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Documentation Index

Fetch the complete documentation index at: https://docs.endprompt.ai/llms.txt

Use this file to discover all available pages before exploring further.

Endprompt supports multiple LLM providers, giving you flexibility to choose the best model for each use case.

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Supported Providers

OpenAI

GPT-4o, GPT-3.5-turbo, gpt-image-1

Anthropic

Claude 3 Opus, Sonnet, Haiku

Google

Gemini 2.0 Flash, Gemini 2.5 Pro

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Model Comparison

ModelProviderSpeedQualityCostVisionImage GenBest For
GPT-4oOpenAIFastExcellentMedium✅❌General purpose, vision, balanced
GPT-4OpenAIMediumExcellentHigh✅❌Complex reasoning
GPT-3.5-turboOpenAIVery FastGoodLow❌❌Simple tasks, high volume
gpt-image-1OpenAIMediumExcellentPer-image❌✅Image generation and editing
Claude 3 OpusAnthropicMediumExcellentHigh✅❌Nuanced analysis, long context
Claude 3 SonnetAnthropicFastVery GoodMedium✅❌Balanced performance
Claude 3 HaikuAnthropicVery FastGoodLow✅❌Fast responses, simple tasks
Gemini 2.0 FlashGoogleVery FastGoodLow✅❌Fast multimodal tasks
Gemini 2.5 ProGoogleMediumExcellentMedium✅❌Complex reasoning, long context

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Choosing a Model

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For Quality-Critical Tasks

  • GPT-4o or Claude 3 Opus
  • Complex analysis, nuanced responses
  • Higher cost, worth it for important outputs

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For High-Volume Tasks

  • GPT-3.5-turbo or Claude 3 Haiku
  • Simple classification, extraction
  • Low cost, high throughput

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For Long Documents

  • Claude 3 models
  • Support up to 200K tokens context
  • Ideal for document analysis

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For Image Tasks

  • Vision (image inputs): GPT-4o, Claude 3 models, Gemini — analyze images alongside text prompts
  • Image Generation (image outputs): gpt-image-1 — generate or edit images from text descriptions
  • Image Editing: Use gpt-image-1 with both image inputs and outputs to edit existing images

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Model Capabilities

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Context Window

How much input each model can handle:
ModelMax Input Tokens
GPT-4o128,000
GPT-4128,000
GPT-3.5-turbo16,385
Claude 3 Opus200,000
Claude 3 Sonnet200,000
Claude 3 Haiku200,000
For very long documents, Claude models offer the largest context windows.

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JSON Mode

Some models support native JSON output mode:
ModelJSON Mode
GPT-4o✅ Supported
GPT-4✅ Supported
GPT-3.5-turbo✅ Supported
Claude 3 modelsVia prompting
JSON mode is enabled automatically when you define an output schema.

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Model Selection in Prompts

When creating or editing a prompt:
  1. Click the Model dropdown
  2. Select your preferred model
  3. The model is saved with the prompt
Different prompts on the same endpoint can use different models—useful for A/B testing.

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Cost Considerations

LLM costs are based on tokens:
  • Input tokens: Your prompt text (including rendered template)
  • Output tokens: The model’s response
Cost FactorImpact
Model choiceHigher-end models cost more per token
Prompt lengthLonger prompts = more input tokens
Response lengthHigher max_tokens = potentially more output tokens
Request volumeMore requests = more total cost
Start with a capable model (GPT-4o), then optimize to cheaper models for tasks where quality remains acceptable.

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Model-Specific Tips

GPT-4o is the recommended default:
  • Best balance of speed, quality, and cost
  • Multimodal capabilities (can process images)
  • Reliable JSON output
Tips:
  • Use temperature 0-0.3 for deterministic tasks
  • Enable JSON mode for structured output
  • GPT-3.5-turbo is 10x cheaper for simple tasks

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Adding Provider API Keys

Your tenant needs API keys configured for each provider you want to use:
  1. Go to LLM API Keys in the sidebar (under Configuration)
  2. Add your OpenAI and/or Anthropic API keys
  3. Keys are encrypted and stored securely
Without a valid API key for a provider, prompts using that provider’s models will fail.

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Next Steps

Model Settings

Configure temperature, tokens, and more

API Authentication

Set up keys to call your endpoints