Platform / Agent Adapters

Model-agnostic by design.

Capx does not lock you into one LLM. Use Claude, GPT, Codex, Cursor, or any HTTP endpoint as an agent backend. Switch models per agent, per task, or per playbook step.

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Claude

private beta

AnthropicOpus, Sonnet, Haiku

Strategy, writing, analysis, complex reasoning

adapter: claude
model: claude-sonnet-4-6
budget: 200
memory: persistent

GPT

private beta

OpenAIGPT-4o, GPT-4o-mini

General purpose, structured output, tool use

adapter: openai
model: gpt-4o
budget: 150
memory: persistent

HTTP

private beta

CustomAny endpoint

Proprietary models, internal APIs, fine-tuned models

adapter: http
config:
  endpoint: https://your-api.com/agent
  method: POST
  timeout: 30s
  retry: 3

Adapter registry

Every adapter is a first-class integration with typed schemas, automatic prompt formatting, and response parsing. One interface, many backends.

AdapterProviderModelsFeaturesUse caseStatus

ClaudeAnthropicOpus, Sonnet, HaikuPrompt caching, streaming, tool use, persistent memoryStrategy, writing, analysisprivate beta

GPTOpenAIGPT-4o, GPT-4o-miniStructured output, function calling, streamingGeneral purpose, code, dataprivate beta

CodexOpenAICodexCode generation, refactoring, static analysisEngineering tasksprivate beta

CursorCursorCursor AgentWorkspace access, file editing, test runningPR creation, code reviewprivate beta

HTTPCustomAny endpointCustom headers, auth, retries, timeoutFine-tuned models, internal APIsprivate beta

0adapters in private beta

Per-step model switching

Use the right model for each step. Research on Opus for depth. Drafting on Sonnet for speed and cost. Code samples on GPT-4o. Final review back on Opus.

Multi-model playbookresearch-and-write.yaml

playbook: research-and-write
steps:
  - name: research
    agent: strategist
    adapter: claude
    model: claude-opus-4
    tool: web-research

  - name: draft
    agent: marketer
    adapter: claude
    model: claude-sonnet-4-6
    tool: content-write

  - name: code-samples
    agent: engineer
    adapter: openai
    model: gpt-4o
    tool: code-generate

  - name: review
    agent: strategist
    adapter: claude
    model: claude-opus-4
    tool: content-review

researchAnthropic

claude-opus-4

Deep reasoning for comprehensive research

draftAnthropic

claude-sonnet-4-6

Fast and cost-effective for content drafting

code-samplesOpenAI

gpt-4o

Strong at structured code generation

reviewAnthropic

claude-opus-4

Deep reasoning for quality evaluation

Automatic fallback chains

Automatic fallback chains ensure continuity when a model is unavailable. Configure primary and fallback models per agent. Tasks are never dropped.

Primary

claude-sonnet-4-6

First choice. Used when available and within budget.

Fallback 1

gpt-4o

Automatic switch if Claude is unavailable or rate-limited.

Fallback 2

claude-haiku-4

Last resort. Lower cost, still capable for most tasks.

fallback:claude-sonnet-4-6->gpt-4o->claude-haiku-4->queue

Connect your first model.

Claude, GPT, Codex, Cursor, or your own HTTP endpoint. One interface, any backend.