Provider Routing: Switch Models Without Rewriting the App

Build a small model router that can send easy, private, or expensive tasks to the right model family.

22 min · Reviewed 2026

What the local Hermes build teaches

This build lab focuses on the provider router that lets Hermes-style systems choose models by job instead of by brand loyalty. The goal is not to copy a private machine setup. The goal is to learn the architecture pattern well enough to build a small, classroom-safe version.

The app calls one router interface; the router decides whether to use local Hermes, a hosted open model, or a frontier API based on privacy, difficulty, latency, and budget.

Hermes pattern	Student build	Risk to handle
Name the boundary	a routing table with task labels, preferred providers, fallback providers, and escalation rules	hard-coding one model everywhere and discovering too late that privacy, cost, or quality needs changed
Keep the interface small	Start with one happy path and one failure path	Avoid a demo that only works when everything is perfect
Make the system observable	Log decisions, status, and errors in plain language	Do not log private data or secrets

Build the small version

Draw or write a routing table with task labels, preferred providers, fallback providers, and escalation rules.
Mark which parts are user-facing, which parts are internal, and which parts require approval.
Choose one low-risk workflow and implement only that workflow first.
Add one failure case before adding a second feature.
Write a short operator note: what the agent may do, what it must ask about, and what it must never do.

route(request): if request.contains_private_data: return local_hermes if request.needs_long_reasoning: return frontier_reasoning_model if request.is_batch_or_low_stakes: return cheap_open_model return default_chat_modelA classroom-safe skeleton inspired by the local Hermes architecture scan.

The big idea: router is not decoration. It is part of the product architecture students need before an agent becomes safe enough to use with real people.

End-of-lesson check

8 questions · take it digitally for instant feedback at tendril.neural-forge.io/learn/quiz/end-hermes-provider-router-creators

What is the main idea of "Provider Routing: Switch Models Without Rewriting the App"?
1. Build a small model router that can send easy, private, or expensive tasks to the right model family.
2. Use AI as the final authority for the whole decision
3. Avoid checking the answer once it sounds polished
4. Focus only on speed instead of judgment
Which concept is most central to "Provider Routing: Switch Models Without Rewriting the App"?
1. model-agnostic app
2. provider router
3. fallback
4. routing policy
Which use of AI fits this topic best?
1. Let the AI decide what matters without your review
2. Use the answer before checking whether it fits the situation
3. Draw or write a routing table with task labels, preferred providers, fallback providers, and escalation rules.
4. Treat the AI output as automatically correct
What should a careful learner remember about "From the local Hermes scan"?
1. Use AI to draft or organize ideas about provider router, then verify before acting.
2. Skip the context so the tool can guess faster
3. Treat the output as private even after sharing it online
4. Use the answer without checking the source
You want to use AI after this lesson. What is the safest next step?
1. Act immediately because the AI answer is written clearly
2. Use AI for drafting and comparison, but verify before publishing or relying on it.
3. Hide uncertainty so the final answer looks cleaner
4. Use private or sensitive details before checking permission
How should AI output about provider router be treated?
1. As proof that no other source is needed
2. As a replacement for context, consent, or expert review
3. As a draft or helper output that still needs human judgment and verification
4. As something that becomes correct when it sounds confident
Name one way to verify an AI answer about provider router.
Which action would help you apply "Provider Routing: Switch Models Without Rewriting the App" responsibly?
1. Use the tool to avoid thinking through the tradeoff
2. Keep going even if the output conflicts with a trusted source
3. Treat the AI output as automatically correct
4. Mark which parts are user-facing, which parts are internal, and which parts require approval.

← Back to interactive lesson

Tendril · Creators · Agentic AI

Provider Routing: Switch Models Without Rewriting the App

Build a small model router that can send easy, private, or expensive tasks to the right model family.

22 min · Reviewed 2026

What the local Hermes build teaches

The app calls one router interface; the router decides whether to use local Hermes, a hosted open model, or a frontier API based on privacy, difficulty, latency, and budget.

Hermes pattern	Student build	Risk to handle
Name the boundary	a routing table with task labels, preferred providers, fallback providers, and escalation rules	hard-coding one model everywhere and discovering too late that privacy, cost, or quality needs changed
Keep the interface small	Start with one happy path and one failure path	Avoid a demo that only works when everything is perfect
Make the system observable	Log decisions, status, and errors in plain language	Do not log private data or secrets

Build the small version

Draw or write a routing table with task labels, preferred providers, fallback providers, and escalation rules.
Mark which parts are user-facing, which parts are internal, and which parts require approval.
Choose one low-risk workflow and implement only that workflow first.
Add one failure case before adding a second feature.
Write a short operator note: what the agent may do, what it must ask about, and what it must never do.

route(request): if request.contains_private_data: return local_hermes if request.needs_long_reasoning: return frontier_reasoning_model if request.is_batch_or_low_stakes: return cheap_open_model return default_chat_modelA classroom-safe skeleton inspired by the local Hermes architecture scan.

The big idea: router is not decoration. It is part of the product architecture students need before an agent becomes safe enough to use with real people.

End-of-lesson check

8 questions · take it digitally for instant feedback at tendril.neural-forge.io/learn/quiz/end-hermes-provider-router-creators

What is the main idea of "Provider Routing: Switch Models Without Rewriting the App"?
1. Build a small model router that can send easy, private, or expensive tasks to the right model family.
2. Use AI as the final authority for the whole decision
3. Avoid checking the answer once it sounds polished
4. Focus only on speed instead of judgment
Which concept is most central to "Provider Routing: Switch Models Without Rewriting the App"?
1. model-agnostic app
2. provider router
3. fallback
4. routing policy
Which use of AI fits this topic best?
1. Let the AI decide what matters without your review
2. Use the answer before checking whether it fits the situation
3. Draw or write a routing table with task labels, preferred providers, fallback providers, and escalation rules.
4. Treat the AI output as automatically correct
What should a careful learner remember about "From the local Hermes scan"?
1. Use AI to draft or organize ideas about provider router, then verify before acting.
2. Skip the context so the tool can guess faster
3. Treat the output as private even after sharing it online
4. Use the answer without checking the source
You want to use AI after this lesson. What is the safest next step?
1. Act immediately because the AI answer is written clearly
2. Use AI for drafting and comparison, but verify before publishing or relying on it.
3. Hide uncertainty so the final answer looks cleaner
4. Use private or sensitive details before checking permission
How should AI output about provider router be treated?
1. As proof that no other source is needed
2. As a replacement for context, consent, or expert review
3. As a draft or helper output that still needs human judgment and verification
4. As something that becomes correct when it sounds confident
Name one way to verify an AI answer about provider router.
Which action would help you apply "Provider Routing: Switch Models Without Rewriting the App" responsibly?
1. Use the tool to avoid thinking through the tradeoff
2. Keep going even if the output conflicts with a trusted source
3. Treat the AI output as automatically correct
4. Mark which parts are user-facing, which parts are internal, and which parts require approval.

← Back to interactive lesson