Cambium

Cambium is a governance standard and a reference toolset for knowledge repositories maintained with LLM agents, and it governs the work rather than the corpus. It has three layers. A normative kernel of numbered domains holds rules as prose plus machine contracts, and a per-repository profile may fill or tighten an extension point but never disable a kernel rule. Adoption is one explicit transaction that resolves an upstream reference to a full commit SHA as the sole Standards identity and rolls the previous control plane back if any step fails. Runtime state belongs to the adopter, where Coverage, Required Queue and Progress must agree without being interchangeable. Underneath, deterministic tools check, write and compile: every writer is a dry run until --apply, shared-state writes are integrator-only, and receipts are append-only JSONL where an uncertain append keeps its lock. It also names what does not ship — no scheduler, no authenticated identity, no protected whole-workspace execution — on the principle that a host must not claim evidence for a capability it cannot prove.

Who built itOf the repository’s 400 commits, 379 are attributed to his account, under three different names and three different addresses; fifteen commits are attributed to the claude account and three to codex, two to another person, and one carries an address wrapped in typographic quotes, so GitHub links it to no account at all. Ninety-five commits carry a co-author trailer, 67 naming Claude Opus 5 and 28 naming Claude Fable 5.

1. 01

   A standard carried in from another project, and not a single release

   The oldest commit in the repository is dated 2026-07-31 and its message is itself a provenance note: Baseline: Knowledge Base Standards v2.3 verbatim snapshot from Agent Systems Atlas. The repository was created four days later, on 2026-08-04, so Cambium does not begin with an empty directory — it begins with a standards document imported whole from an earlier project, and one of its two worked examples is still named after it. From there it moved quickly: 400 commits in six weeks, 13 in July, 309 in August and 78 in the first eleven days of September, ending with the merge of pull request 224. What it never produced in that time is a release or a tag; both counts are zero. Version identity is carried elsewhere. The adoption transaction resolves an upstream reference to its full Git commit SHA and records that SHA as the sole Standards identity, adopt_standards.py moves a task that is already running onto an approved revision without rewriting its lifecycle history, and the kernel fixes module numbers as stable identities that are not reused after a module moves or retires. The thirty issues and pull requests read here run from 195 to 224, and the numbering is the record of the loop: every odd number is an issue, every even number the pull request that closes it. All thirty are closed, and around them sit 478 stars, 31 forks, 12 watchers, four contributors and four open issues.

2. 02

   Which layer each party is allowed to write

   Effective governance is a sum: the kernel, plus exactly one selected profile, plus adopter-owned runtime state — and each term carries a different right. The kernel is normative: a profile may tighten an extension point but never disable a kernel rule, and tools execute declared rules without making the final semantic judgement. The adopter owns the runtime namespace, and the README states the prohibition flatly: do not edit canonical state by hand, use the owning writer, so that revisions, hashes, receipts and recovery evidence move together. Shared-state writes are integrator-only and require current revisions or hashes wherever a tool asks for them, and every writer is a dry run unless --apply is present. Adoption stays off the agent surface as an explicit command-line maintenance transaction whose external upstream repository input is never exposed as an unrestricted MCP argument; it binds the selected profile with the resulting contracts and evidence, resolves the upstream reference to a full commit SHA, and never restamps or rewrites the adopter’s own copy of the upstream material. Writing rights split by kind: slot meaning belongs to the kernel and its domain contracts, while TOML encoding and file layout belong to the tools. The same discipline reaches the draft: an unanswered field stays unanswered, because omission is not agreement to disable an option, and mechanical validity, user confirmation and adoption stay three separate things.

