Document Ask Fern LLM provider options

[devin-ai-integration]

Document Ask Fern LLM provider options

Summary

Adds documentation for the three LLM providers supported by Ask Fern: Anthropic, AWS Bedrock, and Cohere. This feature was added in fern-platform PR #5400 (Cohere support) but was not documented in the user-facing docs.

The new page explains:

• The three supported providers and their models
• How the fallback system works for high availability
• Configuration requirements for each provider

Review & Testing Checklist for Human

• Verify technical accuracy: Confirm model names (Claude 3.7, Claude 4 Sonnet, etc.) match customer-facing names and that "Command A 03 2025" is the correct Cohere model name
• Validate environment variables: Confirm ANTHROPIC_API_KEY and COHERE_API_KEY are the correct variable names used in production
• Check fallback order: Verify the provider preference order (Bedrock → Anthropic → Cohere) matches actual production configuration
• Review configuration section: Confirm whether LLM provider configuration is truly only available through Fern team contact, or if there's a self-service option I missed
• Test page rendering: View the page at /learn/ask-fern/llm-providers to ensure it renders correctly and navigation works

Test Plan

1. Navigate to the Ask Fern documentation section
2. Verify "LLM providers" appears in the Configuration section navigation
3. Click the link and confirm the page loads
4. Review content for accuracy against actual Ask Fern implementation
5. If possible, verify with someone who has configured Ask Fern that the information matches their experience

Notes

• Based on code review of fern-platform PR #5400 and the LLM factory implementation
• I documented all three providers (not just Cohere) for completeness, though the original request focused on Cohere
• The page assumes this is enterprise/infrastructure-level configuration; if there's a self-service option, the "Configuration" section should be updated
• Session: https://app.devin.ai/sessions/ef0744e80a96482a85c0f5cec53e4b4b
• Requested by: [email protected] (@dannysheridan)

[devin-ai-integration]

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[github-actions]

📝 [vale] _{reported by reviewdog 🐶}
[FernStyles.Headings] 'AWS Bedrock' should use sentence-style capitalization.

[github-actions]

📝 [vale] _{reported by reviewdog 🐶}
[FernStyles.Acronyms] 'IAM' has no definition.

[github-actions]

🌿 Preview your docs: https://fern-preview-4c4ed18f-4b47-4dc3-b0b8-8120fa462394.docs.buildwithfern.com/learn