This repository has no description
wrapperModules.claude-code: add declarative wrapper module
- wrapperModules/claude-code: declarative options for skills, commands,
agents, mcpServers, hooks, permissions, settings, and claudeMd
- Assembles a plugin directory (--plugin-dir) and settings.json
(--settings) injected into every claude-code invocation
- claudeMd lines are fuzzy-merged into ~/.claude/CLAUDE.md using
Levenshtein distance (only adds, never removes user content)
- 5pkgs/levenshtein: small C tool for edit distance, threshold check,
and line-level file merge
- tools/claude: rewritten to consume the new wrapper module
author
lassulus
date
(Apr 8, 2026, 7:10 PM +0100)
commit
b763e91b
b763e91bdb53bf7fceac942a2a15e8d989811fdc
parent
e2dd087c
e2dd087cd11f96a4974bbd05360a8b2835018456
+507
-30
+1
flake.nix
+1
flake.nix
+157
5pkgs/levenshtein-merge/levenshtein.c
+157
5pkgs/levenshtein-merge/levenshtein.c
···
1
+
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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static int min3(int a, int b, int c) {
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if (a < b) return a < c ? a : c;
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return b < c ? b : c;
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}
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static int distance(const char *a, const char *b) {
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size_t la = strlen(a), lb = strlen(b);
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int *prev = calloc(lb + 1, sizeof(int));
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if (!prev) exit(1);
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for (size_t j = 0; j <= lb; j++) prev[j] = (int)j;
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for (size_t i = 1; i <= la; i++) {
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int corner = prev[0];
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prev[0] = (int)i;
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for (size_t j = 1; j <= lb; j++) {
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int val = min3(prev[j] + 1, prev[j-1] + 1,
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corner + (a[i-1] != b[j-1]));
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corner = prev[j];
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prev[j] = val;
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}
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}
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int res = prev[lb];
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free(prev);
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return res;
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}
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+
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/* Collapse whitespace and trim. Returns malloc'd string. */
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static char *normalize(const char *s) {
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while (*s == ' ' || *s == '\t') s++;
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size_t len = strlen(s);
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char *out = malloc(len + 1);
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if (!out) exit(1);
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size_t o = 0;
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int in_space = 0;
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for (size_t i = 0; i < len; i++) {
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if (s[i] == ' ' || s[i] == '\t') {
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if (!in_space && o > 0) out[o++] = ' ';
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in_space = 1;
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} else {
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out[o++] = s[i];
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in_space = 0;
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}
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}
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if (o > 0 && out[o-1] == ' ') o--;
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out[o] = '\0';
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return out;
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}
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static int fuzzy_match(const char *a, const char *b, double threshold) {
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int dist = distance(a, b);
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size_t la = strlen(a), lb = strlen(b);
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size_t m = la > lb ? la : lb;
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if (m == 0) return 1;
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return (double)dist / (double)m <= threshold;
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}
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/* Dynamic line array */
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struct lines { char **l; size_t n, cap; };
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static void lines_init(struct lines *v) {
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v->n = 0; v->cap = 64;
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v->l = malloc(v->cap * sizeof(char *));
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if (!v->l) exit(1);
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}
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static void lines_push(struct lines *v, char *s) {
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if (v->n == v->cap) {
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v->cap *= 2;
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v->l = realloc(v->l, v->cap * sizeof(char *));
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if (!v->l) exit(1);
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}
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v->l[v->n++] = s;
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}
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static void read_lines(const char *path, struct lines *v) {
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FILE *f = fopen(path, "r");
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if (!f) return;
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char *line = NULL;
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size_t cap = 0;
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ssize_t len;
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while ((len = getline(&line, &cap, f)) != -1) {
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if (len > 0 && line[len-1] == '\n') line[len-1] = '\0';
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lines_push(v, strdup(line));
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}
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free(line);
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fclose(f);
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}
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int main(int argc, char **argv) {
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if (argc == 3) {
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printf("%d\n", distance(argv[1], argv[2]));
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return 0;
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}
