Model capability probe

Anthropic: Claude Opus 4.1 | JSON mode

Whether Anthropic: Claude Opus 4.1 supports JSON mode cannot be decided from the name alone. Check model ID anthropic/claude-opus-4.1, provider Anthropic, catalog params, modality, a lightweight runtime probe, and the error body together.

Model

anthropic/claude-opus-4.1

Anthropic: Claude Opus 4.1

Provider

Anthropic

13 models in catalog

Capability

JSON mode

json-mode

Catalog signal

catalog shows support

Context: 200,000

Capability probe summary

Model

anthropic/claude-opus-4.1

Capability

json-mode

Catalog signal

catalog shows support

Read-only check. Detection data burns after 5 minutes.

How to judge this capability

Whether Anthropic: Claude Opus 4.1 supports JSON mode cannot be decided from the name alone. Check model ID anthropic/claude-opus-4.1, provider Anthropic, catalog params, modality, a lightweight runtime probe, and the error body together.

Model: anthropic/claude-opus-4.1
Provider: Anthropic
Capability: JSON mode

How to prove it during checking

Read-only check. Detection data burns after 5 minutes.

Start with the catalog signal: catalog shows support, then verify with a real key in read-only mode.
The capability probe must bind model ID anthropic/claude-opus-4.1; do not test another model from the same provider.
JSON mode · supports include_reasoning · supports max_tokens · supports reasoning · supports response_format

Next action

Anthropic: Claude Opus 4.1 JSON mode should turn into an operator action: confirm sale tags, fill the capability matrix, change route, suggest a fallback model, or mark unsupported for now.

Read-only check. Detection data burns after 5 minutes.
Catalog signal: catalog shows support
Context: 200,000

Open key checker

Read-only check. Detection data burns after 5 minutes.

Open models

Anthropic: Claude Opus 4.1

Open providers

Anthropic