PartyLayer — Open-Source Wallet Abstraction Layer for Canton #9 - Milestone 1 — Application-Layer Developer Tooling

[pedrodneves]

Milestone 1 — Application-Layer Developer Tooling

Estimated Delivery: 3 weeks | Funding: 100,000 CC

Effort Rationale: Approximately 3 weeks of full-team engineering effort distributed across @partylayer/session lifecycle and resilience layer (~25%), multi-framework CLI scaffolding (~20%), @partylayer/testing mock provider and harness implementation (~20%), PartyLayer Studio interactive workbench (~20%), and Pattern Cookbook authoring (~15%). The funding allocation reflects implementation effort weighted toward developer-facing artifacts that establish a reliable onboarding baseline for the application-layer surface, anchored by the session resilience foundation that subsequent milestones build upon.

Deliverables:

@partylayer/session — Session Lifecycle & Resilience Layer

A production-grade session management layer that sits above the Canton dApp SDK's transport primitives, handling the stateful concerns every Canton dApp currently rebuilds independently:

• Persistent session restore across page reloads via encrypted storage (Web Crypto API AES-GCM, localStorage and IndexedDB backends)
• Multi-tab synchronization via BroadcastChannel — disconnect in one tab propagates to all open tabs of the same dApp
• Party-switch detection — when the user changes the primary party in their wallet, dApp state is invalidated and re-fetched automatically
• Network and synchronizer change handling with cache invalidation and reconnect orchestration
• Automatic reconnect with exponential backoff and configurable retry policies for transient network failures
• Session expiry detection and graceful re-authentication flows that preserve in-flight transaction state
• useSession, useAccount, useAccountEffect hooks for React and equivalent composables for Vue, providing reactive access to session, primary account, and lifecycle events
• Session schema migration helpers for backward-compatible storage upgrades across SDK versions
• Origin-bound session isolation preventing cross-site session leakage

This layer operates strictly above @canton-network/dapp-sdk, consuming its connect, disconnect, status, and statusChanged primitives and adding the stateful resilience patterns that wallet-side transport does not provide.

npx create-partylayer-app — Multi-Framework Application Scaffolder

Four framework-aware boilerplates, each pre-wired with PartyLayer's application-layer patterns:

• React + Vite template — PartyLayer Provider, TanStack Query Client, pre-configured hooks, themed components wired
• Next.js App Router template — Server Components hydration via cookieStorage SSR pattern, route-level wallet gates, server-side party fetching
• Vue 3 + Nuxt 3 template — composables with API parity to React hooks, Pinia store integration, SSR hydration
• Vanilla JS template — framework-agnostic core for legacy frontends or progressive enhancement

Each template ships with a working transaction lifecycle UI, mock wallet setup from @partylayer/testing, session resilience pre-configured via @partylayer/session, and CIP-0103 conformance test integration.

@partylayer/testing v1.0 — Application-Layer Testing Harness

• Mock CIP-0103 wallet provider with configurable response scenarios (connect rejection, insufficient traffic, synchronizer error, transaction timeout)
• Simulated transaction lifecycle with controllable phase transitions for testing isPreparing → isSubmitting → isConfirming → isFinalized states
• Session lifecycle simulation utilities (forced session expiry, party-switch events, multi-tab disconnect propagation, reconnect scenarios)
• TanStack Query test utilities for asserting cache state, query invalidation, and optimistic update rollback
• Offline integration test utilities — no DevNet dependency required for unit tests

PartyLayer Studio — Interactive Pattern Workbench

An in-browser sandbox built on Sandpack that runs PartyLayer code without local installation:

• Live code editor with PartyLayer types pre-loaded — IntelliSense for all hooks, composables, and components
• Mock wallet driver integrated — simulate any CIP-0103 method response without a real wallet
• Embedded React Query DevTools showing live cache state, query keys, invalidations, and refetch triggers
• Transaction lifecycle stepper with pause/resume controls for walking through state transitions and rollback simulation
• Session resilience scenarios — multi-tab sync demonstration, party-switch invalidation walkthrough, reconnect-after-expiry replay
• Framework toggle — switch the same example between React, Vue, and Vanilla JS variants
• Scenario library — pre-built scenarios for multi-wallet switching, optimistic update rollback, CIP-0104 cost preview, synchronizer failover

PartyLayer Pattern Cookbook

Pattern-oriented cookbook of runnable patterns for common application-layer problems:

• Persistent session restore on page reload via @partylayer/session
• Multi-tab synchronization via BroadcastChannel
• Wallet-switch-safe state with useAccountEffect-style flow
• Automatic reconnect with exponential backoff after network interruption
• Optimistic transaction states with rollback (useChoice + onMutate snapshot/restore)
• Query invalidation tied to update stream events
• SSR hydration in Next.js App Router via cookieStorage
• CIP-0104 cost preview before signing
• Multi-party transaction composition with typed actAs/readAs accessors
• Suspense-driven loading boundaries via useSuspenseQuery

Each entry includes a runnable Studio scenario, code snippet, and "when not to use this pattern" guidance.

Updated npm releases and documentation publishing.

