# OpenAI, Anthropic, and text rendering

`ContextPack` is provider neutral. Render only after selection and policy evaluation so the same pack and manifest can be inspected independently of an SDK.

## Role mapping in the 0.1 series

| Cognoxium role | `to_openai()` | `to_anthropic()` | `to_text()` |
| --- | --- | --- | --- |
| `system` | `system` input message | Appended to top-level `system` text | `[system] ...` |
| `developer` | `developer` input message | Appended to top-level `system` text | `[developer] ...` |
| `user` | `user` input message | `user` message | `[user] ...` |
| `assistant` | `assistant` input message | `assistant` message | `[assistant] ...` |
| `tool` | `user` with `[tool result]` prefix | `user` with `[tool result]` prefix | `[tool] ...` |

Tool-call IDs and provider-specific tool-result objects are not preserved in the 0.1 series. Use a custom `Renderer` when your application requires those fields.

## Inspect the generated shapes

```{testcode}
import cognoxium as cx

pack = cx.CognitionFrame.from_records([
    {"id": "policy", "payload": "Be concise.", "role": "system",
     "sources": ["app://policy"], "trust": "trusted", "retention": "required",
     "created_at": "2026-01-01T00:00:00Z"},
    {"id": "tool", "payload": "42", "role": "tool",
     "sources": ["tool://calculator"], "created_at": "2026-01-01T00:01:00Z"},
]).pack(budget=100)

openai_input = pack.to_openai()
anthropic_input = pack.to_anthropic()
print(openai_input[0]["role"], openai_input[0]["content"][0]["type"])
print(openai_input[1]["role"], openai_input[1]["content"][0]["text"])
print(anthropic_input["system"])
print(anthropic_input["messages"][0]["role"])
```

```{testoutput}
system input_text
user [tool result]
42
Be concise.
user
```

`to_openai()` returns a list of input-message mappings. `to_anthropic()` returns a mapping with `system` and `messages`. Provider SDKs evolve independently; compare these shapes with the SDK version your application pins before sending a production request.

## Payload mapping

- Text renders as its text value.
- JSON renders as its canonical compact JSON string.
- Reference renders as its URI.
- Binary cannot enter a 0.1-series pack: optional/preferred items are excluded, while required items raise `UnsupportedContent`.

No renderer fetches a Reference URI. Resolving, authenticating, and authorizing a reference is the host application's responsibility.

## Custom renderers

Call `pack.render(renderer)`. A custom renderer receives the immutable pack and should raise `UnsupportedContent` rather than silently stringifying a payload it cannot represent. See {doc}`plugins`.