Skip to content

FAQ

No. The signature and the signer’s public key travel inside the capsule. Verification is a local computation — it works offline, from a file on disk, with no registry, no key server, and no network request.

No. There is no ledger, no token, no consensus. A capsule is a compressed, optionally encrypted, optionally signed blob plus plain ECDSA verification.

Four pieces, all in one repository: @altweb/core (the headless engine), @altweb/cli (compile / decode / verify / keygen), @altweb/mcp (the altweb-context loader), and @altweb/editor (the Novel-based visual editor, under active development). That is the complete list — there is no browser extension and no hosted service.

Dual-licensed. The open-source license is AGPL-3.0-or-later: free to use, study, modify, and share — with the copyleft obligation that if you modify ALTWEB and either distribute it or run it as a network service (for example, hosting the altweb-context loader for others), you release your modified source under the same license. For closed-source or hosted-without-sharing use, there is a separate commercial license by agreement — see COMMERCIAL.md in the repository. Bundled third-party components keep their own permissive licenses; see Credits.

If a capsule is signed, is it safe to load?

Section titled “If a capsule is signed, is it safe to load?”

No — signed means attributable and intact, not safe. A signature tells you who wrote the content and that it has not changed. Whether you take instructions from that signer is your decision, expressed in the trust file. See the security model.

The identity is unrecoverable — there is no reset, because there is no server. Pick a new passphrase, publish the new fingerprint, and ask the people who trust you to update their trust files. (The flip side: there is also no account to compromise centrally.)

Can two people share one signing identity?

Section titled “Can two people share one signing identity?”

Technically yes — anyone who knows the passphrase derives the same keypair. That is a feature for teams and a warning for individuals: the passphrase is the identity, so share it only if you mean “we sign as one”.

Why does an encrypted capsule show “signed but unverifiable”?

Section titled “Why does an encrypted capsule show “signed but unverifiable”?”

The signature covers the decrypted payload. Without the password, the verifier cannot recompute what was signed, so it honestly reports the tri-state instead of guessing. Supply the password and verification completes.

No. A capsule verifies forever, and verification says nothing about freshness. If you need “latest version” semantics, that is a distribution concern — publish capsules at a stable URL and re-fetch.

Does the standalone HTML file load anything from the network?

Section titled “Does the standalone HTML file load anything from the network?”

No. The renderer and sanitizer (DOMPurify) are inlined, and the file carries a strict Content-Security-Policy (default-src 'none'). It works from disk, in a browser, with the network cable unplugged.

Because that is what agent context already is: CLAUDE.md, personas, skills, notes. ALTWEB adds provenance to the format teams already use, rather than inventing a new one.