Acceptance Criteria:

• @partylayer/session v1.0 published to npm with encrypted persistent storage, multi-tab BroadcastChannel synchronization, party-switch detection, automatic reconnect with exponential backoff, session expiry handling, and useSession/useAccount/useAccountEffect hooks for React and equivalent composables for Vue, validated through integration tests covering at least eight session lifecycle scenarios
• npx create-partylayer-app CLI published to npm with semantic versioning, supporting React + Vite, Next.js App Router, Vue 3 + Nuxt 3, and Vanilla JS templates
• All four scaffolded templates produce a working PartyLayer integration that passes the CIP-0103 conformance runner and ships with pre-wired TanStack Query Client, Pinia integration where applicable, SSR cookieStorage configuration, and @partylayer/session resilience layer
• @partylayer/testing v1.0 published to npm with mock wallet provider supporting configurable failure scenarios, simulated transaction lifecycle, session lifecycle simulation utilities, and TanStack Query test utilities
• PartyLayer Studio deployed publicly with Sandpack-based code editor, embedded React Query DevTools, transaction lifecycle stepper, framework toggle, and a minimum of six pre-built scenarios including at least two session resilience walkthroughs
• Pattern Cookbook published in the documentation site with at least eight runnable pattern entries linked to corresponding Studio scenarios
• All deliverables open-source on GitHub under the MIT license, with versioned releases and reproducible build instructions

---

Milestone	Target Deadline	Funding
Milestone 1: Application-Layer Developer Tooling	End of Week 3	100,000 CC

Originally posted by @pedrodneves in #9 (comment)

[cayvox]

Milestone 1 — Evidence

All seven acceptance criteria are met. Everything below is publicly verifiable.

1. @partylayer/session v1.0 — published

npm: @partylayer/session@1.1.1 · MIT
Encrypted persistent storage (Web Crypto AES-GCM, localStorage + IndexedDB), multi-tab
BroadcastChannel synchronization (origin-bound), party-switch detection (InvalidationEvent),
automatic reconnect with exponential backoff (computeBackoffDelay), session expiry handling
(ExpiryOptions), and useSession / useAccount / useAccountEffect hooks for React with
parity Vue composables.
→ https://www.npmjs.com/package/@partylayer/session

2. create-partylayer-app — published, 4 templates

React + Vite, Next.js App Router, Vue 3 + Nuxt 3, and Vanilla JS templates, each pre-wired with
the PartyLayer Provider, TanStack Query, the session resilience layer, and the mock wallet.
→ https://www.npmjs.com/package/create-partylayer-app

3. Templates pass CIP-0103 conformance + pre-wired stack

Each scaffolded template ships with the CIP-0103 conformance runner integration, TanStack Query
Client, Pinia (Vue), SSR cookieStorage (Next), and the @partylayer/session layer.

4. @partylayer/testing v1.0 — published

npm: @partylayer/testing@1.1.4 · MIT
Mock CIP-0103 wallet with configurable failure scenarios, simulated transaction lifecycle,
session lifecycle simulation, and TanStack Query test utilities. Powers the Studio sandboxes.
→ https://www.npmjs.com/package/@partylayer/testing

5. PartyLayer Studio — deployed publicly

Live: https://studio.partylayer.xyz
Sandpack-based editor with PartyLayer types/IntelliSense, integrated mock wallet driver, embedded
React Query DevTools, transaction lifecycle stepper, framework toggle (React / Vue / Vanilla),
and 7 runnable scenarios — including 2 session-resilience walkthroughs (reconnect, disconnect).
Exceeds the ≥6 (incl. ≥2 resilience) bar.

6. Pattern Cookbook — published

Live: https://partylayer.xyz/docs/cookbook
9 runnable recipes, each linked to its Studio scenario with a "when not to use" note. Exceeds the
≥8 bar.

7. MIT + versioned releases + reproducible builds

14 packages published under @partylayer/* with versioned releases and CHANGELOGs; full source MIT-licensed.
→ Source: https://github.com/PartyLayer/PartyLayer
→ Commits: https://github.com/PartyLayer/PartyLayer/commits/main
→ Merged PRs: https://github.com/PartyLayer/PartyLayer/pulls?q=is%3Apr+is%3Aclosed

---

Beyond Scope — Ecosystem Work & Partnerships (delivered during M1)

The following was not part of the contracted M1 scope but shipped during the milestone:

• WalletConnect integration — @partylayer/adapter-walletconnect published (wraps the official @canton-network/dapp-sdk WalletConnect transport), added to the verified wallet registry. Covered by CantonNews: https://cantonnews.org/partylayer-integrates-walletconnect-to-expand-canton-wallet-connectivity · announcement: https://x.com/partylayerkit/status/2064287376650764650
• Walley — fully CIP-0103-native integration — the self-custody Canton wallet by K2F Labs, bridged via its official @k2flabs/walley-dapp-sdk and added to the registry (8th wallet). https://x.com/walley_app/status/2066678989234507819
• Send — partnership + full CIP-0103 support — Send was already integrated; during M1 we also shipped its fully CIP-0103-supported integration. https://x.com/Send/status/2064799766635033052
• OneSwap — adoption — OneSwap adopted PartyLayer for its wallet-connectivity layer.
• CantonNews — Featured Project — https://cantonnews.org/projects/partylayer
• Canton Ecosystem directory — listed under Developer Tools: https://www.cantonecosystem.com
• Coverage via LunarStrategy — https://x.com/LunarStrategy/status/2066428011134787975

A full M1 completion report (PDF) with the above is also attached in the Slack thread.

[hythloda]

/vote

[git-vote]

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[hythloda]

Please note the partyID that these payments will go was given as Dualis-validator-1::122006c3436ad4b7bb6b220e2e7cbfdd55b13f92a6ea6a50dba01ff70fffc100066b
@cayvox let me know if it is otherwise

[cayvox]

Yes, that is the correct partyID. Thank you.

[joel-da]

I checked all Milestone 1 evidence points. Everything looks good to me

[shaul-da]

Following up from the voting committee meeting, I can confirm that the Digital Asset team has also reviewed CIP-103 integration. I'm voting "yes" on the milestone

[hythloda]

/check-vote