Cognition Devin CLI Leaks Five-Tier Silicon Model Family

Reverse-engineering Cognition's latest Devin CLI build has uncovered references to a previously unknown model family called Silicon, structured across five distinct performance tiers. The identifiers surfaced in a November 7, 2026 build but were completely absent from an October 30 release, pointing to a rapid integration timeline. While X users have linked the discovery to Anthropic through codename patterns, neither lab has confirmed the model's origin or specifications.

The Five-Tier Architecture

Cognition's Devin CLI build 3000.12.28, published November 7 on npm, contains five Silicon model identifiers: silicon-low, silicon-medium, silicon-high, silicon-xhigh, and silicon-max. These identifiers appear in the binary's text strings directly after Obsidian 3 entries and follow the same naming convention Devin uses for Claude Opus 5.5 and Claude Haiku 5.5 models. The October 30 build (3000.11.234) contains zero Silicon references, indicating the model family was added within an eight-day window.

The tier names match Anthropic's documented effort levels exactly, which the company uses to control computational intensity across inference requests. However, matching naming conventions alone do not confirm attribution. The identifiers themselves carry no explicit lab signature beyond their structural similarity to existing Claude model patterns in Devin's harness.

The Codename Connection

X user @chetaslua posted November 7 that reverse-engineering Devin CLI build 3000.12.17 revealed a mapping between the codename claude-donut-eap and silicon-high. The same analysis reportedly linked claude-onigiri-eap to obsidian-3-high. Users interpret the claude- prefix as a pointer to Anthropic, though this attribution remains speculation. The build number referenced in the X posts (3000.12.17) does not appear on npm's public registry, preventing independent verification of the donut-to-Silicon mapping.

The codename first surfaced in a November 7 post from @abhinavflac, who noted it appeared alongside identifiers for Opus 5.5, Mythos 5.1, and Haiku 5.5 in the Devin CLI. No -eap suffix identifiers appear in the November 7 build available for download, and the string claude-donut-eap is absent from the binary text we inspected.

Obsidian 3 and Prior Leaks

The Silicon identifiers sit adjacent to Obsidian 3 entries in Devin's model list. Obsidian 3 previously appeared in Cognition's archived FrontierCode benchmark data on October 28, scoring 46.8 percent compared to Claude Opus 5.5's 45.5 percent before the entry was removed. That benchmark file assigned Obsidian 3 a chart color used for Muse Wonder 1.0, not the color coding applied to Claude models, further muddying attribution.

Both Silicon and Obsidian 3 remain unnamed in any official Anthropic documentation or release notes. Third-party harnesses like Devin can surface model identifiers before labs announce them publicly, as evidenced by the Obsidian 3 benchmark leak. This pattern suggests Cognition may be testing unreleased models in its AI coding assistant before general availability.

Expected Release Timeline

No official release date exists for the Silicon model family. Anthropic has not acknowledged the model's existence, and Cognition has not described it on any public-facing page. Based solely on the build timeline, integration occurred between October 30 and November 7, 2026, but this reflects internal testing, not market readiness. Rumored to release on an unspecified 2026 timeline, the model's capabilities, training methodology, and target use cases remain entirely unknown outside of the tier structure visible in the CLI strings.

What This Means

The discovery highlights how third-party AI harnesses serve as unintentional disclosure surfaces for unreleased models. Cognition's Devin CLI now references a five-tier model family with no public documentation, benchmark results, or confirmed builder. The naming patterns and tier structure suggest a reasoning-focused model designed for variable computational effort, aligning with current trends in agentic AI systems. Until Anthropic or Cognition issues a statement, Silicon remains a ghost in the build logs: present in code, absent from any roadmap, and expected to release on an unspecified 2026 timeline.