Canonical support matrix

What “supported” means in Once

Installation boundary: default MCP exposes eight developer assessment/setup tools and does not automatically protect sibling GitHub, Adobe or other connectors. Registered actions are opt-in; the proxy protects only reviewed/configured upstream boundaries. The default helper supports Node 20+; local SQLite proxy/actions require 24.15+. The original durable ledger is execution authority: replacement, reset or rollback may permit an effect again, even at the same path. UNKNOWN never grants permission to redispatch. Authoritative compatibility and continuity matrix.

Once uses several different integration layers. This page separates them so “supported” is not mistaken for a universal runtime guarantee.

Key: “Example” means public integration guidance exists. “Hostile-retry evidence” means a reproducible failure lab exists. “Discovery” means Once can inspect or classify the tool surface. “Protected runtime path” means the Once execution boundary is actually on the path of the side effect.
Framework / hostIntegration exampleHostile-retry evidenceDiscovery / classificationProtected runtime path
OpenAI AgentsYesNo dedicated hostile-retry lab claimed hereYes — FunctionTool structural wrapping / Connect pathYes, when tools are routed through the supported Once local or hosted execution boundary
Vercel AI SDKYesNo dedicated hostile-retry lab claimed hereYes — documented discovery supportYes, when the consequential tool is routed through a supported Once boundary
LangChain / LangGraphYesYes — LangGraph hard-process-death / fresh-process recovery labYes — documented discovery supportYes, for the tested / integrated path
CrewAIYesYes — native BaseTool hostile-retry labRuntime discovery adapter not claimed as equivalent to protectionYes, for the tested / integrated path
Microsoft Agent FrameworkYesNo dedicated hostile-retry lab claimed hereFramework integration documentedYes, when routed through a supported Once boundary
AgnoEvidence-focused exampleYes — retries after successful tool execution followed by model HTTP 500Do not infer discovery-adapter support from the hostile-retry labYes, for the released SDK path used by the lab
Google ADKControlled parallel-replay labPinned released/base/proposed-fix comparison; forced replay, UNKNOWN and same-machine boundary concurrencyRuntime discovery is separate from protectionTested host-owned boundary only; no whole-framework recovery or production-provider qualification
Claude CodeMCP / plugin setupNot a framework hostile-retry benchmarkMCP-assisted assessment and setupMCP installation alone is not protection; runtime must sit on the side-effect path
CursorProject-scoped MCP setupNot a framework hostile-retry benchmarkMCP-assisted assessment and setupMCP installation alone is not protection
CodexPlugin / marketplace setupNot a framework hostile-retry benchmarkPlugin teaches routing / assessment and exposes MCPPlugin installation alone is not the runtime safety boundary

Current automatic local protection boundary

@once-agent/sdk/connect can classify supported local tool descriptors as BYPASS, PROTECT, or fail-closed UNKNOWN, resolve trusted logical identity, bind effect-bearing data, and connect supported same-machine tool registries. Automatic protected local execution uses durable same-machine SQLite on Node.js 24.15+.

This is not a multi-host or universal exactly-once guarantee. A framework being listed here does not mean every tool, provider, transport, HTTP method, or deployment topology is automatically protected.

Evidence boundary

Dedicated framework evidence includes the LangGraph, CrewAI and Agno hostile-retry labs and the Google ADK controlled replay comparison. These have different failure models and limits; none qualifies every deployment or provider. The controlled booking lifecycle reference demonstrates a mock create/modify/cancel contract, not a production booking adapter.

Project identity · Provider reconciliation matrix · Research · Security policy and private reporting · GitHub