What is FibX? - Fibrous Documentation

FibX is a DeFi execution layer for developers and AI agents — token swaps, transfers, balance checks, cross-chain portfolio inspection, and Aave V3 position management — across Base, HyperEVM, and Monad. One published package serves three surfaces: fibx <command> for people, fibx mcp-start for agents, and, in hosts that render MCP Apps UI, the FibX app inside the chat. It combines Fibrous aggregation for optimal swap routing with a choice of how transactions are signed: your own wallet over WalletConnect, a server-managed wallet via Privy, or a private key imported onto the machine — every path bounded by a signing policy that lives in a file you own.

Core Capabilities

The FibX App

In Claude Desktop and other hosts that render MCP Apps UI, one tool opens the whole app in the chat — wallet, balances, signing policy, and a swap form with the Fibrous route. The model opens it; you press Simulate and Swap.

Portfolio View

Consolidated cross-chain portfolio view with USD valuations, token balances, Aave collateral and debt, and total net worth across all supported chains.

Token Swaps

Optimal routing via Fibrous aggregation with configurable slippage (default: 0.5%). Supports the tokens and integrated DEX liquidity available through Fibrous on each chain.

Transfers

Send native tokens (ETH, HYPE, MON) or ERC-20 tokens to an address, with command-specific preflight and preview support.

Aave V3

Supply, borrow, repay, withdraw, and browse active markets on Base. ETH supply and repay can auto-wrap, ETH withdraw can auto-unwrap, and borrowing the ETH market returns WETH.

Agent Skills

Eleven pre-built skills that allow AI agents to check prices, authenticate, set a signing policy, inspect balances and portfolios, trade, send, manage Aave positions, verify transactions, and configure RPC endpoints — all through natural language.

How It Works

FibX runs as a CLI tool (npx fibx@latest) or as a stdio MCP server (npx fibx mcp-start). Both talk to the Fibrous aggregation stack and to the chain RPCs directly. Where a transaction is signed depends on the signing path: on the user’s phone over WalletConnect, at Privy through fibx-server, or locally with an imported key. In every case the local signing policy is checked before a signature is requested. Transaction paths use command-specific estimates or contract simulations where implemented, but those checks do not guarantee that an on-chain operation will succeed.

Supported Chains

Chain	Native Token	CLI Flag	Aave V3
Base	ETH	`--chain base`	Yes
HyperEVM	HYPE	`--chain hyperevm`	No
Monad	MON	`--chain monad`	No

Citrea was delisted by Fibrous on 2026-08-10 and withdrawn from FibX in v0.10.0. --chain citrea is refused.

Security Model

FibX moves real funds. Treat client confirmation, preview output, the signing policies, and backend credentials as separate controls; none replaces reviewing the final transaction request.

Local Signing Policy

A JSON file on the user’s machine — a native-value cap per chain, an allowed-chain list, an allowed-destination list, and an expiry — evaluated before every signature on all three signing paths. It bounds the native value of a transaction, not ERC-20 amounts encoded in calldata; allowedDestinations is what bounds where tokens may go. A refusal comes back as POLICY_BLOCKED with the rule named. See Signing paths and the local policy.

Privy Policy Scope

On the Privy path, new wallets are attached to a default-deny policy whose rules allowlist configured chain IDs and cap the native value field, evaluated by Privy at signing time on top of the local policy. Message and typed-data requests also rely on fibx-server validation. A custom WALLET_POLICY_ID is checked for existence, not compared with the default rule set.

Client Confirmation Hints

Transactional MCP tools carry the destructiveHint annotation. MCP clients may use this metadata to request confirmation, depending on the client and its configuration. The FibX app executes nothing on its own: Simulate and Swap are buttons the user presses.

Signing Modes

Over WalletConnect the wallet app approves every transaction and nothing is signed on this machine. In Privy mode, signing returns a signed payload to the CLI; the raw key is not returned, and fibx-server with the Privy app secret remains the trust boundary. In private-key mode, FibX encrypts the imported key at rest with AES-256-GCM and signs locally — there the local policy is the only bound.

Preview Limitations

--simulate and simulate=true provide no-broadcast previews for supported write paths, but the returned checks are command-specific. Gas estimates are included only where they can be calculated safely, and an Aave action preview does not perform on-chain validation. A preview does not guarantee that later execution will succeed.

The policies are defense in depth on the normal signing path, not a containment guarantee. The local policy is a file, so it is worth nothing against something that can already write to the user’s disk; the Privy app credentials authorize both signing and policy administration, so the backend that holds them is the administrative trust boundary on that path.

