Lambda Lang + ASAP Protocol Integration

March 11, 2026 · View on GitHub

This document describes how Lambda Lang is used within ASAP Protocol for semantic compression of JSON-RPC 2.0 payloads.

Overview

ComponentPurpose
ASAP ProtocolTransport layer — JSON-RPC 2.0 over HTTP/WebSocket, task orchestration
Lambda LangCompression layer — semantic atom substitution for payload size reduction

Together they provide compressed agent-to-agent communication:

┌─────────────────────────────────────────┐
│  Lambda Lang (semantic compression)     │  ← "How to compress"
│  §Jrpc§ §Mthd§ §Treq§ §Hb§              │
├─────────────────────────────────────────┤
│  ASAP Protocol (transport layer)        │  ← "How to communicate"
│  JSON-RPC 2.0 / HTTP / WebSocket        │
└─────────────────────────────────────────┘

Content-Type Negotiation

ASAP uses standard HTTP content negotiation to enable Lambda compression. The mechanism is fully opt-in — when not requested, everything stays JSON.

Request flow

Agent A                                          Agent B
  │                                                │
  │──── POST /asap ─────────────────────────────▶  │
  │     Accept: application/vnd.asap+lambda        │
  │                                                │
  │  ◀──── 200 OK ───────────────────────────────  │
  │        Content-Type: application/vnd.asap+lambda
  │        Body: λ1:{§Jrpc§:§V2§, §Mthd§:§Am§, …}  │
  │                                                │

Content-Type

application/vnd.asap+lambda

Version prefix

All encoded payloads start with λ1: for forward compatibility. Future codec versions can use λ2:, etc.

Fallback behavior

  • If the server cannot encode with Lambda, it falls back to application/json silently
  • Error responses are always returned as JSON regardless of Accept header
  • Wildcard Accept: */* does NOT trigger Lambda encoding (conservative negotiation)

Atom Mapping

The codec substitutes common JSON-RPC and ASAP keys with short Lambda atoms wrapped in §…§ delimiters (chosen because § cannot appear in valid JSON).

JSON-RPC standard keys

JSON keyLambda atom
"jsonrpc"§Jrpc§
"method"§Mthd§
"params"§Prms§
"result"§Rslt§
"error"§Er§
"id"§Id§
"code"§Cd§
"message"§Msg§
"data"§Dt§

ASAP envelope keys

JSON keyLambda atom
"envelope"§Env§
"sender"§Snd§
"recipient"§Rcp§
"payload"§Pld§
"payload_type"§Pt§
"task_id"§Ta§
"status"§St§
"trace_id"§Tr§
"timestamp"§Ts§
"version"§Vr§

ASAP values

JSON valueLambda atom
"asap.message"§Am§
"2.0"§V2§
"task.request"§Treq§
"task.response"§Tres§
"task.status"§Tst§
"heartbeat"§Hb§
"success"§Ok§
"pending"§Pn§
"running"§Rn§
"completed"§Cp§
"failed"§Fl§
"cancelled"§Cx§

Total: 35 atom mappings covering the full JSON-RPC + ASAP envelope vocabulary.

Compression Example

Original JSON (235 chars)

{"jsonrpc":"2.0","method":"asap.message","id":"abc-123","params":{"envelope":{"sender":"agent-a","recipient":"agent-b","payload_type":"task.request","status":"pending","trace_id":"tr-456"}}}

Lambda-encoded (170 chars)

λ1:{§Jrpc§:§V2§,§Mthd§:§Am§,§Id§:"abc-123",§Prms§:{§Env§:{§Snd§:"agent-a",§Rcp§:"agent-b",§Pt§:§Treq§,§St§:§Pn§,§Tr§:"tr-456"}}}

Compression ratio: ~28% reduction on this typical ASAP envelope. Savings increase with larger payloads containing more substitutable keys.

Implementation Details

Codec architecture

  • Self-contained: No dependency on the lambda-lang Python package — all atom mappings are inline
  • Single-pass regex: Pre-compiled re.compile() pattern for C-level substitution speed (no Python for loop)
  • String-based API: encode(json_str) → str and decode(encoded) → str — accepts pre-serialized JSON to leverage Pydantic v2's Rust core (model_dump_json())
  • 100% fidelity: decode(encode(s)) == s for any valid JSON string

Event loop safety

Both server-side encoding and client-side decoding are offloaded via asyncio.to_thread() to prevent blocking FastAPI's event loop on large payloads.

Source code

Resources

Integration designed by @adriannoes — ASAP Protocol maintainer