xarmian 50e0936b34 feat(collab): designated-applier protocol for external content updates (TASK-1257) (#455)
* feat(collab): designated-applier protocol for external content updates (TASK-1257)

The keystone task for CLI / API / MCP integration during co-edit
sessions. When a content update arrives via PATCH while at least one
browser tab is connected to the item's collab room, the server can't
write items.content directly — the connected tabs would silently
overwrite it on the next 5s idle flush using their (now stale) Y.Doc
state and the caller's update would be lost.

Solution: nominate one connected tab as the "designated applier",
send it a JSON control message with the new markdown, the browser
does editor.commands.setContent(markdown) which the y-tiptap binding
translates into Y.Doc updates that propagate via the regular sync
path. Items.content gets refreshed via the next 5s flush
(TASK-1261).

Architecture:

internal/collab/applier.go (new):
- ControlMessage struct — JSON envelope for applier_request /
  applier_ack frames. Carried over WebSocket TextMessage, which is
  unambiguous against y-protocol's BinaryMessage.
- ApplyExternalContent(itemID, markdown) — public entry point.
  Returns nil on ack, ErrNoActiveRoom when there's no room (caller
  falls back to direct write), ErrNoApplierAvailable when the room
  has no live conns, ErrAllAppliersTimedOut when every attempt
  expired.
- Election: pickApplier returns the longest-connected roomConn that
  hasn't already been tried, with deterministic tiebreak on conn id.
  Stable choice — longest connection has the most authoritative
  cumulative Y.Doc state, fewer flicker risks.
- Retry loop: applierMaxAttempts=2, applierFirstTimeoutVar=30s,
  applierRetryTimeoutVar=15s. The Var-suffixed names exist so test
  helpers can shrink to ms without sleeping a real minute.
- Pending-ack tracking: per-room map[requestID]*pendingApplierAck
  pairing the channel a PATCH handler is waiting on with the conn
  the ack is expected from. expectedConn check prevents an unrelated
  peer from spoofing acks for someone else's request.

internal/collab/room.go (extended):
- roomConn gains connectedAt for the election.
- readLoop branches TextMessage → handleControlMessage which decodes
  the JSON and routes applier_ack to the room's pending tracker.
  Unknown control types and malformed JSON are silently dropped so a
  bad client can't break the loop.

internal/collab/manager.go:
- Registers connectedAt on Join.
- Initialises room.pendingAcks alongside conns map.

internal/server/handlers_items.go (extended):
- handleUpdateItem now branches on input.Content != nil + s.collab
  != nil: routes through s.applyContentViaCollab; on success,
  zeros input.Content so UpdateItem's direct write is suppressed.
- Field-only PATCHes skip this branch entirely — backward-compatible.

internal/server/handlers_collab.go:
- applyContentViaCollab wraps mgr.ApplyExternalContent with
  per-error-class slog warnings so operators can see degraded
  paths (timeouts → warn; no-room / no-applier → quiet, the
  common case for non-co-edit CLI updates).
- actorIDFromRequest helper for log fields.

Tests (5 new):
- TestApplyExternalContentNoActiveRoom — sentinel error path.
- TestApplyExternalContentHappyPath — applier echo acks within ms.
- TestApplyExternalContentTimeoutsThenFails — applier never acks;
  we hit applierFirstTimeoutVar then ErrAllAppliersTimedOut.
- TestApplyExternalContentTimeoutThenSecondAcks — first applier
  silent, retry picks second-longest-connected, succeeds.
- TestApplyExternalContentRejectsAckFromUnexpectedConn — defence-
  in-depth: peer B forges an ack for peer A's request; the room's
  expectedConn check rejects it; ApplyExternalContent runs to
  timeout instead of being satisfied by the forgery.

All tests pass under -race. Full suite green.

Parent: PLAN-1248. Phase 1 — Backend foundation.

