Only use exact model IDs listed in this file.
Only use exact model IDs listed in this file. Never guess or construct model IDs — incorrect IDs will cause API errors. Use aliases wherever available. For the latest information, WebFetch the Models Overview URL in shared/live-sources.md, or query the Models API directly (see Programmatic Model Discovery below).
For live capability data — context window, max output tokens, feature support (thinking, vision, effort, structured outputs, etc.) — query the Models API instead of relying on the cached tables below. Use this when the user asks "what's the context window for X", "does model X support vision/thinking/effort", "which models support feature Y", or wants to select a model by capability at runtime.
m = client.models.retrieve("claude-opus-4-8")
m.id # "claude-opus-4-8"
m.display_name # "Claude Opus 4.8"
m.max_input_tokens # context window (int)
m.max_tokens # max output tokens (int)
# capabilities is an untyped nested dict — bracket access, check ["supported"] at the leaf
caps = m.capabilities
caps["image_input"]["supported"] # vision
caps["thinking"]["types"]["adaptive"]["supported"] # adaptive thinking
caps["effort"]["max"]["supported"] # effort: max (also low/medium/high)
caps["structured_outputs"]["supported"]
caps["context_management"]["compact_20260112"]["supported"]
# filter across all models — iterate the page object directly (auto-paginates); do NOT use .data
[m for m in client.models.list()
if m.capabilities["thinking"]["types"]["adaptive"]["supported"]
and m.max_input_tokens >= 200_000]Top-level fields (id, display_name, max_input_tokens, max_tokens) are typed attributes. capabilities is a dict — use bracket access, not attribute access. The API returns the full capability tree for every model with supported: true/false at each leaf, so bracket chains are safe without .get() guards. TypeScript SDK: same method names, also auto-paginates on iteration.
curl https://api.anthropic.com/v1/models/claude-opus-4-8 \
-H "x-api-key: $ANTHROPIC_API_KEY" \
-H "anthropic-version: 2023-06-01"{
"id": "claude-opus-4-8",
"display_name": "Claude Opus 4.8",
"max_input_tokens": 1000000,
"max_tokens": 128000,
"capabilities": {
"image_input": {"supported": true},
"structured_outputs": {"supported": true},
"thinking": {"supported": true, "types": {"enabled": {"supported": false}, "adaptive": {"supported": true}}},
"effort": {"supported": true, "low": {"supported": true}, …, "max": {"supported": true}},
…
}
}| Friendly Name | Alias (use this) | Full ID | Context | Max Output | Status | |-------------------|---------------------|-------------------------------|----------------|------------|--------| | Claude Fable 5 | claude-fable-5 | — | 1M | 128K | Active | | Claude Mythos 5 | claude-mythos-5 | — | 1M | 128K | Active (Project Glasswing only) | | Claude Opus 5 | claude-opus-5 | — | 1M | 128K | Active | | Claude Opus 4.8 | claude-opus-4-8 | — | 1M | 128K | Active | | Claude Opus 4.7 | claude-opus-4-7 | — | 1M | 128K | Active | | Claude Opus 4.6 | claude-opus-4-6 | — | 1M | 128K | Active | | Claude Sonnet 5 | claude-sonnet-5 | — | 1M | 128K | Active | | Claude Sonnet 4.6 | claude-sonnet-4-6 | - | 1M | 128K | Active | | Claude Haiku 4.5 | claude-haiku-4-5 | claude-haiku-4-5-20251001 | 200K | 64K | Active |
thinking: {type: "disabled"} returns a 400 — omit the thinking parameter instead (thinking is always on; the raw chain of thought is never returned — summaries via display: "summarized"). Same tokenizer as Opus 4.8 (token counts roughly unchanged vs Opus 4.7/4.8). Safety classifiers may return stop_reason: "refusal". No assistant prefill. Requires 30-day data retention (not available under ZDR). $10/$50 per MTok; 1M context window (default), 128K max output. See shared/model-migration.md → Migrating to Claude Fable 5.claude-mythos-preview). Use it only when the org participates in Project Glasswing; otherwise use claude-fable-5.stop_reason: "refusal" — handle it before reading content. A drop-in upgrade at Opus 4.8's pricing ($5/$25 per MTok) with the same