Klink

A non-custodial Solana smart-wallet for AI agents. On-chain policy DSL · spend caps · allowlists · audit trail by default.

Live: app.klinkdotfun.live · API: api.klinkdotfun.live · Agent skill: skill.md

The problem

AI agents are getting wallets faster than they're getting guardrails. Today's options are bad:

Hand them a hot key. One prompt injection drains the wallet (cf. the Drift agent-wallet incident).
Custodial SaaS wallets (Locus / Skyfire on Base). Server-side policy. Regulator exposure. You trust the provider's runtime, not the chain.
Squads v4 spend limits. Human-multisig shaped — not built for one-human / one-agent / many-API-calls-per-minute.

What's missing is a Solana-native primitive where the policy lives on-chain and the agent never holds keys that can drain the vault.

What Klink does

Klink is a three-actor wallet with a hard trust boundary:

Actor	Holds	Authority	If credential leaks
Human owner	Phantom keypair (on-device)	Master — configures policy, funds wallet, revokes sessions	Total loss (same as any Solana wallet)
Backend	Session keypair (encrypted at rest, AES-256-GCM)	Delegated co-signer, subject to on-chain policy	Bounded by `daily_cap` × time-to-revoke + recipient/program allowlists
Agent	Bearer API key only	Zero on-chain power; HTTP-only to the backend	Bounded by the session it's bound to; revoke-from-dashboard

The agent never crosses below the backend. The session keypair never leaves the backend. The owner key never leaves the human's device. The Anchor program reverts any tx that violates the on-chain policy floor.

Features

On-chain policy floor. max_per_tx, daily_cap, recipient allowlist (10 slots), program allowlist, session expiry, max_deployed_fraction_bp — all enforced by the agent_wallet Anchor program. Tx reverts on violation, no exceptions.
Off-chain rich rules. URL allowlist + time-of-day windows enforced by the backend before signing.
Audit-by-default. Solana tx history is the source of truth — free, immutable, queryable from any RPC. Off-chain enrichment adds allow/deny reasons for denied attempts.
Manual Kamino yield. Owner-triggered deposit/withdraw to the Kamino main USDC reserve via CPI. No background workers acting on user funds.
Two funding paths. Direct USDC transfer (any Solana wallet) and Dodo Payments fiat-in via a treasury bridge with idempotent webhooks.
Service spending. Curated mpp.dev catalog (proxied, the catalog ships with Klink) and user-registered x402 endpoints with sign-only relay — agent quotes the upstream 402, backend signs, you forward the proof.
Agent skill. A self-onboarding skill.md lets an LLM-agent integrate Klink without human-authored glue.
Typed TypeScript SDK. @klink/sdk wraps every agent-authenticated endpoint with zero runtime deps.

Architecture

Three layers, three actors, hybrid policy: hard limits on-chain, rich rules off-chain.

flowchart LR
    H[Human owner<br/>Phantom]
    B[Backend<br/>session keypair]
    A[Agent<br/>API key]

    subgraph CP[Control plane: HTTP API + Postgres + Redis]
        direction TB
        API[HTTP /v1/* endpoints]
        POLICY[Off-chain policy<br/>URL + time-of-day]
        AUDIT[Audit log<br/>allow + deny]
    end

    subgraph CH[On-chain: Anchor program agent_wallet]
        direction TB
        VAULT[Vault PDA<br/>seeds=vault,owner]
        SESSION[Session PDA<br/>seeds=session,vault,sk]
        VALIDATOR[Validator<br/>reverts on violation]
    end

    KAMINO[(Kamino<br/>USDC reserve)]

    H -->|Phantom signs<br/>owner-only ops| API
    B -->|session signs<br/>spend tx| API
    A -->|Bearer api_key| API

    API --> POLICY
    API --> AUDIT
    API -->|build + submit tx| VALIDATOR

    VALIDATOR --> VAULT
    VALIDATOR --> SESSION
    VAULT -.->|deposit / withdraw CPI| KAMINO

Full architecture write-up: gitbook/architecture/overview.md. Design spec: docs/specs/2026-04-28-agent-wallet-design.md.

Spend flow (the hot path)

Agent calls POST /v1/spend/... with Authorization: Bearer <api_key>.
Backend resolves the wallet + session, runs off-chain policy (URL allowlist, time window).
Backend builds the typed instruction and signs with the session keypair.
Submits to Solana — the agent_wallet program re-checks every on-chain rule and reverts on violation.
Backend writes the off-chain audit row (allow or deny with reason).