* fix(collab): clean pendingAcks on success + expires_at on applier_request per Codex review (round 1)

P2 #1: ApplyExternalContent retained the per-request pendingAcks
entry on success. Each successful external update therefore
leaked a request_id + channel + expected-conn pointer for the
remainder of the room's lifetime — across long-lived sessions
the map would grow without bound. Add cancelPendingAck to the
ack-success path so the entry is released as soon as the request
completes. Test added (TestApplyExternalContentCleansPending-
AcksOnSuccess) drives 5 successful applies and asserts the
pendingAcks map is empty afterwards.

P2 #2: applier_request had no client-enforceable expiry, so a
backgrounded tab could process a stale request 60s later and
overwrite newer edits with old markdown after the server had
already retried with a different applier (or fallen back to
direct write). Add ExpiresAtMillis to the ControlMessage
envelope, populated per attempt with `now + timeouts[attempt]`.
The browser-side handler (TASK-1263) is responsible for the
client-side Now() check before applying — without that check
the field is documentation-only. Added test
(TestApplyExternalContentSendsExpiresAt) regression-tests the
server stamp.

Server-side cleanup is also reinforced: cancelPendingAck on
timeout (already present) means a late ack from a timed-out
applier is rejected at the room layer (entry is gone). The
expires_at_millis is the second line of defence for the case
where the browser sends the Y.Doc setContent BEFORE the ack —
the request must not be applied at all.
2026-05-08 16:30:39 -04:00
2026-03-26 01:52:36 +00:00
2026-03-26 01:52:36 +00:00

Pad

Project Management for the agent era.

CI Release Go Report Card Container image on GHCR License GitHub Sponsors


One binary. Local-first. No accounts required. Pad gives you a CLI, a web UI, and an AI agent skill — all backed by SQLite, all running on your machine. Your project data never leaves your laptop.

Pad dashboard showing collection summaries, active work, an active plan with progress, and a recent activity feed

Quick Start

brew install PerpetualSoftware/tap/pad
cd your-project
pad init                    # configure, auth, workspace, AI skill — all in one
pad server open             # opens the web UI at localhost:7777

pad init is the smart entry point — it auto-detects what's needed, walks you through each step, and is safe to re-run anytime (it skips finished steps and prints a status summary).

Then, in a fresh agent session in your project, say:

use pad to get IDEA-1

Your new workspace ships with a thoughtful first idea — IDEA-1 — that the agent reads and uses to help you get set up around your actual project. It's the fastest way to go from empty workspace to "okay, this is mine."

Why Pad?

Tools like Linear, Jira, and Notion are built for teams on the cloud. Pad is built for developers on their machine — and for the AI agents working alongside them.

Pad Linear / Jira Notion
Setup pad init Create account, invite team, configure Create account, pick template
AI agents Native /pad skill for 7+ tools Third-party integrations Third-party integrations
Data Local SQLite, you own it Their cloud Their cloud
Offline Full functionality Read-only cache at best Limited
CLI First-class Afterthought None
Price Free, open source Per-seat pricing Per-seat pricing

Features

For Developers

CLI that doesn't get in your way. Create tasks, search items, check status — without leaving the terminal.

pad item create task "Fix OAuth redirect" --priority high
pad item create idea "Real-time collaboration" --category infrastructure
pad item list tasks --status in-progress
pad item search "authentication"
pad project dashboard                   # Project dashboard
pad project next                        # What should I work on?
pad server info                         # How this client is connected to Pad

Web UI that stays out of your way. A clean, dark-themed interface at localhost:7777 with:

  • Board, list, and table views — drag-and-drop between status columns
  • Keyboard navigationj/k to move, Enter to open, Esc to go back, Cmd+K to search
  • Rich text editor — Tiptap-based with markdown, formatting toolbar, and auto-save
  • Wiki-links — type [[Title]] to link between items
  • Real-time updates — agent creates a task in the terminal, it appears in the browser instantly (via SSE)
  • Dashboard — collection overview, active work, plan tracking, activity feed

Pad tasks board view: kanban columns for Open, In-Progress, Done, Cancelled with task cards in each

For AI Agents

Your agent becomes a project partner. Install the /pad skill once, and your AI coding tool can read, create, and update project items through natural language.

pad agent install        # Auto-detects your tools and installs the skill

Works with Claude Code, Cursor, Windsurf, Codex, GitHub Copilot, Amazon Q, and JetBrains Junie.

