diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 37747fa..9ae9a24 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -15,7 +15,7 @@ We welcome contributions in many forms:
 ## Getting Started
 
 1. **Read the AI Manifest:** Start with `0-AI-MANIFEST.a2ml` (if present) to understand the repository structure.
-2. **Environment:** Use `nix develop` or `direnv allow` to set up your tools.
+2. **Environment:** Use `guix shell -D -f guix.scm` (or `direnv allow`) to set up your tools. Guix is the canonical packager per [standards#101](https://github.com/hyperpolymath/standards/issues/101); the prior `nix develop` fallback was retired.
 3. **Task Runner:** Use `just` to see available commands (`just --list`).
 
 ## Development Workflow
diff --git a/TESTING-AUDIT.md b/TESTING-AUDIT.md
index 24751ec..54c0966 100644
--- a/TESTING-AUDIT.md
+++ b/TESTING-AUDIT.md
@@ -98,7 +98,7 @@ baseline, add a CI job that fails if p95 regresses > 50%.
 | **Functionality** | strong | 39 Elixir + 38 Rust test files, ~8,659 Elixir LOC, full pipeline E2E |
 | **Versability** | strong | SemVer in `CHANGELOG.adoc` + `mix.exs`, detailed per-version changelogs |
 | **Maintainability** | strong | Modular Rust workspace, TOPOLOGY.md, DESIGN-NARRATIVE.md, clean module boundaries |
-| **Reproducibility** | strong | `flake.nix` + `guix.scm`, `Cargo.lock` + `mix.lock` committed |
+| **Reproducibility** | strong | `guix.scm` (canonical per standards#101 — `flake.nix` retired), `Cargo.lock` + `mix.lock` committed |
 | **Portability** | strong | Cross-platform CI matrix (Linux x86_64 / ARM64, macOS x86_64 / ARM64, Windows), Containerfile, podman |
 | **Dependability** | weak | OTP supervision + concurrency tests but no chaos engineering, no fault-injection |
 | **Performance** | weak | No published metrics, no latency / throughput benchmarks gated, no capacity planning |
diff --git a/flake.lock b/flake.lock
deleted file mode 100644
index 032fb8b..0000000
--- a/flake.lock
+++ /dev/null
@@ -1,61 +0,0 @@
-{
-  "nodes": {
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1751274312,
-        "narHash": "sha256-/bVBlRpECLVzjV19t5KMdMFWSwKLtb5RyXdjz3LJT+g=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "50ab793786d9de88ee30ec4e4c24fb4236fc2674",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-24.11",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "root": {
-      "inputs": {
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
-      }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}
diff --git a/flake.nix b/flake.nix
deleted file mode 100644
index 845d0ab..0000000
--- a/flake.nix
+++ /dev/null
@@ -1,52 +0,0 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath)
-#
-# Nix flake development environment for hypatia.
-# Usage: nix develop
-{
-  description = "Hypatia — neurosymbolic CI/CD intelligence platform";
-
-  # SECURITY: inputs pinned to a release branch rather than `unstable`
-  # for marginal supply-chain hardening. A generated `flake.lock` is
-  # still required for full content-hash pinning — run `nix flake lock`
-  # to produce one. The host where this commit was authored does not
-  # have `nix` on PATH, so the lockfile is intentionally absent from
-  # this commit; first developer with nix should generate and commit it.
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
-    flake-utils.url = "github:numtide/flake-utils";
-  };
-
-  outputs = { self, nixpkgs, flake-utils }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let pkgs = nixpkgs.legacyPackages.${system};
-      in {
-        devShells.default = pkgs.mkShell {
-          buildInputs = with pkgs; [
-            # Elixir/Erlang — BEAM-based rule engine
-            elixir
-            erlang
-
-            # Rust — CLI scanner and core analysis
-            rustc
-            cargo
-            clippy
-            rustfmt
-
-            # Idris2 — formal verification ABI
-            idris2
-
-            # Zig — FFI implementation
-            zig
-
-            # System dependencies
-            pkg-config
-            openssl
-          ];
-
-          shellHook = ''
-            echo "hypatia dev shell — elixir + cargo + idris2 + zig"
-          '';
-        };
-      });
-}