Tech stack

Layer	Stack
On-chain	Rust · Anchor 1.0 · Solana 3.x · USDC (SPL) · Kamino CPI
Backend (`apps/api`)	Bun · TypeScript · Express · Drizzle ORM · Postgres · Redis
Dashboard (`apps/web`)	Next.js 14 (App Router) · React · Tailwind · shadcn/ui · `@solana/wallet-adapter` · SWR
SDK (`packages/sdk`)	TypeScript · zero runtime deps · injectable `fetch` for tests
Tooling	Bun workspaces · Biome (lint/format) · drizzle-kit · puppeteer (e2e)

Repo layout

.
├── programs/agent_wallet/      Anchor program (Rust) — vault PDA, sessions, transfer_usdc, Kamino CPI
├── apps/
│   ├── api/                    Bun + Express backend, /v1/* surface, off-chain policy, Dodo webhook
│   └── web/                    Next.js 14 dashboard, SIWS auth, sessions/allowlist editor, audit, yield
├── packages/sdk/               @klink/sdk — typed TS client for AI-agent developers
├── docs/
│   ├── specs/                  Frozen design spec (source of truth on architecture)
│   ├── architecture/           HTTP API surface, deeper notes
│   ├── runbooks/               Dev environment, deploys, team collaboration
│   └── memos/                  Decision memos
├── gitbook/                    Public docs site source (concepts, architecture, services, skill.md)
├── migrations/                 SQL migrations
├── scripts/                    Repo automation
├── TODO.md                     Async task board — claim T-XXX before starting
├── CLAUDE.md / AGENTS.md       Conventions for AI contributors
└── CONTEXT.md                  Strategic framing + locked architecture decisions

Live links

Surface	URL
Dashboard (humans)	https://app.klinkdotfun.live
HTTP API (agents)	https://api.klinkdotfun.live
Agent skill (LLM-readable)	https://app.klinkdotfun.live/skill.md
Services catalog (markdown)	https://app.klinkdotfun.live/services/mpp.md
Devnet program id	`DPPE8TAuw5qyWbw5MqcXcAtH2d5RYF5XBXTiN2pKzM3L`

Quickstart (developers)

Prerequisites: Bun ≥ 1.1, Rust + Solana CLI + Anchor 1.0 (only if you touch the program), Postgres 15, Redis. Full setup in docs/runbooks/dev-environment.md.

git clone https://github.com/manjeetsharma0796/klink.git
cd klink
bun install

# Backend (http://localhost:3000)
cp apps/api/.env.example apps/api/.env
# edit DATABASE_URL + REDIS_URL + JWT_SECRET
bun --filter @klink/api dev

# Dashboard (http://localhost:3030)
cp apps/web/.env.local.example apps/web/.env.local
bun --filter @klink/web dev

# Run all tests
bun --filter '*' test

SDK example — give an agent a wallet in 10 lines

import { KlinkClient } from "@klink/sdk";

const klink = new KlinkClient({
  baseUrl: "https://api.klinkdotfun.live",
  apiKey: process.env.KLINK_API_KEY!, // generated in the dashboard
});

// 1) Direct on-chain transfer (subject to caps + allowlist)
await klink.spendTransfer({
  recipient: "9muAwR8a4LEgFGLNPfoUHhJrfLmtkXFBvpBQCx2GLVTU",
  amount: 5_000_000,           // 5 USDC (base units)
  memo: "invoice-2026-05-12",
});

// 2) Pay a curated mpp.dev service with a hard quote ceiling
await klink.spendService({
  slug: "anthropic-claude",
  path: "/v1/messages",
  method: "POST",
  body: { model: "claude-haiku-4.5", messages: [/* ... */] },
  max_amount: 10_000,          // 0.01 USDC ceiling
});

// 3) Manual yield
await klink.yieldDeposit({ amount: 100_000_000 });

Full SDK docs: packages/sdk/README.md.

Roadmap

Milestone	Status
Design spec frozen	✅ done — `docs/specs/2026-04-28-agent-wallet-design.md`
Anchor program (`agent_wallet`) on devnet	✅ deployed — `DPPE8TAuw5qyWbw5MqcXcAtH2d5RYF5XBXTiN2pKzM3L`
Backend `/v1/*` surface	✅ live — `api.klinkdotfun.live`
Dashboard (SIWS, sessions, allowlist, audit, yield, fund)	✅ live — `app.klinkdotfun.live`
TypeScript SDK (`@klink/sdk`)	✅ in-tree, npm publish pending
Kamino main USDC reserve (manual)	✅ devnet
Dodo Payments fiat-in (devnet)	✅ wired
External audit (`T-115`)	⏳ pending — gating mainnet deploy
Mainnet	⏳ post-audit
Auto-yield / JIT liquidity	⏳ v2 (explicitly out of MVP scope)
CLI · Python SDK · React Native	⏳ v2

Active board: TODO.md. One in-progress claim per contributor.

