# Agent Tracing > Use for agent traces by operation ID (拉线上 tracing): failed tools, arguments/results, available tools, execution location, LLM calls and context. - Skill: `lobehub/agent-tracing` (Agent Skill) - Install (CLI): `npx skillmds@latest add lobehub/agent-tracing` - Raw SKILL.md: https://api.skillmd.com/api/skills/lobehub/agent-tracing/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: lobehub (https://skillmd.com/u/lobehub) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/lobehub/agent-tracing --- # Agent Tracing CLI Guide `@lobechat/agent-tracing` is a zero-config local dev tool that records agent execution snapshots to disk and provides a CLI to inspect them. ## How It Works In `NODE_ENV=development`, `AgentRuntimeService.executeStep()` automatically records each step to `.agent-tracing/` as partial snapshots. When the operation completes, the partial is finalized into a complete `ExecutionSnapshot` JSON file. **Data flow**: executeStep loop -> build `StepPresentationData` -> write partial snapshot to disk -> on completion, finalize to `.agent-tracing/{timestamp}_{traceId}.json` **Context engine capture**: In `RuntimeExecutors.ts`, the `call_llm` executor calls `ctx.tracingContextEngine(input, output)` after `serverMessagesEngine()` processes messages. `AgentRuntimeService.executeStep` buffers the call per step and forwards it to `OperationTraceRecorder.appendStep` as the typed `contextEngine` field. CE flows through this side channel rather than the `events` array so its heavy payload (agentDocuments, systemRole, …) never enters the Redis state pipeline (LOBE-9110). ## Package Location ``` packages/agent-tracing/ src/ types.ts # ExecutionSnapshot, StepSnapshot, SnapshotSummary store/ types.ts # ISnapshotStore interface file-store.ts # FileSnapshotStore (.agent-tracing/*.json) recorder/ index.ts # appendStepToPartial(), finalizeSnapshot() viewer/ index.ts # Terminal rendering: renderSnapshot, renderStepDetail, renderMessageDetail, renderSummaryTable, renderPayload, renderPayloadTools, renderMemory cli/ index.ts # CLI entry point (#!/usr/bin/env bun) inspect.ts # Inspect command (default) partial.ts # Partial snapshot commands (list, inspect, clean) index.ts # Barrel exports ``` ## Data Storage - Completed snapshots: `.agent-tracing/{ISO-timestamp}_{traceId-short}.json` - Latest symlink: `.agent-tracing/latest.json` - In-progress partials: `.agent-tracing/_partial/{operationId}.json` - Downloaded remote snapshots: `.agent-tracing/_remote/{operationId}.json` - `FileSnapshotStore` resolves from `process.cwd()` — **run CLI from the repo root** ## Remote Traces (Production / Staging) Server deployments also upload completed snapshots to object storage (zstd-compressed; the key is stored in `agent_operations.trace_s3_key`). **Preferred: `lh trace op`.** The server resolves the key and signs the object for the caller's own scope, so a LobeHub login is the only requirement — no `TRACING_BASE_URL`, no bucket domain, and no SQL to turn a topic id into an operation id: ```bash lh trace op list --topic tpc_xxx # operations of a topic, newest first, with a TRACE column lh trace op inspect op_xxx_agt_xxx_tpc_xxx_xxxx lh trace op inspect op_xxx_agt_xxx_tpc_xxx_xxxx -T # tool injection (enabledToolIds, manifests) ``` `TRACE = —` in `list` means no snapshot was recorded for that run (it predates trace upload, or upload was off). A recorded snapshot can still 404 in storage after its retention window. Backend: the `agentTrace` lambda router (`getSnapshotUrl` / `listOperations`). Note it is `blocked` for restricted API keys, so these commands need a real session, not a scoped key. **Fallback: the standalone `agent-tracing` CLI.** It has no LobeHub session, so it builds the object URL itself and needs the bucket's public domain configured: - env var: `TRACING_BASE_URL=https:///agent-traces` - or `.agent-tracing/.env` in the repo root with the same `TRACING_BASE_URL=...` line The deployment-specific value is private to each deployment and intentionally not recorded in this repo. Find the operation id by hand first: ```sql SELECT id, trace_s3_key FROM agent_operations WHERE topic_id = 'tpc_xxx'; ``` Either way the snapshot is cached to `.agent-tracing/_remote/.json`, and every `inspect` flag works the same as for local traces. Implementation: `packages/agent-tracing/src/store/loadSnapshot.ts` (resolution order: local store → `_remote/` cache → injected `resolveDownloadUrl` → `TRACING_BASE_URL`) and `store/remote-store.ts` (URL built as `{base}/{agentId}/{topicId}/{opId}.json.zst`). Reading a compressed snapshot needs Node >= 22.15. ## Goal Trajectories A goal is one complete _goal_ execution the way an operation is one complete agent execution, so it gets the same trace format one level up: `GoalTrajectory : AdvanceSnapshot` mirrors `ExecutionSnapshot : StepSnapshot`. There is no table of advances, exactly as there is no `agent_steps` table — `goal_traces` holds one rollup row per goal plus the object key, and the detail lives in the object. The leaves join back down: an advance records the `operationId`s it put in flight (on `tick.effects[].operationId`), so `lh trace op inspect ` continues from where the goal trace stops. ```bash agent-tracing goal # list local goal trajectories agent-tracing goal goal_xxx # the run: triggers, outcomes, graph, gates, ops agent-tracing goal goal_xxx -a 3 # one advance in full, with the frontier it ranked agent-tracing goal goal_xxx -j # raw JSON ``` What each tick records is the **decision input**, not just the result: the graph it read (as a delta against the previous tick), the budget it evaluated, the responsible task's state, and every eligible work node **including the ones it passed over**. Without the losers a trace cannot answer "why not that node". **Storage** follows the operation switch, so a deployment that keeps one keeps the other: - Completed: `goal-traces/{goalId}.json.zst` - In progress: `goal-traces/_partial/{goalId}.json.zst` (an unfinished long-horizon goal is the normal thing to inspect) - Dev: `.goal-tracing/{goalId}.json` **Replay.** `replayGoalAgainstCurrentCoordinator(trajectory)` re-runs the real `decideNextMove` over the recorded inputs and reports `{advanceSeq, tickIndex, field, recorded, replayed}` wherever the current coordinator would now choose differently. This reproduces the coordinator's _decisions_ exactly; it says nothing about whether the dispatched work would have gone the same way. Implementation: `packages/agent-tracing/src/goal/`, recorded through `apps/server/src/services/goal/advanceGoal.ts` (the single funnel every advance passes through) via the `onDecision` side channel on `GoalService.tick`. ## CLI Commands All commands run from the **repo root**: ```bash # View latest trace (tree overview, `inspect` is the default command) agent-tracing agent-tracing inspect agent-tracing inspect agent-tracing inspect latest # List recent snapshots agent-tracing list agent-tracing list -l 20 # Inspect specific step (-s is short for --step) agent-tracing inspect -s 0 # View messages (-m is short for --messages) agent-tracing inspect -s 0 -m # View full content of a specific message (by index shown in -m output) agent-tracing inspect -s 0 --msg 2 agent-tracing inspect -s 0 --msg-input 1 # View tool call/result details (-t is short for --tools) agent-tracing inspect -s 1 -t # View raw events (-e is short for --events) agent-tracing inspect -s 0 -e # View runtime context (-c is short for --context) agent-tracing inspect -s 0 -c # View context engine input overview (-p is short for --payload) agent-tracing inspect -p agent-tracing inspect -s 0 -p # View available tools in payload (-T is short for --payload-tools) agent-tracing inspect -T agent-tracing inspect -s 0 -T # View user memory (-M is short for --memory) agent-tracing inspect -M agent-tracing inspect -s 0 -M # Raw JSON output (-j is short for --json) agent-tracing inspect -j agent-tracing inspect -s 0 -j # List in-progress partial snapshots agent-tracing partial list # Inspect a partial (use `inspect` directly — all flags work with partial IDs) agent-tracing inspect agent-tracing inspect -T agent-tracing inspect -p # Clean up stale partial snapshots agent-tracing partial clean # Map the context window composition of every LLM call (cm / map are aliases) agent-tracing ctx-map agent-tracing ctx-map agent-tracing ctx-map --html # standalone report under .agent-tracing/_reports/ agent-tracing ctx-map --html out.html # Re-issue a recorded LLM call against other models (see "replay" below) agent-tracing replay agent-tracing replay -s 4 -m openai/gpt-5,anthropic/claude-sonnet-5 agent-tracing replay --all-steps ``` ## replay — Re-issue a Frozen Call A snapshot already freezes everything one LLM call saw: `steps[].contextEngine.output` is the exact message array sent to the model, `context.payload.tools` the toolset it could reach. `replay` sends that frozen payload back out with only the model swapped, so a difference in output is attributable to the model rather than to context assembly. If every model fails the same payload, the context is at fault; if some pass, it is model selection. Available from both CLIs — `agent-tracing replay` (reads `LOBEHUB_JWT`) and `lh trace op replay` (uses the `lh login` session). Both need credentials because the call goes out through the LobeHub chat route. ```bash # One call: defaults to the last call_llm step and the model the op ran on lh trace op replay lh trace op replay -s 4 -m openai/gpt-5,anthropic/claude-sonnet-5 lh trace op replay --judge "answers with a concrete file path" # Every call of the operation lh trace op replay --all-steps lh trace op replay --all-steps --concurrency 8 ``` `--all-steps` answers the question the whole feature exists for: **take a run that succeeded, put another model on it, and see whether that model also gets the job done.