agentpprof

agentpprof turns local AI coding-agent sessions into pprof-compatible semantic profiles. It reads Codex and Claude Code JSONL history through AgentSight's agent-session crate, assigns one-word tags to sessions, prompts, and LLM calls, and writes one explicit output file.

The profiles are not CPU profiles. They are projections over agent activity: tool events, file effects, network effects, or token usage.

Install

cargo install agentpprof

From this repository:

cargo run --manifest-path agentpprof/Cargo.toml -- -o agent.pb.gz

pprof Output

Generate a semantic task profile for the current repository:

agentpprof --project-root . -o agent.pb.gz

Open it with standard Go pprof:

go tool pprof -top agent.pb.gz
go tool pprof -http=:0 agent.pb.gz

The default tasks view makes prompt tags the pprof leaf frame, so pprof -top shows where the agent spent most of its session activity semantically. Folded, SVG, and JSON outputs keep the full context-first task stack for drilldown.

Views

Use --view to choose the projection:

agentpprof -o tasks.pb.gz --view tasks
agentpprof -o system.pb.gz --view system
agentpprof -o tools.pb.gz --view tools
agentpprof -o tokens.pb.gz --view tokens
agentpprof -o files.pb.gz --view files
agentpprof -o network.pb.gz --view network

Widths mean different things by view:

• tasks: event count across tool and LLM-call activity.
• system: system-effect count, including tool category, process chain, effect, path/domain, and status frames.
• tools: compatibility alias for the system-effect projection.
• tokens: token count when reported by the agent log; otherwise bounded text estimates. Very large unsafe estimates are recorded as unknown=1 so one replayed transcript cannot dominate the profile with bogus token width.
• files: file/path effect count.
• network: network/domain effect count.

Other Formats

The default format is pprof protobuf, gzipped when the output path ends in .gz. The output extension also selects common formats:

agentpprof -o tasks.folded --view tasks
agentpprof -o tokens.svg --view tokens
agentpprof -o files.json --view files

Folded stacks are compatible with common flamegraph tooling. SVG output is a single prefix-merged flamegraph built from the folded stacks. JSON output includes redacted session summaries and the stack table. Passing --include-previews writes prompt, command, and LLM-output previews into JSON; avoid it for public artifacts unless the source sessions are already sanitized. Path frames outside the selected project root are grouped into stable external/* buckets so home-directory names are not emitted in public profiles. See ../docs/flamegraph-example/ for a flamegraph gallery and view-by-view usage examples.

Tags

The default tagger is deterministic:

agentpprof -o agent.pb.gz --tagger regex

Add project-specific deterministic rules with repeated --tag-rule arguments. Rules use KIND:TAG=REGEX, are tried in command-line order before the built-in rules, and support session, prompt, llm, or all as KIND:

agentpprof -o tasks.svg \
  --tagger regex \
  --tag-rule prompt:review='(?i)review|diff|regression' \
  --tag-rule prompt:test='(?i)cargo test|pytest|unit test'

For model-produced one-word tags, run a llama.cpp-compatible server and use:

llama-server -m /path/to/model.gguf --port 8080
agentpprof -o agent.pb.gz --tagger llm --llama-url http://127.0.0.1:8080

LLM tags are cached under the user cache directory by default, for example $XDG_CACHE_HOME/agentpprof/tags.json. Override with --cache, or pass --no-cache to avoid saving new entries.

Selecting Sessions

By default, agentpprof scans recent local Codex and Claude Code sessions that match --project-root. Those logs can contain prompts, paths, model outputs, and tool results. For repeatable private investigations, use explicit --session-file inputs.

Useful selectors:

agentpprof -o agent.pb.gz --session-file ~/.codex/sessions/.../session.jsonl
agentpprof -o agent.pb.gz --agent codex
agentpprof -o agent.pb.gz --session-id 019ec5
agentpprof -o agent.pb.gz --session-tag profile
agentpprof -o agent.pb.gz --prompt-tag review

No output directory is created unless the explicit -o/--output path contains one.

Development

cargo test --manifest-path agentpprof/Cargo.toml