New Relic

New Relic provides a full observability stack — APM, infrastructure, logs, browser, synthetics, and alerts — under a consumption-based pricing model with a generous free tier (100GB/month ingest). For agents, the primary value is programmatic access to application telemetry: NRQL (New Relic Query Language) enables SQL-like queries over all telemetry data types. The NerdGraph API (GraphQL) is the modern programmatic interface, covering everything from data queries to account management. Agents can ship custom events and metrics via the Event API, making New Relic a viable telemetry sink for agent-generated observability data. The platform's depth means a steep integration curve, but agents focused on specific data queries can get value quickly through NRQL alone.

New Relic uses three key types: User keys (tied to a user, full NerdGraph access), Ingest keys (for data submission only — License key for APM/infra, Browser key for browser monitoring), and REST API keys (legacy, scoped to REST v2). Agents should use User keys for reading/querying and Ingest keys for writing telemetry — never mix them. Keys are created in the API Keys UI. No fine-grained permission scoping on User keys beyond account-level access — an agent with a User key can query and modify anything in the account. No OAuth for programmatic access. Key rotation requires manual creation and deletion. SAML/SSO available for console access but irrelevant for API-based agents.

Documentation at docs.newrelic.com is extensive and well-organized by product area. NRQL documentation is particularly strong with syntax reference, example queries, and function documentation. NerdGraph API Explorer provides an interactive GraphQL IDE with schema introspection. The free tier eliminates the billing-related onboarding friction — agents can start ingesting data immediately. SDK and agent documentation covers most languages. The main challenge for agent developers: the documentation surface is vast (full observability platform docs), making it hard to find the specific API patterns relevant to agent use cases. The 'Docs as Code' approach means docs are generally current. Community forums and New Relic University provide additional learning resources.

New Relic exposes two API surfaces: NerdGraph (GraphQL at api.newrelic.com/graphql) and the older REST v2 API. NerdGraph is the recommended path — it provides a unified schema covering entities, NRQL queries, dashboards, alerts, and account management. Agents can execute NRQL queries via NerdGraph's nrql() field, returning structured results. The REST v2 API covers applications, servers, alerts, and deployments but is less comprehensive and not actively expanded. Data ingest uses separate endpoints: Event API, Metric API, Log API, and Trace API, each accepting JSON payloads. Custom events are particularly useful for agents — any JSON object posted to the Event API becomes queryable via NRQL within seconds.

NerdGraph errors follow GraphQL conventions: 200 OK with errors[] array in the response body. This means HTTP status alone doesn't indicate success — agents must check the errors field. NRQL query timeouts return timeout errors for queries exceeding the 60-second limit. Rate limits on NerdGraph are account-level (25 concurrent queries per account). The Event API returns 200 for accepted events even if individual events fail validation — agents must check the response body for rejected events. REST v2 API returns standard HTTP status codes. Alert condition evaluation has a ~60-second evaluation cycle, meaning agents shouldn't expect sub-minute alert response times. Data ingest latency is typically under 5 seconds for queries over freshly ingested data.