Then just talk to your project:

> /pad what should I work on next?
> /pad I finished the OAuth fix
> /pad create a task to add rate limiting
> /pad let's brainstorm about the API redesign

Conventions and playbooks teach agents how your project works:

  • Conventions — trigger-based rules like "run tests before marking a task done" or "use conventional commits"
  • Playbooks — multi-step workflows like "when implementing a feature: read the spec, create a branch, write tests first, then implement"
pad item create convention "Run tests before completing tasks" \
  --field trigger=on-task-complete \
  --field scope=all \
  --field priority=must

Agents load relevant conventions automatically. All agent actions are attributed in the activity feed, so you always know what the AI changed.

Onboard agents to a new codebase:

pad workspace onboard    # Analyzes project structure, saves workspace context, and suggests conventions

Collections & Custom Fields

Pad organizes work into collections — typed containers with structured fields.

Built-in collections:

Collection Purpose
Tasks Work items with status, priority, assignee, effort, due date
Ideas Feature ideas with impact and category
Plans Project milestones with progress tracking
Docs Documentation, decisions, reference material
Conventions Project rules that guide agent behavior
Playbooks Multi-step workflows for agents to follow

Create your own with typed fields — select, text, date, number, url, relation, checkbox:

pad collection create "Bug Reports" \
  --fields "severity:select:low,medium,high,critical; browser:text; reproducible:checkbox"

Items get reference numbers automatically (TASK-5, BUG-12) and can be moved between collections with field migration.

Installation

Homebrew (macOS and Linux)

brew install PerpetualSoftware/tap/pad

Build from Source

git clone https://github.com/PerpetualSoftware/pad
cd pad
make build
cp pad ~/.local/bin/   # or /usr/local/bin/

Requires Go 1.26+ and Node.js 22+.

The go install github.com/PerpetualSoftware/pad/cmd/pad@latest path is not supported for the full Pad binary, because the web UI must be built and embedded during the source build.

Docker

docker run -p 127.0.0.1:7777:7777 -v pad-data:/data ghcr.io/perpetualsoftware/pad

This publishes Pad to localhost:7777 on the host machine, which is the recommended default for local use.

Single user, more than one device? Publish to all interfaces so you can reach Pad from your phone, tablet, or another machine on the same LAN, Tailscale network, or home VPN:

docker run -p 7777:7777 -v pad-data:/data ghcr.io/perpetualsoftware/pad

For multi-instance deployments, Pad supports Postgres + Redis via docker-compose.yml — see docs/deployment.md for the full setup.

Binary Download

Pre-built binaries for macOS, Linux, and Windows are available on the releases page.

Getting Started

1. Set up Pad

cd ~/projects/myapp
pad init "My App"

pad init is the smart entry point that handles everything in one command:

  • Configures this client's connection (local server, remote, or Docker)
  • Auto-starts the local server
  • Creates the first admin account on a fresh local install (Docker / remote hosts run pad auth setup on the server instead)
  • Logs you in if needed
  • Creates or links a workspace for the current directory (writes .pad.toml)
  • Installs the /pad skill for any AI tools detected in the project

Run from your project root. Safe to re-run anytime — it skips finished steps and prints a status summary if nothing's needed.

Choose a template with --template, or omit it for an interactive picker grouped by category (Software / People / …):

pad workspace init --list-templates                   # See the full catalog grouped by category
pad init "My App" --template scrum                    # Scrum-style with sprints
pad init "My App" --template product                  # Product management focused
pad init "My Hiring" --template hiring                # Company-side: requisitions, candidates, interview loops, feedback
pad init "Job Search" --template interviewing         # Candidate-side: applications, interviews, companies, contacts

Pad ships templates for software (startup / scrum / product), people workflows (hiring, interviewing), and has reserved categories for research, content, operations, and personal use so the same project-management primitives fit well beyond code projects.

