TXT CLAW Routing (Hosted Router Lane)

TXT CLAW supports two LLM lanes:

Hosted router (default): TXT CLAW pays the model bill and routes requests.
BYOK (optional): you bring a provider key (see
```
https://www.txtclaw.com/byok.md
```
).

This doc describes the hosted router behavior and the

llm

fields you can set on agent creation.

Hosted Router Defaults

```
llm.mode
```
:
```
hosted
```
(default)
```
llm.tier
```
:
```
fast
```
(default)
```
llm.model
```
: optional explicit override

Auto-Router (Primary + Fallback)

When configured, TXT CLAW can try a primary model and fall back to a smarter model on upstream failures.

How it works (conceptually):

Attempt 1: primary model (fast)
Attempt 2+: fallback model (smart), if configured

Create An Agent With Hosted Router

bash

export TXTCLAW_API_BASE_URL="https://txtclaw-sms-e2e.lopez731.workers.dev"
export TXTCLAW_API_KEY="vck_REPLACE_ME"

curl -sS "$TXTCLAW_API_BASE_URL/v1/agents" \
  -H "Authorization: Bearer $TXTCLAW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "system_prompt": "You are a helpful assistant. Keep replies concise.",
    "llm": { "mode": "hosted", "tier": "fast" },
    "sms": { "mode": "none" }
  }'

Force A Specific Model (Advanced)

bash

curl -sS "$TXTCLAW_API_BASE_URL/v1/agents" \
  -H "Authorization: Bearer $TXTCLAW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "system_prompt": "You are a helpful assistant.",
    "llm": { "mode": "hosted", "model": "openai/amazon/nova-lite" },
    "sms": { "mode": "none" }
  }'

Notes

The exact hosted models are an implementation detail; use
```
tier
```
unless you need a specific override.
If you’re wrapping TXT CLAW, treat
```
llm.model
```
as an advanced escape hatch, not a default.