Sentry

Primary category: llm-observability. This page covers Sentry’s AI/agent monitoring; Sentry’s core error and performance monitoring is context, not the subject.

One-liner — The developer-incumbent route into LLM observability. If your engineers already use Sentry for errors and performance, its Agent Monitoring adds agent, tool-call and model-call traces (tokens, cost, latency, errors) to the same traces, with no new vendor.

What it does — Sentry’s SDKs auto-instrument common AI libraries and record agent runs, model calls, tool calls and handoffs as spans inside the application’s normal distributed trace. The Explore → Agents area has three views. Conversations replays multi-turn sessions grouped by conversation ID. Traces shows an agent run alongside the surrounding app work. LLM Calls compares individual requests by model, prompt, tokens, cost and latency. Dashboards cover agent executions, model cost, token usage, tool calls and recent errors. A separate MCP Servers view monitors MCP servers you operate. Its strength is correlation: an AI failure links to the frontend session replay, the backend API span and the release that shipped it, and similar failures are grouped the way Sentry groups exceptions. No evals or LLM-as-judge scoring appear in the sources reviewed. Sentry measures whether the agent broke or slowed down, not whether its answer was good. Sentry’s separate Seer product is an AI debugging agent for root cause and fixes. It is a different thing from monitoring your own AI.

Naming / provenance — Sentry began as an open-source error tracker. The company, Functional Software, Inc., was founded in 2012 in San Francisco. The AI product has been named “LLM Monitoring” (earlier beta), then “AI Agent Monitoring” (open beta announced 2025-06-26), and appears in current navigation as “Agent Tracing”. Not to be confused with Microsoft Sentinel (microsoft-sentinel), a SIEM.

Ownership & viability — independent, privately held. The last disclosed round was a $90M Series E co-led by BOND and Accel (with NEA and K5 Global) at a valuation above $3B, announced 2022-05-04, for about $217M total raised. No later round was found. The company is a mature, large developer-tools business, and AI monitoring is a feature line inside it rather than a bet-the-company product. Viability risk is low. Product risk is that AI monitoring gets less investment than the core if it doesn’t win share against Datadog and the AI-native tools.

Positioning & differentiators — platform-module: AI monitoring is a module of an incumbent developer-monitoring platform, bought because you already have Sentry.

  • Versus datadog: the same “AI traces inside the APM you already run” approach. Datadog adds built-in quality and safety evaluations and sensitive-data scanning, and is SaaS-only. Sentry is cheaper to start, developer-centric, has self-hosting under the Functional Source License, and offers no evals.
  • Versus langfuse, langsmith, arize-phoenix, braintrust, judgment-labs: those offer evals, datasets, prompt management and annotation, which Sentry doesn’t. Sentry wins on error grouping, release correlation and full-stack context.
  • Versus pydantic-logfire: both connect AI traces to app telemetry. Logfire has evals and SQL. Sentry has a much larger installed base and session replay.

Who should choose them / anti-fit — Fits a firm whose engineering teams already run Sentry and want production visibility into agents (what broke, how slow, how much it cost) at near-zero procurement friction. Anti-fit: teams that need evaluation, regression testing of prompts, or answer-quality monitoring (Sentry doesn’t do these; pair it with an eval tool). Firms standardised on Datadog. Compliance-driven buyers who need evidence-grade retention of AI interactions: Sentry is a debugging tool, not an archive.

Known weaknesses / gotchas —

  • Prompt capture is opt-in and then unscrubbed. With sendDefaultPii off, only metadata is recorded (model, tokens, tool names, timings). Turning it on captures full prompts, responses and tool inputs and outputs. Sentry’s server-side scrubbing does not cover gen_ai.input.messages, gen_ai.output.messages, gen_ai.tool.call.arguments or gen_ai.tool.call.result by default; you must add Advanced Data Scrubbing rules. For a fund, this is the single most important configuration item. Python integrations also accept include_prompts=False.
  • No evals or LLM-as-judge capability.
  • Whether every agent-monitoring view works identically on self-hosted Sentry was not confirmed. Sentry states an intent of feature parity.

Deployment & data handling — SaaS (sentry.io) or self-hosted (Docker Compose, single node, “no guarantees or dedicated support”, FSL licence converting to Apache 2.0 after two years). data_leaves_tenancy: partial: on SaaS, spans go to Sentry, and prompts and outputs go only if you enable PII capture. Self-hosted keeps everything in-house. Data-region options (US/EU) and retention periods were not confirmed on the security page reviewed. It works out-of-band through the SDK, with sampling configurable; Sentry recommends keeping complete agent runs rather than sampling all traffic.

Integrations & partnerships — Python SDK (3.x), auto-enabled: OpenAI, OpenAI Agents SDK, Anthropic, Google Gen AI, LangChain, LangGraph, Pydantic AI, Hugging Face Hub, MCP. Manual: LiteLLM, Mistral. JavaScript: Vercel AI SDK, OpenAI, Anthropic, Google GenAI, LangChain, LangGraph. MCP: Sentry monitors MCP servers you run and also offers its own hosted Sentry MCP server (mcp.sentry.dev) so coding agents can query Sentry data. Sentry was a Silver sponsor at AI Engineer New York 2026 (no session on the agenda).

Compliance & FS traction — SOC 2 Type II confirmed on Sentry’s security page. A DPA and BAA are offered (scope not reviewed). ISO 27001 was not confirmed in the sources reviewed. No FS-specific AI-monitoring references were found. Sentry’s core product is very widely used across software teams, so it may already be in a fund’s estate.

Commercial — Platform tiers: Developer free, Team $29/month ($26 annual), Business $89/month ($80 annual), Enterprise custom. Each self-serve tier includes 5M spans. “Agent tracing” is listed on all plans with no separate SKU, so AI monitoring costs whatever spans it consumes. Agents generate many spans, so watch the quota. Seer is a separate paid add-on.

Open questions

  • Formal GA status of Agent Monitoring (docs no longer label it beta, but no GA announcement was found).
  • Span overage pricing, and the typical span volume per agent run.
  • Data-region options and retention defaults for AI spans on SaaS.
  • Parity of agent and MCP monitoring on self-hosted Sentry.
  • Any roadmap toward evals or quality scoring.
  • Funding or valuation events since 2022.

Sources

History

  • [2026-10-16] Page created via wiki-create + wiki-research (AIE NYC 2026 attendee scan).