 is not a close call and it points somewhere specific. None of the misses was a fact sitting in the store that recall failed to reach, which is the failure a retrieval-shaped design would predict. A store that surfaces perfectly cannot surface what was never written down, so on this evidence the open problem is write-side fidelity rather than recall coverage: the hard moment is when an agent has just learned something, is mid-task, and has a live prompt in front of it asking for something else. The constraint guard is a first answer to the rewrite half of that, and an incomplete one.

What the run does not establish

• The five chains are development-exposed. The product changed in response to failures on these same chains, and the confirmatory run reuses them, so the freeze confirms disciplined execution rather than generalization to unseen tasks.
• The result is package-level. It attributes nothing to the journal, the spine, or surfacing separately. A later development probe tried to: a sham arm carrying this package's exact tool schema and orientation line with an inert implementation, so the surface is present and no memory work happens behind it. On one chain at 15 repetitions, first-pass correctness ran bare 12/15, canon 8/15, sham 7/15. canon and sham are indistinguishable (Fisher exact, p=1.0000) and neither separates from bare at that size (p=0.25 and p=0.13). Fifteen repetitions cannot establish equivalence, so read it as the absence of a signal rather than the presence of a null. What it does say is that any account of this package's costs has to start with the tool surface, because nothing behind the surface has yet been shown to contribute to them.
• No evaluated arm is a search-driven LLM wiki, so nothing here is a comparison against one.
• The agents.md arm is one construct, a self-maintained file under author-designed preload noise, with no clean-file or human-maintained counterpart run beside it.
• Eligibility is model-relative. A check counts as a trap only where a cold run of the worker failed it, so every number built on it moves when the worker does.
• One author wrote the package, the chains, the traps, and the graders.
• Five repetitions of one trap design are five looks at one design, so no uncertainty interval is attached to any pooled count.

More

• The paper, with the per-cell artifact trail: doi:10.5281/zenodo.21890647.
• The benchmark, drivers, frozen protocol, and the verifier that recomputes the paper's quantitative claims from the artifacts: canon-bench.
• Interactive versions of every figure and the full measurement story: shaneconner.com/projects/pi-canon.
• The narrative version: My agents' wiki was written faster than it was read.
• pi-fold, a separate optional package serving the working tier. pi-canon ships the two persistent tiers of the same four-tier stack: the journal is the episodic tier, the canon the semantic tier. The two compose, neither requires the other, and neither knows what the other has spent.

MIT. In a clone of this repo, node tests/verify.mjs runs the gate suite: every invariant prints by name and the run must end all N gates green, 142 of them at this release.