diff --git a/README.md b/README.md
index 2c55006..5aac508 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,78 @@
-# ansible-role-notarius
+# Ansible Role: Notarius
 
-Ansible role to install the Notarius application.
\ No newline at end of file
+Installs and configures [Notarius](https://gitea.maximumdirect.net/eric/notarius)
+from source on Ubuntu 26.04 (`x86_64` or `aarch64`). The role requires gathered
+facts and uses privilege escalation only for dependency installation and
+root-owned application state.
+
+## Variables
+
+```yaml
+notarius_version: v0.6.0
+notarius_repository_url: https://gitea.maximumdirect.net/eric/notarius.git
+notarius_source_dir: /usr/local/src/notarius
+notarius_binary_path: /usr/local/bin/notarius
+notarius_manage_build_dependencies: true
+notarius_go_snap_channel: 1.26/stable
+notarius_go_binary: /snap/bin/go
+notarius_config_path: /usr/local/etc/notarius/config.yml
+notarius_config_version: 4
+notarius_promptkit_profile_dir: null
+notarius_promptkit_profile_file: null
+notarius_promptkit_local_backend_endpoint: null
+notarius_promptkit_local_backend_concurrency_limit: null
+notarius_pipelines: null
+notarius_concurrency_total_llm: null
+notarius_concurrency_stage_workers_extract: null
+notarius_output_directory: null
+notarius_cache_chunk_plans_mode: null
+notarius_cache_chunk_plans_directory: null
+notarius_cache_checkpoints_enabled: null
+notarius_cache_checkpoints_directory: null
+notarius_debug_directory: null
+```
+
+When `notarius_manage_build_dependencies` is `false`, Git and the executable
+selected by `notarius_go_binary` must already be available. Otherwise, the role
+installs Git with APT and the classic Go Snap from `notarius_go_snap_channel`.
+It checks out `notarius_version` authoritatively, builds `./cmd/notarius`
+directly to `notarius_binary_path`, and rebuilds only when that checkout changes
+or the binary is absent. The source tree is recursively owned by `root:root`;
+the binary is `root:root` mode `0755`.
+
+Configuration variables map directly to Notarius's versioned YAML fields.
+Every optional value defaults to `null`, so it and any empty parent section are
+omitted and Notarius retains ownership of its built-in defaults. The role always
+emits `notarius_config_version` as `version` and writes the file as `root:root`
+mode `0644`. `notarius_pipelines` is the native mapping supplied by the caller;
+the role does not merge or rewrite it. For example, inventory can compose
+fragments in the ordinary way:
+
+```yaml
+notarius_pipelines: "{{ notarius_pipeline_group_one | combine(notarius_pipeline_group_two) }}"
+```
+
+PromptKit profile values identify profile sources or a local backend endpoint;
+they never contain credentials. Supply any credential environment variables
+outside this role.
+
+## Example
+
+```yaml
+- hosts: notarius_hosts
+  roles:
+    - role: ansible-role-notarius
+```
+
+## Validation
+
+The repository-local integration suite installs its pinned collection, runs
+syntax checking and production-profile lint, verifies the default release,
+ownership, executable output, minimal configuration, native configuration
+validation, and immediate idempotence. It mutates only the managed source,
+binary, configuration, and a private temporary directory, then leaves the
+default release and minimal configuration installed.
+
+```sh
+tests/integration
+```
diff --git a/ansible.cfg b/ansible.cfg
new file mode 100644
index 0000000..2d4c5f9
--- /dev/null
+++ b/ansible.cfg
@@ -0,0 +1,2 @@
+[defaults]
+roles_path = ..
