orcha-sdk

The developer SDK + emerge CLI for Metaorcha — an orchestration runtime that plans, routes, and executes one goal across agents speaking MCP, A2A, and COMPUTER_USE (ACP is accepted as an A2A-routed alias).

Register an agent in three lines:

import emerge

@emerge.agent(name="My Agent", description="What I do")
def handle(task: str) -> str:
    return f"handled: {task}"

Then serve it:

orcha-sdk run          # serve locally + register against the local registry

Install

No clone, no venv setup — just run it:

uvx orcha-sdk init my-agent

Or install it into a project:

pip install orcha-sdk

(Import name is emerge; distribution name is orcha-sdk.)

CLI

orcha-sdk run --no-register serves without registering. Set ORCHA_REGISTRY_URL and ORCHA_PAT to point at and authenticate against a non-local registry.

Verifying run attestations

When the runtime runs with RUN_ATTESTATION_ENABLED, every completed run is sealed into a signed orcha.run-attestation/v1 envelope (RFC 0003). Anyone holding the envelope JSON can verify it for free, fully offline:

uvx --from orcha-sdk orcha verify envelope.json          # no clone
uvx --from orcha-sdk orcha verify envelope.json --json
orcha-sdk verify envelope.json                           # after pip/uv install
cat envelope.json | orcha-sdk verify -

Verification recomputes the schema check, the step hash chain (steps_root), and the Ed25519 signature against the envelope's embedded signer.public_key_b64 — no network calls, no registry, no DID resolution.

Exit codes: 0 envelope is valid · 1 envelope is invalid (schema, chain, or signature check failed) · 2 usage/input error (unreadable file, malformed JSON, unsupported option).

valid=True means the signature and commitments are sound. It does not mean the run was accepted. A signed verdicts[] entry with result: fail still verifies: the envelope is honest about the failure. Settlement refusal is gate policy (verdict_fail on the settle audit row), never this exit code.

How it works

The decorator records your handler and declared skills. orcha-sdk run serves an A2A-compatible HTTP endpoint (/health, /.well-known/agent.json, JSON-RPC message/send / tasks/get) using only the standard library, and uploads a generated emerge.yaml to the registry. The runtime's planner can then discover and orchestrate your agent alongside agents that speak other protocols.

Apache 2.0 runtime, MIT SDK. See the main repo.