--- title: "Model Reference" description: "Canonical September 2026 model IDs for every provider - the single source of truth for the model-ID integrity check." url: "https://agentsurface.dev/docs/reference-links/models" lastVerified: 2026-09-24 lastModified: 2026-09-25T05:46:01.000Z --- This is the canonical list of model IDs Agent Surface uses in examples. Every model-ID string in the docs and in the template kits must appear here. `scripts/check-docs-integrity.mjs` parses this page's code-formatted IDs into an allowlist and flags any model-ID-shaped string elsewhere in the corpus that is not on it - including bare Anthropic role aliases (`opus-4-7`) and prose model names (`Opus 4.8`). Update this page first, then run the sweep. Verified against provider documentation on 2026-09-24. ## Anthropic [#anthropic] | Model | API ID | Role | Notes | | --------- | --------------------------- | ------------------- | -------------------------------------------------------------------------------------------------- | | Fable 5.1 | `claude-fable-5-1` | Flagship | Supersedes Fable 5; highest-capability publicly available model for deep reasoning and long tasks. | | Opus 5.5 | `claude-opus-5-5` | Recommended default | Released 2026-09-22. Supersedes Opus 5; 1M context, effort control. | | Sonnet 5 | `claude-sonnet-5` | Balanced | Fast iteration and everyday agent loops. | | Haiku 4.5 | `claude-haiku-4-5-20251001` | Fast / low cost | Cheap evals, classification, high-volume calls. Dateless alias: `claude-haiku-4-5`. | Anthropic also lists **Mythos**, a restricted tier above Fable 5.1 gated to an allowlist of enterprise accounts. No public API ID is published for it; do not reference it in general examples. **Retired 2026-06-15:** Opus 4 and Sonnet 4. **Retired 2026-08-05:** Opus 4.1. Older pins from these eras - Opus 4.7, Opus 4.8, and Sonnet 4.6 - are no longer valid; the model-ID check flags them, including bare aliases and prose mentions. **Superseded 2026-09-22:** Opus 5 remains available in the API but is no longer the recommended default; Fable 5 remains available but is no longer the flagship pin. Replace default pins with `claude-opus-5-5`, flagship pins with `claude-fable-5-1`, and balanced pins with `claude-sonnet-5`. ## OpenAI [#openai] | Model | API ID | Role | Notes | | ------------- | --------------- | ---------- | ------------------------------------------------------------------------------ | | GPT-5.6 Sol | `gpt-5.6-sol` | Flagship | GA 2026-07-09. Deepest reasoning tier; the bare alias `gpt-5.6` routes to Sol. | | GPT-5.6 Terra | `gpt-5.6-terra` | Balanced | Mid tier - most capability per dollar for everyday agent work. | | GPT-5.6 Luna | `gpt-5.6-luna` | Value tier | Fastest and cheapest; the default wherever a cheaper OpenAI model is wanted. | **Superseded 2026-07-09:** GPT-5.5 and GPT-5.4 remain available but the GPT-5.6 tiers replace them in examples - the model-ID check flags remaining GPT-5.5/5.4 pins. The o-series reasoning models (o1, o3, o4 family) were deprecated in June 2026, with removal scheduled for December 2026. Do not use them in examples. ## Google [#google] | Model | API ID | Role | Notes | | ------------------------ | ------------------------ | -------- | -------------------------------------------------------------------------------------- | | Gemini 3.7 Flash | `gemini-3.7-flash` | Current | GA 2026-08. Default Google model for agent and eval examples. | | Gemini 3.6 Flash | `gemini-3.6-flash` | Previous | Stable previous-generation Flash model; retain only for deliberate compatibility pins. | | Gemini 3.5 Flash-Lite | `gemini-3.5-flash-lite` | Fast | GA 2026-07-21. Fastest 3.5-series model for high-volume, low-cost calls. | | Gemini 3.1 Pro (preview) | `gemini-3.1-pro-preview` | Preview | Higher-capability preview; still preview as of 2026-09-24 - pin the full ID. | **Superseded 2026-08:** Gemini 3.7 Flash replaces Gemini 3.6 Flash as the example default. Keep `gemini-3.6-flash` only where compatibility is deliberate. (Gemini 3.5 Pro is not listed because it has not reached GA.) ## Embeddings [#embeddings] | Model | API ID | Provider | Notes | | ---------------------- | ------------------------ | -------- | ---------------------------------------------------------------------------------------------------- | | Text Embedding 3 Large | `text-embedding-3-large` | OpenAI | High-dimensional; strongest OpenAI embedding. | | Text Embedding 3 Small | `text-embedding-3-small` | OpenAI | Cost-optimized sibling; still current, chosen for cheap/high-volume retrieval. | | Voyage 4 Large | `voyage-4-large` | Voyage | Highest-quality Voyage retrieval embedding. | | Voyage 4 | `voyage-4` | Voyage | Balanced Voyage embedding. | | Voyage 4 Lite | `voyage-4-lite` | Voyage | Lower cost / latency. | | Voyage 4 Nano | `voyage-4-nano` | Voyage | Smallest / cheapest Voyage embedding. | | Voyage Context 4 | `voyage-context-4` | Voyage | Contextualized-chunk embedding. | | Voyage Multimodal 3.5 | `voyage-multimodal-3-5` | Voyage | Current Voyage multimodal model - text, image, and video embeddings in one space. | | Cohere Embed v4 | `embed-v4` | Cohere | Multimodal (text + image); Matryoshka dimensions (256-1536). Pair with `rerank-3.5` or `rerank-4.0`. | | Gemini Embedding 2 | `gemini-embedding-2` | Google | Google's current embedding model. | ## Anti-pattern example IDs [#anti-pattern-example-ids] Some docs deliberately show outdated model IDs as examples of what *not* to ship. These are exempt from the model-ID check because their staleness is the point of the example. This section is their allowlist - keep it in sync with the anti-pattern docs. | ID | Where | Why exempt | | ----------------- | --------------------------------- | --------------------------------------------------------------------------------------------- | | `claude-3-sonnet` | `context-files/anti-patterns.mdx` | Deliberately-stale model pin in the "auto-generated boilerplate nobody curates" anti-pattern. |