2. Start working

# From the CLI
pad item create task "Set up CI pipeline" --priority high
pad item create idea "Add WebSocket support" --category infrastructure
pad project dashboard

# From the web UI
pad server open              # Opens localhost:7777 in your browser

# From your AI agent
# Just use /pad in Claude Code, Cursor, etc.

3. Teach your agents the rules

pad workspace onboard        # Auto-analyze project, save workspace context, and suggest conventions
# Or browse the convention library
pad library list --type conventions  # Pre-built conventions you can adopt
pad library list --type playbooks    # Pre-built multi-step workflows

4. Optional — connect a desktop AI app via MCP

Pad ships an MCP (Model Context Protocol) server so Claude Desktop, Cursor, or Windsurf can manage items, plans, ideas, and dependencies as native tools, read workspace state by URL, and load multi-step workflows as prompts.

pad mcp install claude-desktop   # or: cursor, windsurf, --all
# Restart the client; pad shows up as the "pad" MCP server.

Tool catalog (v0.2) — eight resource × action tools, no flat verb explosion:

Tool Actions
pad_item create, update, delete, get, list, move, link, unlink, deps, star, unstar, starred, comment, list-comments, bulk-update, note, decide
pad_workspace list, members, invite, storage, audit-log
pad_collection list, create
pad_project dashboard, next, standup, changelog
pad_role list, create, delete
pad_search query
pad_meta server-info, version, tool-surface
pad_set_workspace session-default workspace pinning

Plus resources at pad://workspaces, pad://workspace/{ws}/dashboard, pad://workspace/{ws}/items, pad://workspace/{ws}/items/{ref}, pad://workspace/{ws}/collections, and pad://_meta/version.

Stability contract — two version constants, both advertised in the initialize handshake under capabilities.experimental.padCmdhelp and capabilities.experimental.padToolSurface (and queryable at pad://_meta/version):

  • cmdhelp_version: "0.1" — CLI help-tree contract (used at dispatch time)
  • tool_surface_version: "0.2" — MCP tool catalog contract

External agents pin against these so a future rename doesn't break them silently. Errors come back as structured envelopes ({error: {code, message, hint, available_workspaces, ...}}) with a closed eight-code taxonomy.

Full guide at getpad.dev/mcp/local — install paths, action enums per tool, error taxonomy, troubleshooting.

CLI Reference

pad auth configure                    Configure how this client connects to Pad
pad auth setup                        Initialize the first admin account
pad auth login                        Sign in
pad auth whoami                       Show current user

pad server start                      Start the Pad API server
pad server stop                       Stop the Pad server
pad server info                       Show client, connection, and local server status
pad server open                       Open web UI in browser

pad workspace init [name]             Initialize workspace in current directory
pad workspace link <workspace>        Link current directory to an existing workspace
pad workspace list                    List all workspaces
pad workspace switch <workspace>      Switch active workspace
pad workspace context                 Show structured workspace context
pad workspace context set --file X    Update structured workspace context from JSON
pad workspace onboard                 Analyze project, save workspace context, and suggest conventions
pad workspace members                 List workspace members
pad workspace invite <email>          Invite a workspace member
pad workspace join <code>             Accept an invitation
pad workspace export                  Export workspace data
pad workspace import <file>           Import workspace data

pad project dashboard                 Project dashboard
pad project next                      Recommended next task
pad project ready                     Query actionable next items
pad project stale                     Query stalled or attention-worthy items
pad project standup [--days N]        Daily standup report
pad project changelog [--days N]      Release notes from completed items
pad project watch                     Real-time activity stream
pad project reconcile                 Reconcile item and PR state