diff --git a/collections/requirements.yml b/collections/requirements.yml
new file mode 100644
index 0000000..22c02b2
--- /dev/null
+++ b/collections/requirements.yml
@@ -0,0 +1,4 @@
+---
+collections:
+  - name: community.general
+    version: 13.3.0
diff --git a/defaults/main.yml b/defaults/main.yml
new file mode 100644
index 0000000..1d5184f
--- /dev/null
+++ b/defaults/main.yml
@@ -0,0 +1,23 @@
+---
+notarius_version: v0.6.0
+notarius_repository_url: https://gitea.maximumdirect.net/eric/notarius.git
+notarius_source_dir: /usr/local/src/notarius
+notarius_binary_path: /usr/local/bin/notarius
+notarius_manage_build_dependencies: true
+notarius_go_snap_channel: 1.26/stable
+notarius_go_binary: /snap/bin/go
+notarius_config_path: /usr/local/etc/notarius/config.yml
+notarius_config_version: 4
+notarius_promptkit_profile_dir: null
+notarius_promptkit_profile_file: null
+notarius_promptkit_local_backend_endpoint: null
+notarius_promptkit_local_backend_concurrency_limit: null
+notarius_pipelines: null
+notarius_concurrency_total_llm: null
+notarius_concurrency_stage_workers_extract: null
+notarius_output_directory: null
+notarius_cache_chunk_plans_mode: null
+notarius_cache_chunk_plans_directory: null
+notarius_cache_checkpoints_enabled: null
+notarius_cache_checkpoints_directory: null
+notarius_debug_directory: null
diff --git a/meta/argument_specs.yml b/meta/argument_specs.yml
new file mode 100644
index 0000000..5b66c1c
--- /dev/null
+++ b/meta/argument_specs.yml
@@ -0,0 +1,71 @@
+---
+argument_specs:
+  main:
+    short_description: Install and configure Notarius from source
+    options:
+      notarius_version:
+        type: str
+        required: true
+      notarius_repository_url:
+        type: str
+        required: true
+      notarius_source_dir:
+        type: path
+        required: true
+      notarius_binary_path:
+        type: path
+        required: true
+      notarius_manage_build_dependencies:
+        type: bool
+        required: true
+      notarius_go_snap_channel:
+        type: str
+        required: true
+      notarius_go_binary:
+        type: path
+        required: true
+      notarius_config_path:
+        type: path
+        required: true
+      notarius_config_version:
+        type: int
+        required: true
+      notarius_promptkit_profile_dir:
+        type: str
+        required: false
+      notarius_promptkit_profile_file:
+        type: str
+        required: false
+      notarius_promptkit_local_backend_endpoint:
+        type: str
+        required: false
+      notarius_promptkit_local_backend_concurrency_limit:
+        type: int
+        required: false
+      notarius_pipelines:
+        type: dict
+        required: false
+      notarius_concurrency_total_llm:
+        type: int
+        required: false
+      notarius_concurrency_stage_workers_extract:
+        type: int
+        required: false
+      notarius_output_directory:
+        type: str
+        required: false
+      notarius_cache_chunk_plans_mode:
+        type: str
+        required: false
+      notarius_cache_chunk_plans_directory:
+        type: str
+        required: false
+      notarius_cache_checkpoints_enabled:
+        type: bool
+        required: false
+      notarius_cache_checkpoints_directory:
+        type: str
+        required: false
+      notarius_debug_directory:
+        type: str
+        required: false
diff --git a/meta/main.yml b/meta/main.yml
new file mode 100644
index 0000000..d7f8945
--- /dev/null
+++ b/meta/main.yml
@@ -0,0 +1,18 @@
+---
+galaxy_info:
+  role_name: notarius
+  namespace: rakestraw
+  author: Eric Rakestraw
+  description: Install and configure Notarius from source
+  license: BSD-3-Clause
+  min_ansible_version: "2.18"
+  issue_tracker_url: https://gitea.maximumdirect.net/eric/ansible-role-notarius/issues
+  platforms:
+    - name: Ubuntu
+      versions:
+        - resolute
+  galaxy_tags:
+    - notarius
+    - transcript
+    - processing
+dependencies: []
diff --git a/tasks/main.yml b/tasks/main.yml
new file mode 100644
index 0000000..595c8b4
--- /dev/null
+++ b/tasks/main.yml
@@ -0,0 +1,101 @@
+---
+- name: Validate the supported platform
+  ansible.builtin.assert:
+    that:
+      - ansible_facts.distribution == "Ubuntu"
+      - ansible_facts.distribution_version == "26.04"
+      - ansible_facts.architecture in ["x86_64", "aarch64"]
+    fail_msg: Notarius supports Ubuntu 26.04 on x86_64 or aarch64.
