Agent Runs

Use Vercel Agent Runs to browse eve sessions and inspect conversation traces in the project's Observability view. The tab requires enablement for your Vercel team; contact your Vercel representative if it does not appear.

Agent Runs usage is billed at Always-on Tracing rates during beta. All plans include 30-day Agent Runs retention during beta.

Enable tracing on Vercel

When eve deploy creates a new Vercel project, it configures 100% trace sampling for all environments. Existing Vercel projects need a sampling rule configured to collect traces. To enable tracing for an existing project, select your team and project, then open Settings → Tracing:

1. Select Add Sampling Rule.
2. Choose All Environments, Production, or Preview.
3. Set Rate to 100%.
4. Leave Request Path Prefix blank to sample requests on every path.
5. Select Save.

Vercel applies the first matching rule. If an existing rule matches these requests, update it to use a 100% rate; a later rule will not override it.

Tracing starts as soon as you save the rule. You can also manage sampling rules with vercel traces config. The CLI accepts rates from 1 to 100%; add a 0% rule from the dashboard.

Configure Agent Runs

Preview and production deployments export to Vercel Agent Runs by default. Omit agent/instrumentation/agent-runs.ts to keep that default. To change it, default-export agentRuns(...) from that file, or default-export disableInstrumentation() to turn off Agent Runs export.

Filter Agent Runs exports

agentRuns() accepts one exportPolicy object or an array applied in order. Each policy filters spans and attributes before the Agent Runs destination receives them:

import { agentRuns } from "eve/instrumentation/otel";

export default agentRuns({
  exportPolicy: {
    span: ({ name }) => ({ emit: name !== "internal.cache.refresh" }),
    attribute: ({ key }) => (key === "customer.id" ? { emit: false } : { emit: true }),
  },
});

Return { emit: true } from span to retain a span unchanged, or { emit: false } to omit it from Agent Runs. To retain the span while redacting content, return { redact: true } with inputs: true, outputs: true, or both. A redaction decision implies emission and requires at least one direction. A throwing span callback drops the span from Agent Runs. Return { emit: true }, { emit: false }, or { replace: true, value } from attribute to retain, remove, or change one attribute.

Redact content

The exportPolicy can further narrow what Agent Runs receives after the process-wide otel({ tracePolicy }) has admitted a trace. For example, keep spans while redacting inputs and outputs unless the session is public:

import { agentRuns } from "eve/instrumentation/otel";

export default agentRuns({
  exportPolicy: {
    span: ({ audience }) =>
      audience === "public" ? { emit: true } : { redact: true, inputs: true, outputs: true },
  },
});

Input redaction removes eve's known prompt, instruction, document, and tool-argument attributes. Output redaction removes response, reasoning, tool-result, exception, and status attributes. Redaction narrows only Agent Runs; it does not mutate spans sent to another destination.

What to read next

• OpenTelemetry: configure process-wide settings and third-party destinations.
• Vercel deployment: deploy an eve agent and inspect its runtime.
• Migrate instrumentation: replace agent/instrumentation.ts.