plugins/observability/langfuse/plugin.yaml

name: langfuse
version: "1.0.0"
description: "Optional Langfuse observability for Hermes — traces conversations, LLM calls, and tool usage. Opt-in via `hermes plugins enable observability/langfuse` or `hermes tools → Langfuse Observability`."
author: NousResearch
requires_env:
  - HERMES_LANGFUSE_PUBLIC_KEY
  - HERMES_LANGFUSE_SECRET_KEY
hooks:
  - pre_api_request
  - post_api_request
  - pre_llm_call
  - post_llm_call
  - pre_tool_call
  - post_tool_call
feat(plugins): add bundled observability/langfuse plugin Opt-in Langfuse tracing for Hermes conversations — LLM calls, tool usage, usage/cost breakdown per span. Hooks into pre/post_api_request, pre/post_llm_call, pre/post_tool_call. SDK is optional; missing SDK or credentials renders the plugin inert. Salvaged from PR #16845 by @kshitijk4poor, who wrote the plugin (~875 LOC, 6 hooks, Langfuse usage-details/cost-details normalization, read_file payload summarization). Salvage scope (why this isn't PR #16845 as-authored): - Lives at plugins/observability/langfuse/ (standalone kind, opt-in via plugins.enabled) instead of a new parallel optional-plugins/ directory. Standalone bundled plugins are already opt-in — only their plugin.yaml is scanned at startup; the Python module is not imported unless the user enables it. The premise of optional-plugins/ (avoid import cost for users who don't want it) is already solved by the existing plugin system. - Dropped the triple activation gate (plugins.enabled + plugins.langfuse.enabled + HERMES_LANGFUSE_ENABLED). The Hermes plugin system's own enable/disable is authoritative; runtime credentials gate whether the hook actually traces. - Rewrote _is_enabled() → cached _get_langfuse() with an _INIT_FAILED sentinel. The original called hermes_cli.config.load_config() from every hook invocation (full yaml parse + deep merge + env expansion on every pre/post_tool_call, potentially 100+ times per turn). The cached version reads env once and returns the cached client or None on every subsequent call with zero further work. - hermes tools → Langfuse Observability post-setup adds observability/langfuse to plugins.enabled directly (via _save_enabled_set) instead of going through an install-copy flow. Enable: hermes tools # interactive hermes plugins enable observability/langfuse # manual Required env (set by `hermes tools` or in ~/.hermes/.env): HERMES_LANGFUSE_PUBLIC_KEY HERMES_LANGFUSE_SECRET_KEY HERMES_LANGFUSE_BASE_URL # optional Co-authored-by: kshitijk4poor <kshitijk4poor@gmail.com> 2026-04-28 01:35:41 -07:00			`name: langfuse`
			`version: "1.0.0"`
			description: "Optional Langfuse observability for Hermes — traces conversations, LLM calls, and tool usage. Opt-in via `hermes plugins enable observability/langfuse` or `hermes tools → Langfuse Observability`."
			`author: NousResearch`
			`requires_env:`
			`- HERMES_LANGFUSE_PUBLIC_KEY`
			`- HERMES_LANGFUSE_SECRET_KEY`
			`hooks:`
			`- pre_api_request`
			`- post_api_request`
			`- pre_llm_call`
			`- post_llm_call`
			`- pre_tool_call`
			`- post_tool_call`