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if (argc == 5 && strcmp(argv[1], "-t") == 0) {
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double t = atof(argv[2]);
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return fuzzy_match(argv[3], argv[4], t) ? 0 : 1;
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}
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if (argc == 5 && strcmp(argv[1], "merge") == 0) {
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double threshold = atof(argv[4]);
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struct lines target, managed, known;
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lines_init(&target);
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lines_init(&managed);
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lines_init(&known);
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read_lines(argv[3], &target);
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read_lines(argv[2], &managed);
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/* Build normalized index of target lines */
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for (size_t i = 0; i < target.n; i++) {
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char *n = normalize(target.l[i]);
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if (n[0]) lines_push(&known, n);
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else free(n);
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}
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/* Find managed lines missing from target */
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struct lines missing;
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lines_init(&missing);
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for (size_t i = 0; i < managed.n; i++) {
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char *n = normalize(managed.l[i]);
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if (!n[0]) { free(n); continue; }
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int found = 0;
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for (size_t j = 0; j < known.n; j++) {
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if (fuzzy_match(n, known.l[j], threshold)) {
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found = 1;
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break;
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}
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}
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if (!found) {
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lines_push(&missing, managed.l[i]);
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lines_push(&known, n);
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} else {
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free(n);
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}
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}
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if (missing.n == 0) return 0;
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FILE *f = fopen(argv[3], "a");
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if (!f) { perror(argv[3]); return 1; }
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fprintf(f, "\n");
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for (size_t i = 0; i < missing.n; i++)
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fprintf(f, "%s\n", missing.l[i]);
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fclose(f);
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return 0;
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}
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fprintf(stderr,
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"usage: levenshtein-merge <a> <b>\n"
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" levenshtein-merge -t <threshold> <a> <b>\n"
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" levenshtein-merge merge <managed> <target> <threshold>\n");
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return 2;
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}
+25
5pkgs/levenshtein-merge/package.nix
+25
5pkgs/levenshtein-merge/package.nix
···
1
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{
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lib,
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stdenv,
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}:
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stdenv.mkDerivation {
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pname = "levenshtein-merge";
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version = "0.1.0";
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src = ./.;
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+
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buildPhase = ''
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$CC -O2 -o levenshtein-merge levenshtein.c
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'';
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+
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installPhase = ''
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install -Dm755 levenshtein-merge $out/bin/levenshtein-merge
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'';
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meta = {
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description = "Fuzzy line-level file merge using Levenshtein distance";
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license = lib.licenses.mit;
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mainProgram = "levenshtein-merge";
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platforms = lib.platforms.all;
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};
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}
+24
-30
tools/claude/flake-module.nix
+24
-30
tools/claude/flake-module.nix
···
3
3
perSystem =
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{ pkgs, system, ... }:
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let
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# Get paths to MCP servers
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gitMcpPath = "${self.packages.${system}.git-mcp}/bin/git-mcp";
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tmuxMcpPath = "${self.packages.${system}.tmux-mcp}/bin/tmux-mcp";
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claude = inputs.wrappers.lib.wrapModule {
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imports = [ self.wrapperModules.claude-code ];
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inherit pkgs;
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# Path to CLAUDE.md
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claudeMd = ./CLAUDE.md;
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claudeMd = ./CLAUDE.md;
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mcpServers = {
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git-mcp = {
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command = "${self.packages.${system}.git-mcp}/bin/git-mcp";
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};
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tmux-mcp = {
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command = "${self.packages.${system}.tmux-mcp}/bin/tmux-mcp";
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};
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};
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# Seed permission rules from the same set we trust in pi.
