LinkModel API Documentation

Which Endpoint Should I Use?

Client behavior	Use
OpenAI Chat Completions-compatible client	`https://api.linkmodel.ai/v1/chat/completions`
Anthropic Messages-compatible client	`https://api.linkmodel.ai/v1/messages`
Codex or Responses API client	`https://api.linkmodel.ai/v1/responses`

Use the base URL https://api.linkmodel.ai/v1 when the agent appends endpoint paths automatically.

Check that the agent can read your environment variable:

echo "$LINKMODEL_API_KEY"

For Codex desktop apps or editor extensions, put the key in ~/.codex/.env and restart the app:

LINKMODEL_API_KEY=<YOUR_API_KEY>

For Claude Code, use ANTHROPIC_AUTH_TOKEN with the LinkModel key:

export ANTHROPIC_AUTH_TOKEN="$LINKMODEL_API_KEY"

Check the current model list:

https://docs.linkmodel.ai/models

Then use the exact model ID in the agent configuration.

Coding agents often send tool/function-calling fields. If the model rejects the request:

Use the endpoint matching the agent’s native protocol.
Try a coding-oriented model such as gpt-5.3-codex, gpt-5.6-sol, claude-opus-4-7, or deepseek-v4-pro.
Test with a smaller prompt before running a large coding task.

Check ~/.codex/config.toml:

model_provider = "linkmodel"

Then open /status in Codex and confirm the active provider.