ACP scrapped, sealbridge published on npm for cross-owner agent tasks

Sealbridge is the successor to ACP, a zero-trust framework the same developer previously released as open source for delegating work to others' Claude Code or Codex without handing over API keys. The rewrite changed both the design and the distribution model: ACP required cloning a Git repository, while sealbridge is an npm package installed with a single command, which the developer says dramatically shortens the distance to getting someone else to try it. The way relationships start also changed—from cumbersome key and connection-info exchange, which the developer identifies as the biggest drop-off point, to simply passing an invite link or token. The approval model is deliberately conservative: agents automatically accept only read-only work from connected partners, while write or command-execution tasks need the owner's approval, and running a worker on one's own PC requires an explicit --allow-local-pc flag (fail-closed). Every request, acceptance, start, delivery, verification, and completion event is signed and chained, so tampering with one side's log can be detected by comparing it with the other; when no trust anchor is present, the tool honestly reports that truncation detection is not guaranteed. As a real-world test, the developer delegated readability reviews of text to an agent owned by someone else (Grok Bot). After several days of isolating unstable relay connections caused by a proxy environment, a delegated task reached SETTLED in about 12 seconds, the deliverable was returned, and the audit log verified as VALID with no retries—showing that asking another person's agent for work and receiving it with evidence can be a routine operation rather than a demo.