** It ends in a PASS / FAIL verdict from an llm-rubric judge comparing the replayed outcome against the recorded one; pass `--judge ""` to define success yourself instead of using the default rubric. The judge scores the **outcome, not the route**. A model that solved the same problem by calling different tools has passed. The per-call tool comparison (`toolSignature`) is reported underneath as supporting evidence — where the run took another path — and never decides pass / fail. A final call that never reached the model is a FAIL, not a missing verdict. Each call is replayed independently, against the payload the harness actually built for it, so a different answer at call 2 cannot contaminate call 4, a call that fails to reach the provider costs only itself, and the calls go out concurrently (4 at a time by default). Chaining the nodes — feeding each replayed output into the next — was built and then removed. A trace cannot regenerate tool output, only hand back what was recorded, so the moment the model deviates there is no ground truth left; the run then measures nothing while still looking like it succeeded. Independent replay is the design, not a fallback. Known limitation: **sampling parameters are not recorded.** The recorder stores the runtime step context under `context.payload`, not the provider request body, so temperature, `top_p`, `max_tokens`, penalties and reasoning config are absent from every trace written so far. Replays use the server's current defaults for those. Model-to-model comparisons stay valid (every target gets the same request); comparisons against the recorded output do not, for an operation that ran with non-default settings. `--temperature` / `--max-tokens` override explicitly. The CLI prints a `note` line whenever a replay is running without recorded parameters. ## ctx-map — Context Window Composition `ctx-map` renders one row per `call_llm` step: the messages that call sent to the model, split into typed segments (system / injected block / user / reasoning / tool call / tool result) with width proportional to tokens, laid against the model's context window. The second axis is what `ctx-lint` cannot show: each row is diffed against the previous call, so the longest identical **message prefix** — the part a provider's prefix cache can reuse — is marked, along with the first message that mutated and the tokens re-processed behind it. A small injected block carrying a relative timestamp (`1m ago` → `now`) invalidates every token after it, which shows up as a break marker early in the row. Reading a row: - **Block colors** encode role directly: orange system, green user, blue assistant, gray tool. Assistant reasoning, content, and tool calls use different steps of the same blue scale; framework-injected blocks use a lighter orange than the system prompt. Every value is a step index into a LobeHub scale vendored in `viewer/contextMapScales.ts`, with assignments in `viewer/contextMapPalette.ts`. The HTML report ships both themes and follows the system theme. - **Neutral message frames** group segments that belong to the same payload message. Every role uses the same frame color: the outline communicates structure only, while the block fill carries role and subtype semantics. The original framed layout uses padding inside each message and a small track gap between messages, keeping each payload message visually distinct. - **Fill** says whether the provider reused it: shaded `▓` (HTML: 60%-opaque hatch) was served from the prefix cache; solid `█` (HTML: flat) was re-processed by the model. - **The line under the track** is the cache ledger — a bracket / green band spanning exactly the cached prefix, then the break marker (`▲` in the terminal, a red rule through the track in HTML) at the column where reuse stopped, with the reason and the re-processed tokens. | Flag | Short | Description | | --------------- | ----- | ---------------------------------------------------------- | | `--html [path]` | | Standalone HTML report (hover a segment for its content) | | `--width ` | `-w` | Track width in terminal columns | | `--window ` | | Override the model context window used as the track | | `--full-window` | | Always scale to the full window, never to the largest call | | `--json` | `-j` | Per-call segments + cache stats | The track scales to the context window; when the window dwarfs the payloads (a 50k payload on a 1M window) it falls back to the largest call so the composition stays