Introduction
Splice is infrastructure for composing capabilities into autonomous agents. It gives an agent a safe way to discover, install, verify and run reusable capabilities — and to reach real data providers through them — without every agent rebuilding the same integrations.
Splice is the splice CLI, the TypeScript SDK (@spliceloom/sdk), the MCP server, the registry and the runtime. Packages are published under the @spliceloom npm scope, and the website lives at spliceloom.com.
The building blocks
| Concept | What it is | Read more |
|---|---|---|
| Skill | A versioned package of tools (input/output schemas, code, docs) with declared permissions. | Skills |
| Capability | Something a skill may do: touch a project path, reach a host, read a variable, or call a host capability such as web.search. | Host capabilities |
| Provider | A real external service the host uses to answer capabilities: Alchemy, Blockscout, CoinGecko, GitHub, OpenRouter, Tavily, … | Providers reference |
| Registry | Public package registry: namespaces, immutable versions, SHA-256 integrity and provenance. | Public registry |
| Runtime | Runs each tool call in its own restricted Node.js process. | Runtime |
| Agent | Your agent or application — Claude Code, Cursor, a custom agent — using Splice through the CLI, SDK or MCP. | MCP |
How it fits together
agent (MCP client · SDK · CLI)
└─ skill tool ── verified package, sandboxed process
└─ ctx.capability("onchain.balance", …) ── declared + granted permission
└─ host broker → provider router → provider (e.g. Alchemy, chain id verified)
└─ result: LIVE / CACHED / UNAVAILABLE / ERROR, with provenance- Packages are verified (SHA-256, size, manifest, provenance) before a file is written.
- Everything a package may touch is declared and needs consent; the grant is pinned in
splice.lock. - Data results always state their source, time, chain and block — and never contain invented values: when no provider can answer, the result says
UNAVAILABLE.
What Splice is not
- Not an agent or a model. Bring your own; Splice supplies capabilities.
- Not a blockchain. Robinhood Chain and other networks are data sources Splice reads from (see Robinhood Chain).
- Not a hosted execution service. Skills run on your machine or server, in the Splice sandbox.
Next
- Install the CLI, then follow the quickstart.
- Read the security model before running third-party skills.