pad item create <coll> "title"        Create item (task, idea, plan, doc, ...)
pad item list [collection]            List items (filters: --status, --priority, --all)
pad item show <ref>                   Show item detail
pad item update <ref>                 Update item fields
pad item delete <ref>                 Delete item
pad item move <ref> <collection>      Move item between collections
pad item edit <ref>                   Open item in $EDITOR
pad item search "query"               Full-text search across all items
pad item comment <ref> "text"         Add comment to an item
pad item comments <ref>               View item comments
pad item note <ref> "summary"         Append an implementation note to an item
pad item decide <ref> "decision"      Append a decision log entry to an item
pad item block <src> <target>         Create dependency
pad item blocked-by <item> <blk>      Mark item as blocked
pad item deps <ref>                   Show dependencies
pad item unblock <src> <target>       Remove dependency
pad item related <ref>                Show direct relationships for an item
pad item implemented-by <ref>         Show incoming implementers for an item
pad item bulk-update --status X       Batch update multiple items

pad collection list                   List collections with item counts
pad collection create <name>          Create a custom collection

pad library list                      Browse convention and playbook library
pad library activate <title>          Activate a convention or playbook

pad agent install [tool]              Install /pad skill for AI coding tools
pad agent status                      Show supported tools and installation status
pad agent update                      Update installed tool integrations

pad github link [item-ref]            Link current branch's PR to item
pad github status [item-ref]          Show PR status for linked items
pad github unlink <item-ref>          Remove PR link from item

pad webhook list             List workspace webhooks
pad webhook create <url>     Create webhook

All commands accept --format json for machine-readable output and --workspace to target a specific workspace.

Authentication

Pad runs without authentication by default for frictionless local use. For local installs, pad init creates the first admin account inline. The lower-level commands are useful when you're hosting a Pad server (Docker / remote) and need to set up auth on the server host directly:

pad auth setup         # Initialize the first admin account (server host, non-local mode)
pad auth login         # Sign in
pad auth whoami        # Show current user
pad auth logout        # Sign out

Once a user exists, all API requests and web UI access require authentication. Credentials are stored in ~/.pad/credentials.json. Multiple users can be invited to workspaces with role-based access control (owner, editor, viewer).

pad workspace members               # List workspace members
pad workspace invite user@example.com
pad workspace join <code>

Architecture

┌──────────────────────────────────────────────┐
│              pad (single binary)              │
│                                               │
│  ┌──────────┐  ┌──────────┐  ┌────────────┐  │
│  │   CLI    │  │  REST    │  │  Embedded  │  │
│  │ (Cobra)  │  │  API     │  │  Web UI    │  │
│  └────┬─────┘  └────┬─────┘  │ (SvelteKit)│  │
│       │    HTTP      │        └────────────┘  │
│       └──────────────┤                        │
│                ┌─────▼─────┐                  │
│                │  SQLite   │                  │
│                │  + FTS5   │                  │
│                └───────────┘                  │
└───────────────────────────────────────────────┘
  • Go backend — chi router, SQLite via modernc.org/sqlite (pure Go, no CGO), FTS5 full-text search, SSE for real-time updates
  • SvelteKit frontend — Svelte 5, Tiptap editor, drag-and-drop, adapter-static, embedded via go:embed
  • Single binary — serves the API and web UI, runs on macOS, Linux, and Windows
  • Workspace-per-project — each project gets its own workspace linked by a .pad.toml file

All data lives in ~/.pad/pad.db. Your data. Your machine. No telemetry, no cloud, no accounts required.

Contributing

See CONTRIBUTING.md for the development guide.

make build      # Build web UI + Go binary
make test       # Run Go tests
make dev-web    # SvelteKit dev server with hot reload
make install    # Build, install to ~/.local/bin, restart server

Security

See SECURITY.md for reporting vulnerabilities.

License

Apache License 2.0

Languages
Go 65.2%
TypeScript 21.3%
Svelte 12.9%
Shell 0.3%
CSS 0.1%