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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+aproxy is an Activity Pub Reverse Proxy Framework built on OpenResty (NGINX + LuaJIT). It provides a modular script system to add filtering and protection capabilities in front of ActivityPub implementations.
+
+## Development Commands
+
+### Testing
+```sh
+# Install test dependencies (only needed once)
+make testdeps
+eval (luarocks-5.1 path --bin)
+
+# Run test suite
+make test
+```
+
+The test suite uses luajit and luaunit for testing. Tests are located in the `tests/` directory.
+
+## Architecture
+
+### Core Components
+
+- **main.lua**: Entry point with two hooks:
+  - `init()`: Validates configuration at startup
+  - `access()`: Called on every request to execute the filter chain
+
+- **config.lua**: Configuration system
+  - Searches for `conf.lua` in paths: `.;/etc/aproxy` (or `$APROXY_CONFIG_PATH`)
+  - Provides schema validation framework
+  - Schema supports types: `string`, `number`, `table`, `list` (array of values)
+
+- **ctx.lua**: Request context and filter chain executor
+  - Loads scripts from config and builds `compiled_chain`
+  - Matches request URIs against script PCRE regexes
+  - Executes matching callbacks sequentially
+  - If any callback returns a status code, request is terminated with that response
+
+- **util.lua**: Lua standard library extensions
+  - `table.readonly()`: Create read-only table wrapper
+  - `table.pprint()`: Pretty-print nested tables
+  - `string.split()`: Split strings by separator
+
+### Script Module Structure
+
+Scripts live in `scripts/` and must export:
+
+```lua
+return {
+    name = 'ModuleName',
+    author = 'email',
+    title = 'Short Title',
+    description = [[Long description]],
+    version = 1,
+
+    -- Called once at startup with config
+    -- Return value becomes module state
+    init = function(cfg)
+        return state
+    end,
+
+    -- Map of PCRE regex patterns to callback functions
+    callbacks = {
+        ['/api/path'] = function(cfg, state)
+            -- Return nil to allow request
+            -- Return status_code, body to block request
+            return nil
+        end
+    },
+
+    -- Schema for validating this module's config
+    config = {
+        ['field_name'] = {
+            type = 'string|number|table|list',
+            schema = {...}, -- for table/list types
+            description = 'field description'
+        }
+    }
+}
+```
+
+**Important**: Module configs are made read-only via `table.readonly()` before being passed to callbacks. Attempting to modify them will error.
+
+### Request Flow
+
+1. OpenResty calls `aproxy.main.access()` on each request
+2. `ctx:onRequest()` iterates through `compiled_chain`
+3. For each script, check if request URI matches any callback regex
+4. Execute matching callbacks with their config and state
+5. If callback returns `(status_code, body)`, terminate request with that response
+6. If callback returns `nil`, continue to next callback
+7. If no callbacks block the request, pass through to backend
+
+### Testing Framework
+
+Tests use a mock `ngx` object (created by `createNgx()` in test.lua) that simulates OpenResty's API:
+- `ngx.var.uri`: Request URI
+- `ngx.req.get_uri_args()`: Query parameters
+- `ngx.req.get_headers()`: Request headers
+- `ngx.status`, `ngx.say()`, `ngx.exit()`: Response control
+- `ngx.re.match()`: PCRE regex matching via rex_pcre2
+
+Use `setupTest(module_path, config)` to initialize a module for testing and `setupFakeRequest(path, options)` to simulate requests.
+
+To run the test suite:
+```sh
+# needed only once ever to setup the environment
+make testdeps
+
+# run once on any new shell
+eval (luarocks-5.1 path --bin)
+
+# actually run suite
+make test
+```
+
+## Configuration
+
+The default config file (`conf.lua`) structure:
+
+```lua
+return {
+    version = 1,
+    wantedScripts = {
+        ['script_name'] = {
+            -- script-specific config matching its schema
+        }
+    }
+}
+```
+
+Scripts are loaded from `scripts/{script_name}.lua` based on keys in `wantedScripts`.