What effector is, why it exists, and how it fits into the AI agent landscape.
Overview
Effector is the standard toolkit for typed AI agent tool interoperability. It adds a typed interface layer to AI agent tools โ 40 standard capability types, static composition checking, and cross-runtime compilation from a single sidecar manifest.
AI agent capabilities are in the pre-TypeScript era. effector-types is the lib.d.ts for Effectors โ the standard library of capability types grounded in real-world usage from 13,000+ analyzed tools.
The Problem
Every AI agent tool has an implicit interface: it takes something, produces something, and needs something from the environment. But today, these interfaces are invisible. The consequences:
- Composition by prayer. You chain two MCP tools and discover at runtime that they're incompatible โ after burning tokens, time, and API calls.
- Runtime lock-in. MCP tools only work in MCP. LangChain tools only work in Python. Your capability definitions are trapped in one ecosystem.
- Discovery by keyword. Finding a tool that produces
ReviewReportfromCodeDiffrequires reading READMEs, not querying a type catalog. - Implicit security. Whether a tool accesses the network or filesystem is buried in implementation, not declared in metadata.
The Solution
Effector adds a typed interface layer to AI agent tools. It's a sidecar manifest โ your tool keeps running exactly as before. Drop an effector.toml next to your tool:
Now your tool has:
- Type-safe interfaces โ input/output/context from 40 standard capability types
- Static composition checking โ verify tool chains before execution
- Cross-runtime portability โ compile to MCP, OpenAI, LangChain, or JSON
- Security auditing โ declared permissions vs actual behavior
How It Compares
| Feature | Raw MCP | LangChain | CrewAI | effector |
|---|---|---|---|---|
| Type safety | None | None | None | 40 standard types |
| Composition | Manual | Runtime only | Rigid roles | Static verification |
| Cross-runtime | MCP only | Python only | Python only | MCP, OpenAI, LangChain, JSON IR |
| Discovery | By name | By name | By name | By input/output type |
| Dependencies | Varies | Heavy | Heavy | Zero |
| Permission model | None | None | None | Declared + audited |
| Existing tools | N/A | Rewrite | Rewrite | Unchanged (sidecar) |
The Toolchain
effector is a cohesive ecosystem of focused tools, each doing one thing well:
| Tool | What it does |
|---|---|
@effectorhq/core | Shared kernel โ TOML parser, type checker, schema validator, compiler |
create-effector | Scaffold new capabilities in seconds with interactive prompts |
@effectorhq/skill-lint | Validate SKILL.md structure, frontmatter, and section coverage |
@effectorhq/audit | Security analysis โ permission mismatches, undeclared access, trust scores |
@effectorhq/compose | Static pipeline builder โ verify type compatibility between tools |
@effectorhq/graph | Interactive dependency graph (D3 force layout, spectrum, dashboard) |
@effectorhq/skill-eval | Quality scoring (0-100) across 10 weighted dimensions |
effector-studio | Visual editor for building manifests with compile target preview |
Architecture
effector.toml + SKILL.md (your capability definition)
โ
โโโ validate โ schema validator + type checker
โโโ lint โ SKILL.md structure checks
โโโ audit โ permission + trust analysis
โโโ compose โ type-based pipeline verification
โโโ compile โ MCP / OpenAI / LangChain / JSON IR
โโโ graph โ dependency visualization
All tools share @effectorhq/core as a kernel. Every module uses only Node.js built-ins โ zero external dependencies, zero supply chain risk.
Next Steps
- Installation โ get started in 30 seconds
- Your First Manifest โ build an
effector.tomlfrom scratch - Type System โ understand the 40-type catalog
- Playground โ validate manifests live in your browser