+
+- name: Install Git
+  become: true
+  ansible.builtin.apt:
+    name: git
+    state: present
+    update_cache: true
+    cache_valid_time: 3600
+  when: notarius_manage_build_dependencies
+
+- name: Install Go
+  become: true
+  community.general.snap:
+    name: go
+    channel: "{{ notarius_go_snap_channel }}"
+    classic: true
+    state: present
+  when: notarius_manage_build_dependencies
+
+- name: Create installation parent directories
+  become: true
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: directory
+    owner: root
+    group: root
+    mode: "0755"
+  loop:
+    - "{{ notarius_source_dir | dirname }}"
+    - "{{ notarius_binary_path | dirname }}"
+    - "{{ notarius_config_path | dirname }}"
+
+- name: Check out Notarius source
+  become: true
+  ansible.builtin.git:
+    repo: "{{ notarius_repository_url }}"
+    dest: "{{ notarius_source_dir }}"
+    version: "{{ notarius_version }}"
+    force: true
+  register: notarius_checkout
+
+- name: Inspect the installed binary
+  ansible.builtin.stat:
+    path: "{{ notarius_binary_path }}"
+  register: notarius_binary
+
+- name: Build Notarius
+  become: true
+  ansible.builtin.command:
+    argv:
+      - "{{ notarius_go_binary }}"
+      - build
+      - -trimpath
+      - -ldflags
+      - "-X gitea.maximumdirect.net/eric/notarius/internal/buildinfo.Override={{ notarius_version }}"
+      - -o
+      - "{{ notarius_binary_path }}"
+      - ./cmd/notarius
+    chdir: "{{ notarius_source_dir }}"
+  environment:
+    CGO_ENABLED: "0"
+    GOTOOLCHAIN: local
+    GOWORK: "off"
+  changed_when: true
+  when: >-
+    notarius_checkout.changed or
+    not notarius_binary.stat.exists
+
+- name: Converge installed metadata
+  become: true
+  ansible.builtin.file:
+    path: "{{ item.path }}"
+    state: "{{ item.state }}"
+    owner: root
+    group: root
+    mode: "{{ item.mode | default(omit) }}"
+    recurse: "{{ item.recurse | default(omit) }}"
+  loop:
+    - path: "{{ notarius_source_dir }}"
+      state: directory
+      recurse: true
+    - path: "{{ notarius_binary_path }}"
+      state: file
+      mode: "0755"
+
+- name: Write Notarius configuration
+  become: true
+  ansible.builtin.template:
+    src: config.yml.j2
+    dest: "{{ notarius_config_path }}"
+    owner: root
+    group: root
+    mode: "0644"
diff --git a/templates/config.yml.j2 b/templates/config.yml.j2
new file mode 100644
index 0000000..0df404e
--- /dev/null
+++ b/templates/config.yml.j2
@@ -0,0 +1,61 @@
+version: {{ notarius_config_version }}
+{% if notarius_promptkit_profile_dir is not none or notarius_promptkit_profile_file is not none or notarius_promptkit_local_backend_endpoint is not none or notarius_promptkit_local_backend_concurrency_limit is not none %}
+promptkit:
+{% if notarius_promptkit_profile_dir is not none %}
+  profile_dir: {{ notarius_promptkit_profile_dir | to_json }}
+{% endif %}
+{% if notarius_promptkit_profile_file is not none %}
+  profile_file: {{ notarius_promptkit_profile_file | to_json }}
+{% endif %}
+{% if notarius_promptkit_local_backend_endpoint is not none or notarius_promptkit_local_backend_concurrency_limit is not none %}
+  local_backend:
