Built for agent builders
Give agent loops explicit model, tool, and spend boundaries
Agent builders need more than an endpoint: long loops require model allowlists, spend limits, observable requests, and explicit retry rules. KeepRouter provides those gateway boundaries while your agent remains responsible for tool safety and task completion.
Last reviewed 2026-08-15 · Editorial review: KeepRouter Editorial
Treat the loop as a budgeted system
An agent can turn one user action into many model requests and tool calls. The model ID, maximum output, retry count, and key budget therefore belong in the runtime contract—not in a developer's local defaults. KeepRouter lets the loop use an OpenAI-compatible or Anthropic-compatible client surface while attributing requests to a scoped key.
Four controls before autonomy
- Restrict the key to tested model IDs and separate evaluation from production.
- Set an application-level step limit and a key-level spend boundary.
- Persist request IDs and tool results so retries do not repeat side effects.
- Define which status codes may be retried and which require user or operator action.
Protocol continuity matters
Tool workflows are multi-turn protocols. A client may need to return tool results, reasoning fields, or previous messages exactly as the selected route expects. Test one complete tool round trip—not just a plain prompt—before calling a model compatible. For coding agents, use the Claude Code guide; for OpenAI-shaped agents, use the SDK guide.
Fallback is a semantic event
Changing models can alter tool selection, JSON shape, context behavior, and cost. If the agent has a fallback, make it an application-owned transition: allow only evaluated pairs, record the transition, reset incompatible state when necessary, and show the chosen model in telemetry. A gateway can find an eligible route for an ID; it should not silently redefine your task contract.
Observe the whole outcome
Request latency and token cost are necessary but not sufficient. Track completed task, tool error, human correction, invalid output, and side-effect count alongside gateway data. This separates a cheap request from a cheap successful task.
Frequently asked questions
Can KeepRouter execute tools for my agent?
No. It carries supported tool-call messages; your agent runtime validates and executes tools.
Should agents automatically use any catalog model?
No. Restrict each key to models evaluated for that workflow.
Does routing replace application retries?
No. The application must still own timeouts, safe retry policy, idempotency, and task-level fallback semantics.
What should an agent team measure?
Measure task completion and tool outcomes alongside status, tokens, latency, and charge.