OpenRouter to KeepRouter migration: map URLs, model IDs and routing fields

Move a compatible text flow first, with an explicit mapping from its OpenRouter configuration to a current KeepRouter model and endpoint. Provider policies, fallback settings and stateful objects need separate review; changing the host cannot translate them.

Published 2026-09-23 · Updated 2026-09-29 · KeepRouter Editorial · 6 minute read

An OpenRouter to KeepRouter migration is concrete when another developer can reproduce the old and new requests, explain each changed field, and switch the feature back. Start with one stateless text feature that already has an acceptance test. Broader platform comparisons belong in the OpenRouter comparison; this guide is the request-level runbook.

The candidate route must exist in the current catalog and support the operation your feature uses. An entry such as Claude Sonnet 4.6 provides a public KeepRouter ID and endpoint information. Do not derive target IDs by stripping a provider prefix from an OpenRouter slug. Make an explicit mapping and verify it.

Check the configuration locally

Use the API migration checker with credential-free JSON and an explicit target model. Download the Python and Node starter pack for dry-run, streaming and tool-continuation examples. These static and synthetic checks do not prove live upstream compatibility.

Write the configuration mapping before changing code

OpenRouter documents provider ordering and fallback controls in its request contract. KeepRouter's upstream mappings are operator-managed; an OpenRouter provider policy is not a portable way to select those mappings. If selecting a specific provider or region is a hard requirement and no equivalent public control exists, that workflow does not pass the migration checklist.

Keep both client profiles explicit

The following Python setup creates clients but makes no API call. Put the exact verified model IDs in environment variables rather than relying on a string transformation. Store secrets in the runtime's secret mechanism.

import os
from openai import OpenAI

profiles = {
    "old": {
        "base_url": "https://openrouter.ai/api/v1",
        "api_key": os.environ["OPENROUTER_API_KEY"],
        "model": os.environ["OPENROUTER_MODEL"],
    },
    "candidate": {
        "base_url": "https://keeprouter.com/v1",
        "api_key": os.environ["KEEPROUTER_KEY"],
        "model": os.environ["KEEPROUTER_MODEL"],
    },
}

def client_for(name):
    profile = profiles[name]
    return OpenAI(
        base_url=profile["base_url"],
        api_key=profile["api_key"],
        timeout=30.0,
        max_retries=0,
    ), profile["model"]

The application should select one profile for a canary, not duplicate every production request to both services automatically. Shadow evaluation needs an explicit data and cost decision. For a first comparison, use synthetic or approved test fixtures and a bounded request count. Keep prompt contents and credentials out of diagnostic logs.

Inventory OpenRouter-specific behavior

Search your request builder for provider preferences, fallback model arrays, transforms, plugins, routing aliases and attribution headers. Classify each field as required behavior, optional behavior or historical configuration. Compare the required items with the KeepRouter API contract and routing description.

Do not silently remove a field that enforced a meaningful requirement just to obtain a successful response. Conversely, do not carry undocumented fields into the new request and assume they took effect because the server accepted the JSON. The migration record should state which behavior was retained, replaced or left on the old path.

Review any use of native OpenRouter SDK methods separately from the OpenAI SDK. A native SDK can expose OpenRouter account, routing or discovery operations that have no corresponding method on another service. Keeping the ordinary Chat Completions path small makes the first migration easier to inspect.

Require a complete request lifecycle

Run a non-streaming request first and verify the returned content against the feature's acceptance criteria. Then exercise the following cases with the same model mapping and client version:

This article supplies the cases, not test results. Record date, SDK version, exact payload, status and request identifiers when you run them. If the application uses Responses state or another provider-owned resource, verify how it is recreated at the destination. An existing response identifier is not a cross-service conversation export.

Compare bills using accepted tasks

The two paths can differ in output length, cache behavior and number of attempts. Compare cost per accepted task and retain the raw usage for each attempt. Select the target KeepRouter model in the API cost calculator for an initial estimate. Calculate the OpenRouter path separately from its own customer rates, then reconcile the actual debit. Keep any top-up or separately billed service charges visible in the business comparison.

For example, choose twenty fixed support-ticket fixtures and the same pass criteria. Count completed acceptable summaries, not just successful HTTP responses. If one path requires additional repair calls, include them. Do not publish a savings claim from list prices alone, and do not infer equal upstream service from similar public model names.

Make rollback restore the whole client profile

Keep the old base URL, credential reference, model ID and product-specific options in one configuration profile. A rollback that restores only the URL can send a KeepRouter model ID or key to OpenRouter. Test the profile switch with a harmless fixed prompt before cutover. OpenRouter’s quickstart documents its client configuration; the KeepRouter profile above must remain separate. Never print either key while diagnosing the switch.

Roll out and roll back as a configuration unit

Keep host, key reference, model mapping, request-field policy and parser version together. Move a limited application feature or a controlled traffic slice, observe its request records, and expand only after the acceptance conditions remain satisfied. Retain the previous profile until existing conversations and background jobs have a clear completion path.

A rollback must restore the whole profile. Restoring only the host can leave the wrong model ID, a provider-specific field, or the wrong stream parser in place. The general API migration checklist covers the wider rollout, while the SDK guide provides copyable client configuration.

Frequently asked questions

Can I convert an OpenRouter slug by removing its provider prefix?

Do not rely on that. Verify an explicit mapping to an exact current KeepRouter catalog ID.

Will OpenRouter provider.order work unchanged?

It is an OpenRouter-specific control. Verify the destination routing contract; KeepRouter upstream mappings are operator-managed.

Does an HTTP 200 complete the migration test?

No. Verify accepted content, stream termination, tool continuation, state and billing as required by the feature.

What must rollback restore?

The host, credential reference, model mapping, request-field policy and response parser together.

Sources reviewed

Article last reviewed 2026-09-29

1. [1] OpenRouter quickstart
2. [2] OpenRouter provider routing
3. [3] KeepRouter routing contract
4. [4] KeepRouter OpenAPI

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• KeepRouter vs OpenRouter
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• openai sdk
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