{"version":"2.1.292","anchor":"new-claude-code-artifact-versions-env-var-added-to-the-passt","canonical_anchor":"new-claude-code-artifact-versions-env-var-added-to-the-passt","heading":"Artifact tool can read past versions and look in the artifact viewer","tier":"notice","area":"Artifacts","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.292\/e\/new-claude-code-artifact-versions-env-var-added-to-the-passt","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.292","markdown":"### Artifact tool can read past versions and look in the artifact viewer\n\nThe artifact tool gains reads of earlier artifact versions, new `page_versions` and `emulatorPreview` kinds, and a new `CLAUDE_CODE_ARTIFACT_VERSIONS` variable\n\n**Unclear.** What the variable does, and whether these lists pass it through or strip it out, is not clear.\n\n**What**\n\nArtifacts are pages or files Claude builds and shows in an artifact viewer. The tool Claude uses to work with them gains two new abilities.\n\n- Past-version reads: the artifact read function takes a new `pastVer` argument, which is passed to the boot read and adds `&ver=` to the frame request. When it is set, the local-replica fast path (a shortcut that reads a local copy) is skipped. Before, there was no version parameter and the replica was used whenever the artifact was a cowritten type and no file was read.\n\n- New errors for version reads: an HTTP 400 maps to `boot_unknown_ver`, with a message saying the server refused that version id and that listing the artifact's versions shows which ones are kept. A response for a different version than the one asked for maps to `boot_past_ver_ignored`.\n\n- A new `_e` path reads frame content through a content-fetch helper when the artifact data qualifies for it.\n\n- `page_versions`: a new artifact kind with its own result handler.\n\n- `emulatorPreview`: a new artifact kind. Its results read \"Looked at \u2026 in the artifact viewer\", \"Stopped looking at \u2026\" or \"Could not look at \u2026\". When a mode check returns emulator, the tool prompt and preview wording say \"a look in the artifact viewer\" instead of \"local preview\", and a different prompt paragraph is used. Before, only \"local preview\" and \"Previewed\" wording existed.\n\n- `CLAUDE_CODE_ARTIFACT_VERSIONS`: a new environment variable (a setting passed in from outside the program), absent from the previous build. It is added to three lists of variable names next to `CLAUDE_CODE_ARTIFACT_SHARE`; these lists appear to cover variables forwarded to child or host processes. Nothing that reads it was traced, so its effect is unknown, though it may switch version reads on.\n\n**Why**\n\nClaude may be able to look at earlier versions of an artifact rather than only the current one, and to view artifacts in the artifact viewer itself. Because the controlling variable's reader was not found, these pieces may not be active yet.\n\n- Area: Artifacts\n- Names: `CLAUDE_CODE_ARTIFACT_VERSIONS`\n- Tier: You'll notice\n- Useful: 4\/5\n- Signal: 4\/5\n- Scope: individual\n- Heads-up: no"}