Hackathon — Solana Frontier (Colosseum)

Klink is built as a 60-day MVP for the Solana Frontier hackathon — the wallet/infra primitive that turns autonomous agents into safe spenders on Solana.

Sponsor integrations

Sponsor	How Klink uses it
Phantom	Sign-in-with-Solana (SIWS) for the human owner. Every owner-only op (init vault, add/revoke session, set policy, yield, fund) is signed by Phantom on the human's device; the backend never holds the owner key.
Kamino Finance	Owner-triggered `kamino_deposit` / `kamino_withdraw` CPIs into the main USDC reserve. On-chain `max_deployed_fraction_bp` guarantees a liquid spend buffer can't be over-deployed.
Dodo Payments	Card → USDC fiat-in via a treasury bridge. Idempotent webhook credits the vault's USDC ATA from a hot treasury wallet on charge.succeeded.
mpp.dev / x402	Two surfaces: curated mpp.dev catalog (Klink proxies the 402 quote → sign → forward dance) and user-registered x402 endpoints (sign-only relay, agent forwards the payment-proof header).

Contributing

This is a docs-first monorepo with an async task board. To pick up work:

Read CLAUDE.md → CONTEXT.md → docs/specs/2026-04-28-agent-wallet-design.md.
Read the collaboration protocol — docs/runbooks/team-collaboration.md.
Open TODO.md, pick a Status: pending task with no unresolved deps, claim it.
Every commit + PR references its T-XXX task id.

Working with Claude Code

The repo's task workflow is built around short prompts to Claude Code. You merge on GitHub; almost everything else is one line. Claude auto-loads CLAUDE.md, CONTEXT.md, TODO.md, and the runbooks.

Goal	Say
See what's unblocked for me	`what's unblocked for me?`
Claim a task	`claim T-105`
Implement a claimed task	`do T-105` (or `implement T-105`)
Continue after you merged a PR	`merged`
Drain a batch of unblocked tasks	`complete all without blockers`
Drop your own claim	`unclaim T-105`
Override a stale claim	`override T-105 — <reason>`
Resolve a merge conflict	`fix the conflict on PR <#>`
Show project + dev tally	`give me the leaderboard`

Plain English works too. See docs/runbooks/team-collaboration.md §7 for the full protocol.

Team

Contributor	GitHub	Role
Jishnu Baruah	@jishnu-baruah	Backend, on-chain, infra
Prithwish Chatterjee	@prithwish122	Frontend, dashboard, SDK
Manjeet Sharma	@manjeetsharma0796	Frontend, deploys
Manish Barnwal	@imanishbarnwal	Design, docs

_{Roles inferred from git history — edit if you want a different framing.}

Documentation

gitbook/ — public docs (concepts, architecture, services, agent skill)
docs/specs/ — frozen design specs (source of truth on architecture)
docs/architecture/ — HTTP API surface + deeper notes
docs/runbooks/ — dev environment, deploys, collaboration
HANDOVER.md — operational gotchas (cold-start, JWT-secret traps)
DOCS_INDEX.md — full doc inventory

License

TODO: pick (MIT / Apache-2.0). Tracked as a follow-up to T-115.

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Repository files navigation

Klink

The problem

What Klink does

Features

Architecture

Spend flow (the hot path)

Tech stack

Repo layout

Live links

Quickstart (developers)

SDK example — give an agent a wallet in 10 lines

Roadmap

Hackathon — Solana Frontier (Colosseum)

Sponsor integrations

Contributing

Working with Claude Code

Team

Documentation

License

About

Releases

Packages

Contributors

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Name		Name	Last commit message	Last commit date
Latest commit History 269 Commits
.github/workflows		.github/workflows
apps		apps
docs		docs
gitbook		gitbook
migrations		migrations
packages/sdk		packages/sdk
programs/agent_wallet		programs/agent_wallet
scripts		scripts
target/deploy		target/deploy
tests		tests
.gitattributes		.gitattributes
.gitignore		.gitignore
.mcp.json		.mcp.json
AGENTS.md		AGENTS.md
Anchor.toml		Anchor.toml
CLAUDE.md		CLAUDE.md
CONTEXT.md		CONTEXT.md
Cargo.lock		Cargo.lock
Cargo.toml		Cargo.toml
DOCS_INDEX.md		DOCS_INDEX.md
HANDOVER.md		HANDOVER.md
README.md		README.md
TODO.md		TODO.md
biome.json		biome.json
bun.lock		bun.lock
package.json		package.json

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Klink

The problem

What Klink does

Features

Architecture

Spend flow (the hot path)

Tech stack

Repo layout

Live links

Quickstart (developers)

SDK example — give an agent a wallet in 10 lines

Roadmap

Hackathon — Solana Frontier (Colosseum)

Sponsor integrations

Contributing

Working with Claude Code

Team

Documentation

License

About

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