+{% if notarius_promptkit_local_backend_endpoint is not none %}
+    endpoint: {{ notarius_promptkit_local_backend_endpoint | to_json }}
+{% endif %}
+{% if notarius_promptkit_local_backend_concurrency_limit is not none %}
+    concurrency_limit: {{ notarius_promptkit_local_backend_concurrency_limit | to_json }}
+{% endif %}
+{% endif %}
+{% endif %}
+{% if notarius_pipelines is not none %}
+pipelines: {{ notarius_pipelines | to_json }}
+{% endif %}
+{% if notarius_concurrency_total_llm is not none or notarius_concurrency_stage_workers_extract is not none %}
+concurrency:
+{% if notarius_concurrency_total_llm is not none %}
+  total_llm: {{ notarius_concurrency_total_llm | to_json }}
+{% endif %}
+{% if notarius_concurrency_stage_workers_extract is not none %}
+  stage_workers:
+    extract: {{ notarius_concurrency_stage_workers_extract | to_json }}
+{% endif %}
+{% endif %}
+{% if notarius_output_directory is not none %}
+output:
+  directory: {{ notarius_output_directory | to_json }}
+{% endif %}
+{% if notarius_cache_chunk_plans_mode is not none or notarius_cache_chunk_plans_directory is not none or notarius_cache_checkpoints_enabled is not none or notarius_cache_checkpoints_directory is not none %}
+cache:
+{% if notarius_cache_chunk_plans_mode is not none or notarius_cache_chunk_plans_directory is not none %}
+  chunk_plans:
+{% if notarius_cache_chunk_plans_mode is not none %}
+    mode: {{ notarius_cache_chunk_plans_mode | to_json }}
+{% endif %}
+{% if notarius_cache_chunk_plans_directory is not none %}
+    directory: {{ notarius_cache_chunk_plans_directory | to_json }}
+{% endif %}
+{% endif %}
+{% if notarius_cache_checkpoints_enabled is not none or notarius_cache_checkpoints_directory is not none %}
+  checkpoints:
+{% if notarius_cache_checkpoints_enabled is not none %}
+    enabled: {{ notarius_cache_checkpoints_enabled | to_json }}
+{% endif %}
+{% if notarius_cache_checkpoints_directory is not none %}
+    directory: {{ notarius_cache_checkpoints_directory | to_json }}
+{% endif %}
+{% endif %}
+{% endif %}
+{% if notarius_debug_directory is not none %}
+debug:
+  directory: {{ notarius_debug_directory | to_json }}
+{% endif %}
diff --git a/tests/converge.yml b/tests/converge.yml
new file mode 100644
index 0000000..003a20b
--- /dev/null
+++ b/tests/converge.yml
@@ -0,0 +1,6 @@
+---
+- name: Converge Notarius role
+  hosts: localhost
+  gather_facts: true
+  roles:
+    - role: ansible-role-notarius
diff --git a/tests/integration b/tests/integration
new file mode 100755
index 0000000..ba9d872
--- /dev/null
+++ b/tests/integration
@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repository_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+workspace_venv="$repository_root/../.venv"
+test_tmp=$(mktemp -d)
+chmod 0700 "$test_tmp"
+
+export ANSIBLE_COLLECTIONS_PATH="$test_tmp/collections"
+export ANSIBLE_ROLES_PATH="$(dirname "$repository_root")"
+
+inventory="$repository_root/tests/inventory"
+converge="$repository_root/tests/converge.yml"
+verify="$repository_root/tests/verify.yml"
+ansible_playbook="$workspace_venv/bin/ansible-playbook"
+default_commit=77ae132e5609916da40dcd4fcc749c000a63cbac
+
+cleanup() {
+  exit_status=$?
