Ophis

Say swap 100 USDC for ETH on Base and Ophis resolves the tokens, chain, and amount, then fills the order through a competitive solver auction that settles on-chain. It is a fork of CoW Protocol (orderbook, autopilot, driver, and baseline solver) with a natural-language intent layer over a rebranded CoW Swap UI. On Optimism, Ophis runs the whole stack under its own settlement contracts and keeps the full fee; on the other supported chains (Ethereum, Base, Arbitrum, and more) it routes through CoW Protocol's hosted network.

What that buys you on every trade:

• Gasless, MEV-protected. Orders settle in a batch auction where every trade clears at one uniform price, so sandwiches and front-running are structurally absent, not best-effort.

• Surplus stays with you. Solvers compete to beat the price you signed, and any improvement is returned to you in full. Ophis takes a flat fee on volume and zero share of your surplus.

• Non-custodial, no account, no auth. Every order is signed in your own wallet (EIP-712 or ERC-1271). Ophis never holds keys or funds and cannot move, freeze, or recover them. The signature is the only trust boundary.

• A flat, transparent fee. 0.10% (10 bps) on volume, dropping to 0.01% (1 bp) on same-chain stablecoin pairs, with a share returned monthly as WETH rebates plus an 8% referral on trades you bring.

Live across the CoW-supported chains, with its own self-hosted settlement and solver on Optimism (chain 10).

Quickstart: the Intent API

Ophis's one bespoke API turns natural language into a structured order. No key, no account, just POST your request:

curl -sS https://ophis.fi/api/intent \
  -H 'content-type: application/json' \
  -d '{"text":"swap 100 USDC for ETH on Base"}'

{
  "ok": true,
  "data": {
    "intent": "swap",
    "entities": [
      { "type": "amount",    "value": "100",  "raw": "100",  "start": 5,  "end": 8 },
      { "type": "sellToken", "value": "USDC", "raw": "USDC", "start": 9,  "end": 13 },
      { "type": "buyToken",  "value": "ETH",  "raw": "ETH",  "start": 18, "end": 21 },
      { "type": "chain",     "value": "base", "raw": "Base", "start": 25, "end": 29 }
    ]
  }
}

Map the chain slug to a chain ID and hand the user a swap deep link to review and sign. The endpoint only normalizes text, it never places, signs, or executes a trade. It is rate-limited to 30 requests per minute per IP; non-browser callers (no Origin header) are allowed, which is the path agents use. Full reference: docs.ophis.fi/intent-api.

Related MCP server: Theagora MCP Server

Agents and SDK

Ophis is built to be traded by autonomous agents, not just people. Pick your integration depth, all of it non-custodial and keyless:

MCP server (recommended)

Point any MCP client (Claude, Cursor, a custom agent) at the hosted Model Context Protocol server:

https://mcp.ophis.fi/mcp

It speaks Streamable-HTTP MCP and exposes six tools: parse_intent, get_quote, build_order, submit_order, lookup_tier, and list_chains. The server holds no keys and never signs. build_order returns a bounded, ready-to-sign EIP-712 order with the receiver pinned to the owner; the agent signs locally with its own key and submits. (A bare request without an Accept: text/event-stream header returns HTTP 406, that is the transport negotiating, not an outage.)

@ophis/sdk

For agents that build and sign CoW orders directly:

npm install @ophis/sdk

The SDK encodes four fork details that fail silently if you guess them:

• getOphisOrderbookUrl(chainId) picks the right host. Optimism self-hosts its orderbook (not api.cow.fi); the wrong host bypasses the Ophis solver and zeroes the fee.

• getOphisOrderDomain(chainId) gives the EIP-712 domain with the correct verifyingContract. The OP settlement is non-canonical, so the cow-sdk default is rejected on-chain.

• buildOphisAppDataPartnerFee(chainId) builds the exact CIP-75 volume-fee fragment { volumeBps, recipient }, not the price-improvement shape.

• assertReceiverIsOwner(owner, receiver) pins the order receiver. An unpinned receiver is the number one drain vector for an automated signer.

Discovery and the trust boundary

Ophis publishes machine-readable manifests for agent discovery under https://ophis.fi/.well-known/: mcp.json, ai-plugin.json, agent-skills/, and api-catalog (RFC 9727), plus the root-served auth.md, llms.txt, and openapi.json.

These off-chain helpers make the safe path the easy path, but they are guards, not an authorization boundary: a prompt-injected agent can ignore them. For an agent that signs without a human in the loop, enforce policy where the agent cannot reach it: funds in a Safe smart account, a deterministic policy gate (allowlisted tokens, pinned receiver and appData, an oracle-bounded limit price, spend caps), a guardian key, and the same policy checked again at orderbook ingestion. Full guide: docs.ophis.fi/ai-agents.

Status

Ophis settles across two kinds of chains.