readable, and the header says which basis is in use. Analysis lives in `analysis/contextMap.ts` and is exported as `buildContextMap()` for downstream corpus work. ## Inspect Flag Reference | Flag | Short | Description | Default Step | | ----------------- | ----- | ------------------------------------------------------------------------------------------------- | ------------ | | `--step ` | `-s` | Target a specific step | — | | `--messages` | `-m` | Messages context (CE input → params → LLM payload) | — | | `--tools` | `-t` | Tool calls & results (what agent invoked) | — | | `--events` | `-e` | Raw events (llm\_start, llm\_result, etc.) | — | | `--context` | `-c` | Runtime context & payload (raw) | — | | `--system-role` | `-r` | Full system role content | 0 | | `--env` | | Environment context | 0 | | `--payload` | `-p` | Context engine input overview (model, knowledge, tools summary, memory summary, platform context) | 0 | | `--payload-tools` | `-T` | Available tools detail (plugin manifests + LLM function definitions) | 0 | | `--memory` | `-M` | Full user memory (persona, identity, contexts, preferences, experiences) | 0 | | `--diff ` | `-d` | Diff against step N (use with `-r` or `--env`) | — | | `--msg ` | | Full content of message N from Final LLM Payload | — | | `--msg-input ` | | Full content of message N from Context Engine Input | — | | `--json` | `-j` | Output as JSON (combinable with any flag above) | — | Flags marked "Default Step: 0" auto-select step 0 if `--step` is not provided. All flags support `latest` or omitted traceId. ## Typical Debug Workflow ```bash # 1. Trigger an agent operation in the dev UI # 2. See the overview agent-tracing inspect # 3. List all traces, get traceId agent-tracing list # 4. Quick overview of what was fed into context engine agent-tracing inspect -p # 5. Inspect a specific step's messages to see what was sent to the LLM agent-tracing inspect TRACE_ID -s 0 -m # 6. Drill into a truncated message for full content agent-tracing inspect TRACE_ID -s 0 --msg 2 # 7. Check available tools vs actual tool calls agent-tracing inspect -T # available tools agent-tracing inspect -s 1 -t # actual tool calls & results # 8. Inspect user memory injected into the conversation agent-tracing inspect -M # 9. Diff system role between steps (multi-step agents) agent-tracing inspect TRACE_ID -r -d 2 ``` ## Key Types ```typescript interface ExecutionSnapshot { traceId: string; operationId: string; model?: string; provider?: string; startedAt: number; completedAt?: number; completionReason?: 'done' | 'error' | 'interrupted' | 'max_steps' | 'cost_limit' | 'waiting_for_human'; totalSteps: number; totalTokens: number; totalCost: number; error?: { type: string; message: string }; steps: StepSnapshot[]; } interface StepSnapshot { stepIndex: number; stepType: 'call_llm' | 'call_tool'; executionTimeMs: number; content?: string; // LLM output reasoning?: string; // Reasoning/thinking inputTokens?: number; outputTokens?: number; toolsCalling?: Array<{ apiName: string; identifier: string; arguments?: string }>; toolsResult?: Array<{ apiName: string; identifier: string; isSuccess?: boolean; output?: string; }>; messages?: any[]; // DB messages before step context?: { phase: string; payload?: unknown; stepContext?: unknown }; events?: Array<{ type: string; [key: string]: unknown }>; contextEngine?: { input?: unknown; // contextEngineInput minus messages + toolsConfig (reconstructible from baseline) output?: unknown; // processed messages array (final LLM payload) }; } ``` ## --messages Output Structure When using `--messages`, the output shows three sections (if context engine data is available): 1. **Context Engine Input** — DB messages passed to the engine, with `[0]`, `[1]`, ... indices. Use `--msg-input N` to view full content. 2. **Context Engine Params** — systemRole, model, provider, knowledge, tools, userMemory, etc. 3. **Final LLM Payload** — Processed messages after context engine (system date injection, user memory, history truncation, etc.), with `[0]`, `[1]`, ... indices. Use `--msg N` to view full content. ## Integration Points - **Recording**: `apps/server/src/services/agentRuntime/AgentRuntimeService.ts` — in the `executeStep()` method, after building `stepPresentationData`, writes partial snapshot in dev mode - **Context engine capture**: `apps/server/src/modules/AgentRuntime/RuntimeExecutors.ts` — in `call_llm` executor, after `serverMessagesEngine()` returns, calls `ctx.tracingContextEngine(input, output)`. `AgentRuntimeService.executeStep` buffers it per step and passes it to `traceRecorder.appendStep` as the typed `contextEngine` field (kept off the `events` array to stay out of Redis state). - **Store**: `FileSnapshotStore` reads/writes to `.agent-tracing/` relative to `process.cwd()`