Track Claude Sonnet 5 model version

[a5c-ai]

Summary

Anthropic's current Claude model documentation lists Claude Sonnet 5 as a current model, but the Atlas graph appears to only mention Sonnet 5 in downstream agent-version notes (upstream-current-2026-07-01/02) and does not have a model:claude-sonnet-5@current ModelVersion node.

Evidence

Official docs reviewed on 2026-07-04:

• Anthropic models overview: https://platform.claude.com/docs/en/about-claude/models/overview.md
• Anthropic pricing: https://platform.claude.com/docs/en/about-claude/pricing.md
• Anthropic model deprecations: https://platform.claude.com/docs/en/about-claude/model-deprecations.md

Key official doc details:

• Exact model ID / Claude API ID: claude-sonnet-5
• Claude API alias: claude-sonnet-5
• AWS Bedrock ID: anthropic.claude-sonnet-5
• Google Cloud / Vertex ID: claude-sonnet-5
• Provider: Anthropic
• API family: Anthropic Messages API; also available through Bedrock/Vertex/Claude Platform on AWS/Microsoft Foundry according to the model overview's current-model availability note
• Context window: 1M tokens
• Max synchronous Messages API output: 128k tokens
• Batch extended-output beta: up to 300k output tokens with output-300k-2026-03-24 beta header
• Capabilities: text + image input, text output, multilingual, vision; adaptive thinking supported; extended thinking listed as No
• Pricing: model overview lists $3/MTok input and $15/MTok output with an introductory-pricing footnote; pricing page lists Claude Sonnet 5 introductory pricing through 2026-08-31 and standard pricing starting 2026-09-01. Verify exact first-party vs batch table placement before encoding final cost claims.
• Lifecycle/deprecations: model deprecations page notes temperature, top_p, and top_k are deprecated on Claude Sonnet 5, returning 400 when set to non-default values.

Graph delta needed

Add/update Atlas graph records for:

• New ModelVersion / compute model record: model:claude-sonnet-5@current
• Family edge under the Claude Sonnet family
• Provider edges for provider:anthropic, and provider/platform aliases for Bedrock and Vertex where local patterns support this
• EvidenceSource records for Anthropic model overview, pricing, and deprecation docs
• Claim records for model ID, provider aliases, context window, max output, modalities, adaptive thinking, non-support for extended thinking, pricing, cloud availability, lifecycle status, and deprecated parameter behavior
• Transport/protocol support through Anthropic Messages API; Bedrock/Vertex compatibility should follow existing Claude 4.8 and Fable/Mythos sidecar patterns

Existing graph observations

• rg "claude-sonnet-5|Sonnet 5" packages/atlas/graph finds agent-version/release-note references, but no compute model record for model:claude-sonnet-5@current.
• Existing patterns to reuse: packages/atlas/graph/compute/models/model-issue-532.yaml for Claude Opus 4.8 and packages/atlas/graph/compute/models/claude-fable-5.yaml / claude-mythos-5.yaml.

Transport-adapter proxy impact

The model uses the Anthropic Messages API and existing Anthropic/Bedrock/Vertex Claude transport paths should support the required API shape. The graph update should verify whether any adapter model allowlists or default-model mappings need to include claude-sonnet-5 explicitly.

[a5c-ai]

Tracked Claude Sonnet 5 in Atlas graph on branch model-versions/daily-2026-07-04.\n\nPR: https://github.com/a5c-ai/babysitter/pull/1181\n\nVerification: npm run build --workspace=@a5c-ai/atlas passed.

[a5c-ai]

Triage Summary

• One-line: Add source-backed Atlas graph coverage for claude-sonnet-5 as a current Anthropic model version.

Critical Evaluation

• Reporter's analysis is accurate: the current checked-out graph lacks model:claude-sonnet-5@current; local Sonnet 5 hits are only adapter test placeholder successor IDs.
• This is a catalog freshness/enhancement issue, not a runtime outage.
• PR Track Claude Sonnet 5 in Atlas graph #1181 is the active implementation path and explicitly closes this issue, but it is still open, so main/staging should not be treated as fixed yet.

Root Cause Analysis

• Affected graph patterns:
  • packages/atlas/graph/compute/models/claude-sonnet-4-6.yaml shows the existing ModelVersion shape, capability fields, served_by, and Anthropic Messages transport edge pattern.
  • packages/atlas/graph/compute/model-families/claude-sonnet-4.yaml currently links Sonnet 4.5/4.6 only.
  • packages/atlas/graph/compute/providers/anthropic.yaml serves existing Claude model records but does not list Sonnet 5 on the current branch.
  • packages/atlas/graph/catalog-meta/evidence-sources/ and packages/atlas/graph/catalog-meta/claims/ are the source-backed metadata locations to update.
• Evidence: rg -n 'model:claude-sonnet-5@current|claude-sonnet-5|anthropic.claude-sonnet-5' packages/atlas/graph packages/adapters docs -S --glob '!**/node_modules/**' finds no Atlas Sonnet 5 model record on the current branch.

Affected Components

• Packages: @a5c-ai/atlas, @a5c-ai/adapters
• Components: atlas, agent-catalog, adapters
• Effort: effort:medium

Recommended Approach

• Continue through PR Track Claude Sonnet 5 in Atlas graph #1181 unless it is superseded.
• Add/verify model:claude-sonnet-5@current, family linkage, Anthropic provider serving, Anthropic Messages transport support, evidence sources, and claims.
• Keep every provider alias, pricing detail, context/output limit, lifecycle, and thinking-capability claim source-backed.
• Do not infer Bedrock/Vertex/Foundry edges unless exact IDs are confirmed by official docs.

Reproduction

rg -n 'model:claude-sonnet-5@current|claude-sonnet-5|anthropic.claude-sonnet-5' packages/atlas/graph packages/adapters docs -S --glob '!**/node_modules/**'

Expected on current branch: no Atlas graph ModelVersion for Sonnet 5; only adapter placeholder successor IDs appear.

Related Issues/PRs

• Related predecessor: Track Claude Sonnet 5 #1084, closed, broader Sonnet 5 tracking.
• Active implementation: Track Claude Sonnet 5 in Atlas graph #1181.

Priority

priority:medium

Important for Atlas/model-catalog correctness and downstream graph consumers, but not a crash/data-loss issue. The implementation path is bounded and already in progress.

Risk Analysis

• Risk Level: risk:medium
• Unverified provider aliases or availability could mislead adapter/proxy routing and catalog consumers.
  • Mitigation: only add provider edges and IDs backed by official docs; omit or mark open questions for unconfirmed providers.
• Capability or pricing data copied from Sonnet 4.6 could be wrong for Sonnet 5.
  • Mitigation: verify current docs for context window, max output, adaptive thinking, extended thinking support, modalities, lifecycle, and pricing windows.
• Graph sidecar IDs or edges could create duplicate or invalid catalog records.
  • Mitigation: run npm run build --workspace=@a5c-ai/atlas, npm run validate:edges, and npm run verify:metadata before merge.

Ready for development.