Ophis-operated (self-hosted orderbook, solver, and settlement; Ophis keeps the full fee):

CoW-hosted (orders route through CoW Protocol's settlement and solver network, with the partner fee disbursed by CoW): Ethereum, Base, Arbitrum, Polygon, BNB, Gnosis, Avalanche, Linea, and the other CoW-supported chains, all live.

The two have different settlement contracts and orderbook hosts, so resolve them per chain via @ophis/sdk or the MCP list_chains tool rather than assuming. Full live status: docs.ophis.fi/status. Cross-chain destinations (Solana, Bitcoin) are surfaced via NEAR Intents. Canonical contract addresses and the disclosure policy live in SECURITY.md.

Architecture

Upstream subtrees are vendored as-is; Ophis changes are catalogued in apps/frontend/.ophis-divergences.md and apps/backend/.ophis-divergences.md so git subtree pull stays tractable.

Repo map

ophis/
├── apps/
│   ├── frontend/        cowswap fork: swap UI + explorer + landing site
│   ├── backend/         cowprotocol/services fork (Rust)
│   ├── rebate-indexer/  tier + WETH rebate API, Safe batch proposer
│   ├── docs-ophis/      Docusaurus docs portal
│   └── mcp-server/      agent-facing MCP Worker (mcp.ophis.fi)
├── contracts/           GPv2 settlement contracts (+ per-network deployments)
├── packages/sdk/        @ophis/sdk
├── functions/           Cloudflare Pages Functions (intent API, bungee, middleware)
├── infra/               per-chain runtime stacks + rpc + cloudflare config
├── scripts/             repo utility scripts
└── docs/                specs, plans, audits, operations runbooks

Build

Root workspace (pnpm 9, Node 20.19+ or 22.12+, turborepo):

pnpm install      # all root-workspace deps
pnpm build        # builds members with a build step (currently @ophis/sdk)
pnpm typecheck    # typechecks every member
pnpm test         # runs the unit suites

Only packages/sdk has a build step today. apps/rebate-indexer, apps/mcp-server, and infra/rpc run directly (no build script) and are validated by pnpm typecheck and pnpm test. The Rust backend (apps/backend) is a Cargo workspace, not a pnpm package, so build and test it with Cargo:

cd apps/backend && cargo build && cargo test

apps/frontend and apps/docs-ophis are self-contained pnpm workspaces with their own lockfiles, deliberately excluded from the root. Build them from inside their own directory (see each app's README):

cd apps/frontend   && pnpm install --frozen-lockfile && pnpm run build:cowswap
cd apps/docs-ophis && pnpm install --frozen-lockfile && pnpm run build

The contracts use Foundry (forge build); forge-std is a git submodule, so run git submodule update --init first.

Deploy

Every surface deploys independently from main:

• Swap app and Explorer cloudflare-deploy.yml: two sequential Cloudflare Pages deploys (swap.ophis.fi / ophis.fi, then explorer.ophis.fi).

• Landing landing-deploy.yml: path-filtered build with a Playwright and Lighthouse budget gate, to Cloudflare Pages.

• Docs docs-deploy.yml: the Docusaurus site to its own Cloudflare Pages project.

• MCP server mcp-deploy.yml: to Cloudflare Workers (custom domain mcp.ophis.fi) with a least-privilege Workers token.

• Rebate indexer rebate-indexer-deploy.yml: to self-hosted infrastructure over a private network.

• OP backend: the live Optimism orderbook, autopilot, driver, and solvers run on self-hosted infrastructure via docker compose (defined under infra/optimism-mainnet/), exposed through a Cloudflare tunnel. Not a GitHub workflow.

Quality gates: ci.yml (lint, typecheck, tests), codeql.yml, security.yml (dependency and supply-chain scans), and echidna.yml (contract fuzzing). sdk-release.yml publishes @ophis/sdk to npm.

Fees and rebates

Ophis charges the CoW Protocol CIP-75 volume policy: a flat 0.10% (10 bps) of trade volume, reduced to 0.01% (1 bp) on same-chain stablecoin pairs, and nothing on surplus. On Optimism the stack settles on its own infrastructure and keeps the full fee; on CoW-hosted chains the partner share is disbursed weekly in WETH.

Part of the fee flows back to traders:

• Volume-tier rebates. Each month a share of collected WETH fees is paid back, split across active wallets by 30-day volume and tier (Bronze through Platinum). The rebate indexer computes shares and a Safe batch proposer pays out.

• Referrals. Mint a code, share https://swap.ophis.fi/?ref=YOURCODE, and earn 8% of the net fee Ophis keeps on trades your referrals route, paid monthly in WETH.

Full numbers and the tier ladder: docs.ophis.fi/fees and docs.ophis.fi/affiliate.

Security

See SECURITY.md for the disclosure policy, canonical contract addresses, the partner-fee recipient and governance model, in-scope components, and audit history.

License

GPL-3.0, inherited from upstream CoW Protocol.