+  trap - EXIT
+  "$ansible_playbook" -i "$inventory" "$converge" >/dev/null 2>&1 || true
+  rm -rf -- "$test_tmp"
+  exit "$exit_status"
+}
+trap cleanup EXIT
+
+require_clean_recap() {
+  grep -Eq 'changed=0 .*failed=0' "$1"
+}
+
+cd "$repository_root"
+"$workspace_venv/bin/ansible-galaxy" collection install \
+  -r collections/requirements.yml \
+  -p "$ANSIBLE_COLLECTIONS_PATH"
+"$ansible_playbook" -i "$inventory" --syntax-check "$converge"
+"$workspace_venv/bin/ansible-lint" "$converge" "$verify"
+
+baseline_log="$test_tmp/baseline.log"
+"$ansible_playbook" -i "$inventory" "$converge" | tee "$baseline_log"
+"$ansible_playbook" -i "$inventory" \
+  -e "notarius_expected_version=v0.6.0" \
+  -e "notarius_expected_commit=$default_commit" \
+  "$verify"
+repeat_log="$test_tmp/repeat.log"
+"$ansible_playbook" -i "$inventory" "$converge" | tee "$repeat_log"
+require_clean_recap "$repeat_log"
diff --git a/tests/inventory b/tests/inventory
new file mode 100644
index 0000000..2302eda
--- /dev/null
+++ b/tests/inventory
@@ -0,0 +1 @@
+localhost ansible_connection=local
diff --git a/tests/verify.yml b/tests/verify.yml
new file mode 100644
index 0000000..c094db9
--- /dev/null
+++ b/tests/verify.yml
@@ -0,0 +1,83 @@
+---
+- name: Verify Notarius installation
+  hosts: localhost
+  gather_facts: false
+  tasks:
+    - name: Read the selected source commit
+      become: true
+      ansible.builtin.command:
+        argv:
+          - git
+          - -C
+          - /usr/local/src/notarius
+          - rev-parse
+          - HEAD
+      register: notarius_commit
+      changed_when: false
+
+    - name: Inspect source ownership
+      become: true
+      ansible.builtin.command:
+        argv:
+          - find
+          - /usr/local/src/notarius
+          - -not
+          - -user
+          - root
+          - -o
+          - -not
+          - -group
+          - root
+      register: notarius_source_ownership
+      changed_when: false
+
+    - name: Inspect binary metadata
+      become: true
+      ansible.builtin.stat:
+        path: /usr/local/bin/notarius
+      register: notarius_binary_metadata
+
+    - name: Inspect configuration metadata
+      become: true
+      ansible.builtin.stat:
+        path: /usr/local/etc/notarius/config.yml
+      register: notarius_config_metadata
+
+    - name: Read default configuration
+      become: true
+      ansible.builtin.slurp:
+        src: /usr/local/etc/notarius/config.yml
+      register: notarius_default_config
+
+    - name: Read the installed version
+      ansible.builtin.command:
+        argv:
+          - /usr/local/bin/notarius
+          - --version
+      register: notarius_version_output
+      changed_when: false
+
+    - name: Validate Notarius configuration
+      ansible.builtin.command:
+        argv:
+          - /usr/local/bin/notarius
+          - config
+          - validate
+          - --config
+          - /usr/local/etc/notarius/config.yml
+      changed_when: false
+
+    - name: Assert the installation contract
+      ansible.builtin.assert:
+        that:
+          - notarius_commit.stdout == notarius_expected_commit
+          - notarius_source_ownership.stdout == ""
+          - notarius_binary_metadata.stat.isreg
+          - notarius_binary_metadata.stat.pw_name == "root"
+          - notarius_binary_metadata.stat.gr_name == "root"
+          - notarius_binary_metadata.stat.mode == "0755"
+          - notarius_config_metadata.stat.pw_name == "root"
+          - notarius_config_metadata.stat.gr_name == "root"
+          - notarius_config_metadata.stat.mode == "0644"
+          - '(notarius_default_config.content | b64decode | from_yaml) == {"version": 4}'
+          - notarius_version_output.stdout == "notarius " ~ notarius_expected_version