feature set. Thinking is on by default (omitting thinking runs adaptive; {type: "adaptive"} is equivalent), and thinking: {type: "disabled"} is available only at effort high or lower — pairing it with xhigh/max returns a 400. Raw thinking tokens are never returned. Full effort ladder through max; 512-token prompt-cache minimum (down from 1024 on Opus 4.8); fast mode on the Claude API only. Elevated cybersecurity safeguards. Separate rate-limit bucket from the combined Opus 4.x pool. 1M context window (default and maximum), 128K max output. See shared/model-migration.md → Migrating to Claude Opus 5.budget_tokens removed). 1M context window at standard API pricing (no long-context premium). See shared/model-migration.md → Migrating to Opus 4.8 — a 4.7 → 4.8 move is a model-ID swap plus prompt re-tuning, no new breaking changes.budget_tokens removed. 1M context window. See shared/model-migration.md → Migrating to Opus 4.7.thinking runs adaptive); manual budget_tokens removed; non-default sampling parameters rejected. effort supports low/medium/high/xhigh/max. New tokenizer (~30% more tokens for the same text vs Sonnet 4.6). High-resolution vision (2576px). 1M context window, 128K max output. See shared/model-migration.md → Migrating to Claude Sonnet 5.| Friendly Name | Alias (use this) | Full ID | Status | |-------------------|---------------------|-------------------------------|--------| | Claude Opus 4.5 | claude-opus-4-5 | claude-opus-4-5-20251101 | Active | | Claude Opus 4.1 | claude-opus-4-1 | claude-opus-4-1-20250805 | Deprecated (retires 2026-08-05 — migrate to claude-opus-5) | | Claude Sonnet 4.5 | claude-sonnet-4-5 | claude-sonnet-4-5-20250929 | Active |
| Friendly Name | Alias (use this) | Full ID | Status | Retires | |-------------------|---------------------|-------------------------------|------------|--------------| | Claude Sonnet 4 | claude-sonnet-4-0 | claude-sonnet-4-20250514 | Deprecated | TBD | | Claude Opus 4 | claude-opus-4-0 | claude-opus-4-20250514 | Deprecated | TBD | | Claude Haiku 3 | — | claude-3-haiku-20240307 | Deprecated | Apr 19, 2026 |
| Friendly Name | Full ID | Retired | |-------------------|-------------------------------|-------------| | Claude Sonnet 3.7 | claude-3-7-sonnet-20250219 | Feb 19, 2026 | | Claude Haiku 3.5 | claude-3-5-haiku-20241022 | Feb 19, 2026 | | Claude Opus 3 | claude-3-opus-20240229 | Jan 5, 2026 | | Claude Sonnet 3.5 | claude-3-5-sonnet-20241022 | Oct 28, 2025 | | Claude Sonnet 3.5 | claude-3-5-sonnet-20240620 | Oct 28, 2025 | | Claude Sonnet 3 | claude-3-sonnet-20240229 | Jul 21, 2025 | | Claude 2.1 | claude-2.1 | Jul 21, 2025 | | Claude 2.0 | claude-2.0 | Jul 21, 2025 |
When a user asks for a model by name, use this table to find the correct model ID:
| User says... | Use this model ID | |-------------------------------------------|--------------------------------| | "fable", "most capable model" | claude-fable-5 | | "most powerful" | claude-fable-5 | | "mythos", "mythos 5" | claude-mythos-5 (Project Glasswing participants only; otherwise use claude-fable-5) | | "mythos preview" | claude-mythos-5 (successor to claude-mythos-preview — see migration guide) | | "opus" | claude-opus-5 | | "opus 5" | claude-opus-5 | | "opus 4.8" | claude-opus-4-8 | | "opus 4.7" | claude-opus-4-7 | | "opus 4.6" | claude-opus-4-6 | | "opus 4.5" | claude-opus-4-5 | | "opus 4.1" | claude-opus-4-1 (deprecated, retires 2026-08-05 — suggest claude-opus-5) | | "opus 4", "opus 4.0" | claude-opus-4-0 (deprecated — suggest claude-opus-5) | | "sonnet", "balanced" | claude-sonnet-5 | | "sonnet 5" | claude-sonnet-5 | | "sonnet 4.6" | claude-sonnet-4-6 | | "sonnet 4.5" | claude-sonnet-4-5 | | "sonnet 4", "sonnet 4.0" | claude-sonnet-4-0 (deprecated — suggest claude-sonnet-5) | | "sonnet 3.7" | Retired — suggest claude-sonnet-5 | | "sonnet 3.5" | Retired — suggest claude-sonnet-5 | | "haiku", "fast", "cheap" | claude-haiku-4-5 | | "haiku 4.5" | claude-haiku-4-5 | | "haiku 3.5" | Retired — suggest claude-haiku-4-5 | | "haiku 3" | Deprecated — suggest claude-haiku-4-5 |