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permissions = {
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allow = [
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"Bash(nix build:*)"
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"Bash(nix eval:*)"
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"Bash(nix fmt:*)"
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];
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};
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};
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in
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{
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packages.claude = inputs.wrappers.lib.wrapPackage {
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pkgs = pkgs;
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package = (self.lib.halalify pkgs.claude-code);
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wrapper =
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{ exePath, ... }:
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''
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set -efu
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set -x
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# Configure MCP servers using Claude CLI
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if ${exePath} mcp add git-mcp "${gitMcpPath}" 2>/dev/null && \
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${exePath} mcp add tmux-mcp "${tmuxMcpPath}" 2>/dev/null; then
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echo "MCP servers configured successfully" >&2
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else
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echo "Warning: Could not configure MCP servers" >&2
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fi
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-
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# Set up CLAUDE.md if it doesn't exist
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CLAUDE_MD_DIR="''${CLAUDE_MD_DIR:-$HOME/.claude}"
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mkdir -p "$CLAUDE_MD_DIR"
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if [[ ! -f "$CLAUDE_MD_DIR/CLAUDE.md" ]]; then
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cp ${claudeMd} "$CLAUDE_MD_DIR/CLAUDE.md"
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fi
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exec ${exePath} "$@"
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'';
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};
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packages.claude = claude.wrapper;
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};
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}
+300
wrapperModules/claude-code/flake-module.nix
+300
wrapperModules/claude-code/flake-module.nix
···
1
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{ self, ... }:
2
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{
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flake.wrapperModules.claude-code =
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{
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config,
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lib,
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...
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}:
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let
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pkgs = config.pkgs;
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jsonFormat = pkgs.formats.json { };
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+
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# Assemble a single Claude Code plugin directory containing skills,
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# commands, and agents. Claude Code discovers a directory as a plugin
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# when it contains `.claude-plugin/plugin.json`.
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pluginDir =
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pkgs.runCommand "claude-plugin-${config.pluginName}"
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{
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passthru = { inherit (config) pluginManifest; };
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}
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''
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mkdir -p $out/.claude-plugin
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cp ${jsonFormat.generate "plugin.json" config.pluginManifest} \
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$out/.claude-plugin/plugin.json
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+
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${lib.optionalString (config.skills != { }) ''
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mkdir -p $out/skills
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${lib.concatStringsSep "\n" (
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lib.mapAttrsToList (name: src: "ln -s ${src} $out/skills/${name}") config.skills
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)}
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''}
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+
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${lib.optionalString (config.commands != { }) ''
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mkdir -p $out/commands
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${lib.concatStringsSep "\n" (
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lib.mapAttrsToList (name: src: "ln -s ${src} $out/commands/${name}") config.commands
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)}
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''}
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+
40
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${lib.optionalString (config.agents != { }) ''
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mkdir -p $out/agents
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${lib.concatStringsSep "\n" (
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lib.mapAttrsToList (name: src: "ln -s ${src} $out/agents/${name}") config.agents
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)}
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''}
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+
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${lib.optionalString (config.pluginExtraFiles != { }) ''
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${lib.concatStringsSep "\n" (
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lib.mapAttrsToList (path: src: ''
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mkdir -p "$out/$(dirname ${path})"
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ln -s ${src} "$out/${path}"
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'') config.pluginExtraFiles
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)}
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''}
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'';
56
+
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# Compose a settings.json from the typed options + freeform overrides.
58
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# Order matters: typed options take precedence over freeform `settings`
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# for the keys they own, but freeform can still set anything else.
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mergedSettings = lib.foldl' lib.recursiveUpdate config.settings (
61
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lib.optional (config.mcpServers != { }) { mcpServers = config.mcpServers; }
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++ lib.optional (config.hooks != { }) { hooks = config.hooks; }
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++ lib.optional (config.permissions != { }) { permissions = config.permissions; }
64
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);
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+
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settingsFile = jsonFormat.generate "claude-settings.json" mergedSettings;
67
+
68
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levenshtein = self.packages.${pkgs.system}.levenshtein-merge;
69
+
in
70
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{
71
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_class = "wrapper";
72
+
73
+
options = {
74
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pluginName = lib.mkOption {
75
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type = lib.types.str;
76
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default = "superconfig";
77
+
description = "Name of the bundled plugin directory.";
78
+
};
79
+
80
+
pluginManifest = lib.mkOption {
81
+
type = jsonFormat.type;
82
+
default = {
83
+
name = config.pluginName;
84
+
version = "0.0.0";
85
+
description = "Nix-managed Claude Code plugin bundle.";
86
+
};
87
+
defaultText = lib.literalExpression ''
88
+
{ name = config.pluginName; version = "0.0.0"; description = "..."; }
89
+
'';
90
+
description = "Contents of `.claude-plugin/plugin.json` for the bundled plugin.";
91
+
};
92
+
93
+
skills = lib.mkOption {
94
+
type = lib.types.attrsOf lib.types.path;
95
+
default = { };
96
+
example = lib.literalExpression ''
97
+
{
98
+
websearch = ./skills/websearch;
99
+
}
100
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'';
101
+
description = ''
102
+
Skills to bundle. Each entry is a directory containing `SKILL.md`
103
+
and any helper scripts/resources. Symlinked into
104
+
`<plugin>/skills/<name>` and discovered by Claude Code automatically.
