Claude Opus 4.8

Most capable Opus-tier model: state-of-the-art long-horizon agentic execution, knowledge work and memory. 1M context at standard pricing.

name
Claude Opus 4.8
vendor
Anthropic
model_id
claude-opus-4-8
context_window
1M
max_output
128K
input_per_mtok
$5.00
output_per_mtok
$25.00
strengths
Most capable Opus-tier model: state-of-the-art long-horizon agentic execution, knowledge work and memory. 1M context at standard pricing.
provider
Anthropic
family
Claude Opus
release_date
2026-05-28 source
last_updated
2026-06-15
open_weights
false source
license
proprietary source
params_total
— verify-against-primary-at-build ↗ Anthropic does not disclose parameter counts for Claude Opus 4.8.
params_active
— verify-against-primary-at-build ↗ Anthropic does not disclose parameter counts for Claude Opus 4.8.
tool_call
true source
reasoning
always source
structured_output
— verify-against-primary-at-build ↗ https://platform.claude.com/docs/en/about-claude/models/overview — schema-guaranteed structured-output flag not explicitly published for claude-opus-4-8 (no models.dev entry yet).
attachment
image source
temperature
— verify-against-primary-at-build ↗ https://platform.claude.com/docs/en/about-claude/models/overview — temperature-control flag not explicitly stated for claude-opus-4-8.
knowledge_cutoff
2026-01 source
context_advertised
1M source
context_effective
— verify-against-primary-at-build ↗ No published measured long-context recall benchmark for claude-opus-4-8; do not derive effective context from advertised.
price_input
$5.00 source
price_output
$25.00 source
price_cache_read
— verify-against-primary-at-build ↗ https://platform.claude.com/docs/en/about-claude/pricing — cache-read rate for claude-opus-4-8 not captured numerically in fetched sources.
price_cache_write
— verify-against-primary-at-build ↗ https://platform.claude.com/docs/en/about-claude/pricing — cache-write rate for claude-opus-4-8 not captured numerically in fetched sources.
cost_per_full_window
— verify-against-primary-at-build ↗ Derived at build: price_input × advertised context once cache context is confirmed.
cost_per_agent_task
— verify-against-primary-at-build ↗ Derived at build from the cache-aware agent-task model once cache rates are confirmed.
modalities
text-in,image-in,text-out source
gpqa_diamond
— verify-against-primary-at-build ↗ https://www.anthropic.com/news — benchmark number not captured from a primary leaderboard in this pass.
swe_bench_verified
— verify-against-primary-at-build ↗ https://www.swebench.com/ — SWE-bench Verified score for claude-opus-4-8 to confirm at build.
terminal_bench
— verify-against-primary-at-build ↗ https://www.tbench.ai/ — Terminal-Bench score for claude-opus-4-8 to confirm at build.
tau2_bench
— verify-against-primary-at-build ↗ Primary τ²-Bench leaderboard — score for claude-opus-4-8 to confirm at build.
bfcl_tool_use
— verify-against-primary-at-build ↗ https://gorilla.cs.berkeley.edu/leaderboard.html — BFCL tool-use score for claude-opus-4-8 to confirm at build.
aa_index
— verify-against-primary-at-build ↗ https://artificialanalysis.ai/ — Intelligence Index for claude-opus-4-8 to confirm at build.
lmarena_elo
— verify-against-primary-at-build ↗ https://lmarena.ai/leaderboard — human-preference Elo for claude-opus-4-8 to confirm at build.
tokens_per_sec
— verify-against-primary-at-build ↗ https://artificialanalysis.ai/ — measured throughput for claude-opus-4-8 to confirm at build.
ttft
— verify-against-primary-at-build ↗ https://artificialanalysis.ai/ — measured time-to-first-token for claude-opus-4-8 (overview lists Comparative latency: Moderate).
hallucination_rate
— verify-against-primary-at-build ↗ No primary hallucination benchmark captured for claude-opus-4-8 in this pass.
agent_readiness_score
— verify-against-primary-at-build ↗ Score withheld: R_tool (BFCL/τ²-Bench), R_ctx (effective context), R_cost (cache rates) and R_latency inputs not yet sourced. Compute per /models/agent-readiness-score once inputs confirmed.
score_confidence
partial
source_url
https://platform.claude.com/docs/en/about-claude/models/overview
source_type
provider_card
last_verified
2026-06-15

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