3. 03

   The shape of a change: one issue, one pull request, and the test counts

   Cambium reviews its own governance in a fixed form. Every pull request quoted here opens with a problem statement before anything else; the section headings in the sample are Problem, Scope, Required behaviour, Evidence and Validation, the changes are grouped by the machine owner they touch, and the boundaries that were preserved are named explicitly. The closing argument is usually a table: make check, then fast 898 of 898, integration 231 of 231, end-to-end 4 of 4, and a focused count that varies with the change — 64 focused lifecycle tests on one item, 74 focused kernel and tool tests on another, 39 focused tests on a third. Only two of the thirty items carry comments, and both comments are the maintainer diagnosing performance in public, with run identifiers, fixed source commits and tables of measured seconds. The same loop shows up in the commits: 95 of the 400 carry a co-author trailer, 67 of them naming Claude Opus 5 and 28 naming Claude Fable 5, while fifteen commits are attributed to the claude account and three to codex. Review is not prose alone here: issue ownership is a script under .github/scripts/, and the contributing guide is described as covering issue ownership, defect promotion and the pull-request contract.

4. 04

   What has to exist before work is allowed to close

   Evidence is the part of the model with the hardest edges. Receipts are JSONL and append-only, and an uncertain append keeps the lock rather than guessing whether the receipt landed; a surviving writer lock is recovery evidence that must not be deleted until the writer, state files, receipts, pending deltas and archive moves are reconciled. Exit code 2 is a hold, not success and not an ordinary failure, and reports and generated projections are views, never canonical input. The mechanism is named: one append-only evidence-invalidation-v1 producer, with exact target bindings, a dry run, idempotent event identity, and confirmed publication through both the command line and MCP. It exists because of a specific failure: a reviewer can record a structurally valid but incorrect judgement, and the lifecycle had no controlled way to withdraw that claim without changing source content or discarding history, so a checklist item marked not applicable was accepted and reused downstream while its frozen audit plan still listed required dependencies. The correction draws an authority line instead of adding authentication: a declaration may be withdrawn by its own author, by the existing semantic authority, or by an explicit user decision, and the integrator does not acquire judgement authority. These are operator and host attestations, not an authentication system.

5. 05

   Adjudicating between the stale record and the current one

   The sharpest defect class here is not a crash but a disagreement about which record is current. One report describes the ordinary case: a page changes inside an open batch, the producer creates a successor audit receipt, and the runtime currentness owner marks the predecessor stale. Stable validation of the consuming review then treated every matching historical receipt as current because no live currentness set had been supplied, and the persisted consumer was rejected for having multiple current attempts even though it cited the sole current successor. The owner’s own summary of the defect is the clearest statement of the rule — stale history remains valid history, and it must not block the current batch. The correction splits the two checks: stable validation reads exactly the immutable references the consumer recorded, and live validation independently checks that they equal the currentness projection. A later pair of items closes the same seam further along: receipt stage selection must survive batch close and terminal consumption, so a legitimate revision whose pre-merge selection picked the new evidence is not re-read at close time as two competing current candidates. That fix also rejects the cheap version of itself: narrowing the scan to the selected producers would have dropped earlier reconciliation history and the first-round body needed to validate a second-round review.

6. 06

   Budgeting the governor, and retiring what it grew out of

   A governance toolchain is itself governed, and here by a stopwatch. The required chain has a target of about 300 seconds and a hard limit of 360 seconds, and one fixed sample of the end-to-end scenario took 911 seconds, which the issue calls non-compliance even though the run passed inside a fifteen-minute job timeout. The measurement was then made explicit: two runs on pinned setups, once each on Python 3.10.21 and 3.14.7, reported 463.52 and 485.36 seconds, 454.02 and 476.94 for the existing end-to-end module, and 103.52 and 125.36 seconds left past the 360-second limit. Overrunning the limit must fail acceptance without truncating the measurement, so execution got an independent 1,800-second safety deadline. One gap is recorded rather than explained away: the same scenario was slower on 3.14 in one run and slower on 3.10 in another of an identical tree, and the logs cannot attribute the reversal to the interpreter. The proposed shortcuts were refused too: the issue states this is not a request to raise timeouts, drop Python 3.14, or mock the full lifecycle. What followed was a sequence of retirements: a superseded alias removed rather than kept, an empty receipt finaliser module deleted, a duplicated list-shape algorithm dropped, and a group of unsafe reuse — a checked-view cache, runner decorators, a public API declaration and cache-only assertions — retired together.