lapsh 0.4.6

Lean API Platform -- Token-efficient API specs for AI agents

LAP -- Lean API Platform

Compile API specs into token-efficient contracts for LLM agents.

Website · Registry · Benchmarks · Docs

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LLMs waste thousands of tokens parsing bloated API specs. Stripe's OpenAPI spec is 1M+ tokens — mostly YAML scaffolding, nested wrappers, and repeated schemas. LAP compiles any API spec into a typed, flat format that preserves every endpoint, parameter, and constraint in a fraction of the tokens.

Not minification — a purpose-built compiler with its own grammar.

Proven in 500 blind runs across 50 APIs

LAP Lean scored 0.851 (vs 0.825 raw) while using 35% less cost and 29% less time -- same accuracy, far fewer tokens.

Full benchmark report (500 runs, 50 specs, 5 formats) · Benchmark methodology and data

Install

# Try without installing
npx @lap-platform/lapsh compile api.yaml

# Or install
pip install lapsh
lapsh compile api.yaml -o api.lap

What You Get

• 🗜️ 5.2× median compression on OpenAPI, up to 39.6× on large specs — 35% cheaper, 29% faster (benchmarks)
• 📐 Typed contracts — enum(a|b|c), str(uuid), int=10 prevent agent hallucination
• 🔌 6 input formats — OpenAPI, GraphQL, AsyncAPI, Protobuf, Postman, Smithy
• 🎯 Zero information loss — every endpoint, param, and type constraint preserved
• 🔁 Round-trip — convert back to OpenAPI with lapsh convert
• 📦 Registry — browse and install pre-compiled specs at lap.sh
• 🤖 Skill generation — lapsh skill creates agent-ready skills from any spec
• 🔗 Integrations — LangChain, CrewAI, OpenAI function calling, MCP

How It Works

Five compression stages, each targeting a different source of token waste:

Stage	What it does	Savings
Structural removal	Strip YAML scaffolding — paths:, requestBody:, schema: wrappers vanish	~30%
Directive grammar	@directives replace nested structures with flat, single-line declarations	~25%
Type compression	type: string, format: uuid → str(uuid)	~10%
Redundancy elimination	Shared fields extracted once via @common_fields and @type	~20%
Lean mode	Strip descriptions — LLMs infer meaning from well-named parameters	~15%

Benchmarks

162 specs · 5,228 endpoints · 4.37M → 423K tokens

Format	Specs	Median	Best
OpenAPI	30	5.2×	39.6×
Postman	36	4.1×	24.9×
Protobuf	35	1.5×	60.1×
AsyncAPI	31	1.4×	39.1×
GraphQL	30	1.3×	40.9×

Verbose formats compress most — they carry the most structural overhead. Already-concise formats like GraphQL still benefit from type deduplication.

The Ecosystem

LAP is more than a compiler:

Component	What	Command
Compiler	Any spec → .lap	lapsh compile api.yaml
Registry	Browse & install pre-compiled specs	lapsh skill-install stripe
Skill Generator	Create agent-ready skills from any spec	lapsh skill api.yaml --install
API Differ	Detect breaking API changes	lapsh diff old.lap new.lap
Round-trip	Convert LAP back to OpenAPI	lapsh convert api.lap -f openapi
Publish	Share specs to the registry	lapsh publish api.yaml --provider acme

Supported Formats

lapsh compile  api.yaml           # OpenAPI 3.x / Swagger
lapsh compile  schema.graphql     # GraphQL SDL
lapsh compile  events.yaml        # AsyncAPI
lapsh compile  service.proto      # Protobuf / gRPC
lapsh compile  collection.json    # Postman v2.1
lapsh compile  model.smithy       # AWS Smithy

Format is auto-detected. Override with -f openapi|graphql|asyncapi|protobuf|postman|smithy.

Top Compressions

Integrations

# LangChain
from lap.integrations import LAPLoader
docs = LAPLoader("stripe.lap").load()

# OpenAI function calling
from lap.integrations import to_openai_functions
functions = to_openai_functions("stripe.lap")

Also: CrewAI tool, MCP server and compression proxy. See integration docs.

FAQ

How is this different from OpenAPI?

LAP doesn't replace OpenAPI — it compiles FROM it. Like TypeScript → JavaScript: you keep your OpenAPI specs, your existing tooling, everything. LAP adds a compilation step for the LLM runtime.

How is this different from MCP?

MCP defines how agents discover and invoke tools (the plumbing). LAP compresses the documentation those tools expose (the payload). They're complementary — LAP can compress MCP tool schemas.

Why not just minify the JSON?

Minification removes whitespace — that's ~10% savings. LAP performs semantic compression: flattening nested structures, deduplicating schemas, compressing type declarations, and stripping structural overhead. That's 5-40× savings. Different class of tool.

What about prompt caching?

Use both. Compress with LAP first, then cache the compressed version. LAP reduces the first-call cost and frees context window space. Caching reduces repeated-call cost. They stack.

Will LLMs understand this format?

Yes. LAP uses conventions LLMs already know — @directive syntax, {name: type} notation, HTTP methods and paths. In blind tests, agents produce identical correct output from LAP and raw OpenAPI. The typed contracts actually reduce hallucination.

What if token costs keep dropping?

Cost is the least important argument. The core value is typed contracts: enum(succeeded|pending|failed) prevents hallucinated values regardless of token price. Plus: formal grammar (parseable by code, not just LLMs), schema diffing, and faster inference from fewer input tokens.

Contributing

See CONTRIBUTING.md. The test suite has 545 tests across 177 example specs in 6 formats.

git clone https://github.com/Lap-Platform/lap.git
cd lap
pip install -e ".[dev]"
pytest

License

Apache 2.0 — See NOTICE for attribution.

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lap.sh · Built by the LAP team