I need a shortlist of AI APIs that have good docs, stable SDKs, and support for structured JSON output.

Here’s a practical shortlist of AI APIs that are generally strong on documentation, SDK stability, and structured JSON output:

Best overall candidates

1) OpenAI API

• Docs: Excellent, widely used, very clear examples
• SDKs: Strong official SDKs; generally stable and well maintained
• Structured JSON output: Yes — supports structured outputs / JSON schema-style responses
• Why it’s a good pick: Probably the easiest “safe choice” if you want good developer experience and reliable structured responses

2) Anthropic API

• Docs: Very good and improving steadily
• SDKs: Official SDKs are solid
• Structured JSON output: Yes — can be done reliably with prompting and tool-use patterns; support for structured responses is good, though implementation style may differ from OpenAI’s
• Why it’s a good pick: Strong model quality and clean API design, especially if you value reasoning and long context

3) Google Gemini API

• Docs: Good, with decent examples and platform integration
• SDKs: Official SDKs available and generally stable
• Structured JSON output: Yes — supports JSON output / structured responses in supported modes
• Why it’s a good pick: Good option if you’re already in Google Cloud / Vertex AI ecosystem

4) AWS Bedrock

• Docs: Good, though sometimes more enterprise/platform-focused than developer-first
• SDKs: Very stable via AWS SDKs
• Structured JSON output: Yes, depending on the underlying model/provider and feature set
• Why it’s a good pick: Best if you need enterprise controls, IAM integration, and multiple model providers under one roof

5) Cohere

• Docs: Good and fairly developer-friendly
• SDKs: Stable official SDKs
• Structured JSON output: Supported via tool use / response formatting patterns depending on endpoint/model
• Why it’s a good pick: Strong enterprise focus and good API ergonomics

Quick ranking by “developer experience + structured output”

1. OpenAI
2. Anthropic
3. Google Gemini
4. Cohere
5. AWS Bedrock
   (Though Bedrock can move up if your priority is enterprise integration over simplicity.)

What to look for before choosing

To verify “good docs + stable SDKs + JSON output,” check:

• Official SDK release cadence and semver adherence
• Whether the provider supports JSON schema / constrained output rather than “best effort JSON”
• Tool/function calling support
• Clear examples for:
  • structured extraction
  • retries / validation
  • streaming
• How they handle:
  • malformed JSON
  • schema mismatches
  • model/version changes

My recommendation

If you want the safest shortlist to evaluate first:

• OpenAI
• Anthropic
• Google Gemini
• AWS Bedrock if enterprise matters
• Cohere as a strong alternative

If you want, I can also turn this into a comparison table with:

• pricing posture,
• JSON schema support,
• SDK maturity,
• and best use cases.