105
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'';
106
+
};
107
+
108
+
commands = lib.mkOption {
109
+
type = lib.types.attrsOf lib.types.path;
110
+
default = { };
111
+
description = ''
112
+
Slash commands. Each entry is a markdown file (or directory)
113
+
symlinked into `<plugin>/commands/<name>`.
114
+
'';
115
+
};
116
+
117
+
agents = lib.mkOption {
118
+
type = lib.types.attrsOf lib.types.path;
119
+
default = { };
120
+
description = ''
121
+
Sub-agents. Each entry is a markdown file (or directory) symlinked
122
+
into `<plugin>/agents/<name>`.
123
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'';
124
+
};
125
+
126
+
pluginExtraFiles = lib.mkOption {
127
+
type = lib.types.attrsOf lib.types.path;
128
+
default = { };
129
+
example = lib.literalExpression ''
130
+
{
131
+
"hooks/format.sh" = ./hooks/format.sh;
132
+
}
133
+
'';
134
+
description = ''
135
+
Additional files to drop into the plugin directory. Keys are
136
+
relative paths inside the plugin directory; values are paths to
137
+
symlink in. Use this for hook scripts or anything else not covered
138
+
by the typed options above.
139
+
'';
140
+
};
141
+
142
+
mcpServers = lib.mkOption {
143
+
type = jsonFormat.type;
144
+
default = { };
145
+
example = lib.literalExpression ''
146
+
{
147
+
git-mcp = {
148
+
command = "''${pkgs.git-mcp}/bin/git-mcp";
149
+
};
150
+
tmux-mcp = {
151
+
type = "stdio";
152
+
command = "''${pkgs.tmux-mcp}/bin/tmux-mcp";
153
+
args = [ ];
154
+
env = { };
155
+
};
156
+
}
157
+
'';
158
+
description = ''
159
+
MCP servers to register. Merged into `settings.json` under
160
+
`mcpServers`. Each entry follows Claude Code's MCP server schema
161
+
(stdio: `{ command, args, env }`; http/sse: `{ type, url, headers }`).
162
+
'';
163
+
};
164
+
165
+
hooks = lib.mkOption {
166
+
type = jsonFormat.type;
167
+
default = { };
168
+
example = lib.literalExpression ''
169
+
{
170
+
PreToolUse = [
171
+
{
172
+
matcher = "*";
173
+
hooks = [
174
+
{
175
+
type = "command";
176
+
command = "''${pkgs.my-permission-bridge}/bin/permission-forward";
177
+
}
178
+
];
179
+
}
180
+
];
181
+
}
182
+
'';
183
+
description = ''
184
+
Hook definitions. Shape matches Claude Code's `settings.json` hooks
185
+
field. Supported events include `PreToolUse`, `PostToolUse`,
186
+
`UserPromptSubmit`, `Stop`, `SessionStart`, `Notification`, and
187
+
`PreCompact`.