Typical Workflow

A typical wallet workflow follows five steps:

Choose how FibX signs

Run fibx auth setup. It presents the three paths with their trade-offs — your own wallet over WalletConnect, a Privy server wallet via email OTP, or an imported private key — and creates a session that persists across commands.

Bound what it may sign

Set a signing policy with fibx policy set. On the imported-key path this is the only limit there is; on the others it sits in front of the wallet’s own approval or Privy’s policy.

Check Funds

Query native and ERC-20 token balances on the target chain, or inspect the full cross-chain portfolio with USD valuations.

Execute

Review the amount, tokens, destination, chain, and any approval. Use the command-specific preview options where appropriate, then submit the operation on-chain. Over WalletConnect, approve it on your phone.

Verify

Check the transaction status and obtain the block explorer link.

Quick Example

# Check a price first — no wallet, no login required
npx fibx@latest quote 0.01 ETH USDC

# Choose a signing path (interactive)
npx fibx@latest auth setup

# Cap what this wallet may sign on Base
npx fibx@latest policy set base.maxValue 0.05

# Check balance on Base
npx fibx@latest balance

# View your cross-chain portfolio
npx fibx@latest portfolio

# Swap 0.01 ETH for USDC
npx fibx@latest trade 0.01 ETH USDC

# Verify the transaction
npx fibx@latest tx-status 0xabc...def

Three Ways to Use FibX

As a CLI Tool
As an MCP Server
As Agent Skills

Run commands directly in your terminal. Ideal for developers who want programmatic access to DeFi operations or need to script workflows.

npx fibx@latest portfolio --json
npx fibx@latest trade 0.05 ETH USDC --chain base --simulate

Add npx fibx mcp-start to Cursor, Claude Desktop, VS Code, Windsurf or Antigravity and the model gets 19 typed tools. In a host that renders MCP Apps UI — Claude Desktop today — asking about your wallet, a price or a swap opens the FibX app inline, pre-filled from the conversation. See MCP Configuration.

{ "mcpServers": { "fibx": { "command": "npx", "args": ["-y", "fibx", "mcp-start"] } } }

Import the fibx-skills into your AI agent’s skill registry. The agent interprets natural language prompts and maps them to the appropriate CLI commands.

User Prompt	Skill Triggered
”How much USDC for 0.1 ETH?”	`quote`
”Connect my own wallet”	`authenticate-wallet`
”Cap this wallet at 0.05 ETH”	`policy`
”What’s my wallet address?”	`wallet-info`
”Swap 0.05 ETH to USDC”	`trade`
”Check my balance on Monad”	`balance`
”Show me my portfolio”	`portfolio`
”Send 10 USDC to 0x123…”	`send`
”Supply 100 USDC to Aave”	`aave`
”I’m getting rate limit errors”	`config`

Telegram Bot

fibx-telegram-bot puts the same execution layer in a chat window. It drives the FibX MCP server, exposing capabilities such as quotes, swaps, transfers, portfolio, and Aave through natural language rather than CLI flags.

Bring your own model. Choose OpenAI, Claude or Gemini and supply your own API key. There is no shared key and no centralized inference billing; keys are encrypted at rest. /deletekey clears the provider configuration and encrypted key, FibX session/config/cache, pending authentication, and chat history; price alerts remain active.
Per-user runtime state. Every active user gets a dedicated MCP process and separate HOME/XDG paths. These processes still run under the same OS account, so this is application-level separation rather than an OS sandbox.
Price alerts. /alert ETH above 4000 notifies you once when the price is reached — no login or AI key required.

Resources

npm Package

fibx v0.10.0 — install and version history

Agent Skills

Eleven pre-built skills for AI agent integration

MCP Configuration

Connect FibX to Cursor, Claude Desktop, VS Code, Windsurf, and Antigravity — and open the FibX app in the chat

Signing Paths and Policy

Your own wallet, Privy, or an imported key — and the local file that bounds all three

MCP Registry

Listed as finance.fibrous/fibx

Telegram Bot

Chat-based DeFi execution with your own AI model

​Core Capabilities

The FibX App

Portfolio View

Token Swaps

Transfers

Aave V3

Agent Skills

​How It Works

​Supported Chains

​Security Model

Local Signing Policy

Privy Policy Scope

Client Confirmation Hints

Signing Modes

Preview Limitations

​Typical Workflow

​Quick Example

​Three Ways to Use FibX

​Telegram Bot

​Resources

npm Package

Agent Skills

MCP Configuration

Signing Paths and Policy

MCP Registry

Telegram Bot

Core Capabilities

How It Works

Supported Chains

Security Model

Typical Workflow

Quick Example

Three Ways to Use FibX

Telegram Bot

Resources