188
+
'';
189
+
};
190
+
191
+
permissions = lib.mkOption {
192
+
type = jsonFormat.type;
193
+
default = { };
194
+
example = lib.literalExpression ''
195
+
{
196
+
defaultMode = "acceptEdits";
197
+
allow = [
198
+
"Bash(nix build:*)"
199
+
"Bash(nix eval:*)"
200
+
"Bash(nix fmt:*)"
201
+
"Bash(git status:*)"
202
+
"Bash(git diff:*)"
203
+
];
204
+
deny = [ ];
205
+
ask = [ ];
206
+
}
207
+
'';
208
+
description = ''
209
+
Permission rules. Shape matches Claude Code's `settings.json`
210
+
`permissions` field. Use `allow`/`deny`/`ask` pattern lists to
211
+
short-circuit the permission flow before any hook fires.
212
+
'';
213
+
};
214
+
215
+
settings = lib.mkOption {
216
+
type = jsonFormat.type;
217
+
default = { };
218
+
description = ''
219
+
Freeform additional `settings.json` content. Merged with the
220
+
typed options above (which take precedence on conflict). Use this
221
+
for anything not covered by a dedicated option.
222
+
'';
223
+
};
224
+
225
+
claudeMd = lib.mkOption {
226
+
type = lib.types.nullOr lib.types.path;
227
+
default = null;
228
+
description = ''
229
+
Optional `CLAUDE.md` whose lines are fuzzy-merged into
230
+
`$CLAUDE_MD_DIR/CLAUDE.md` (default `~/.claude/CLAUDE.md`) on
231
+
every invocation. Only adds lines, never removes user content.
232
+
Each non-blank managed line is skipped when a line within
233
+
`claudeMdMergeThreshold` (Levenshtein ratio) already exists in
234
+
the target file.
235
+
'';
236
+
};
237
+
238
+
claudeMdMergeThreshold = lib.mkOption {
239
+
type = lib.types.float;
240
+
default = 0.15;
241
+
description = ''
242
+
Levenshtein distance ratio (distance / max-length) below which
243
+
two normalized lines are considered the same during
244
+
`claudeMd` merging. 0.0 requires exact match; higher values
245
+
tolerate more typos. Default 0.15 allows roughly one typo per
246
+
seven characters.
247
+
'';
248
+
};
249
+
250
+
pluginDir = lib.mkOption {
251
+
type = lib.types.package;
252
+
readOnly = true;
253
+
default = pluginDir;
254
+
defaultText = "<assembled plugin directory>";
255
+
description = "The assembled plugin directory passed via `--plugin-dir`.";
256
+
};
257
+
258
+
settingsFile = lib.mkOption {
259
+
type = lib.types.package;
260
+
readOnly = true;
261
+
default = settingsFile;
262
+
defaultText = "<assembled settings.json>";
263
+
description = "The assembled settings.json passed via `--settings`.";
264
+
};
265
+
};
266
+
267
+
config.package = lib.mkDefault (self.lib.halalify pkgs.claude-code);
268
+
269
+
# Always inject our plugin dir + settings file into every invocation.
270
+
# `--plugin-dir` is repeatable so users can still pass more on the CLI.
271
+
config.flags."--plugin-dir" = {
272
+
value = [ "${pluginDir}" ];
273
+
order = 100;
274
+
};
275
+
config.flags."--settings" = {
276
+
value = "${settingsFile}";
277
+
order = 101;
278
+
};
279
+
280
+
config.preHook = lib.optionalString (config.claudeMd != null) ''
281
+
CLAUDE_MD_DIR="''${CLAUDE_MD_DIR:-$HOME/.claude}"
282
+
mkdir -p "$CLAUDE_MD_DIR"
283
+
touch "$CLAUDE_MD_DIR/CLAUDE.md"
284
+
${levenshtein}/bin/levenshtein-merge merge \
285
+
${config.claudeMd} \
286
+
"$CLAUDE_MD_DIR/CLAUDE.md" \
287
+
${toString config.claudeMdMergeThreshold} \
288
+
|| echo "levenshtein merge failed; leaving CLAUDE.md untouched" >&2
289
+
'';
290
+
291
+
config.meta.maintainers = [
292
+
{
293
+
name = "lassulus";
294
+
github = "lassulus";
295
+
githubId = 621375;
296
+
}
297
+
];
298
+
config.meta.platforms = lib.platforms.all;
299
+
};
300
+
}