Config schema

Every key of the plugin's config file. The plugin reads the first file it finds: the path in HERMES_OTEL_CONFIG, then ~/.hermes/hermes_otel.yaml, then the legacy ~/.hermes/plugins/hermes_otel/config.yaml (which a reinstall deletes). See config.yaml for a guided tour.

The field table below is generated from HermesOtelConfig by scripts/gen_config_docs.py, and a test fails if it drifts from the code.

A numeric field's Bounds are checked at load (#487). A value outside them, in the yaml or an env override, logs a warning naming the field, and the default is used instead. An export batch size larger than its queue size is lowered to the queue size. (Before 1.30.1 such a value reached the OpenTelemetry SDK, which raised during startup, so every backend logged traces init failed and nothing was exported.)

Top level

Field	Type	Default	Description
enabled	bool	true	Master switch; false registers no hooks and exports nothing
sample_rate	float | null	null	Parent-based trace-ID ratio 0.0–1.0; null = AlwaysOn (no sampling). Bounds: 0.0–1.0
root_span_ttl_ms	int	600000	Orphan-sweep TTL: a turn root older than this with no end hook is closed. Bounds: ≥ 1
subagent_span_ttl_ms	int	86400000	Delegation-span TTL: a subagent.* span whose subagent_stop never arrives is closed after this (it outlives the parent's turn by design). Bounds: ≥ 1
flush_interval_ms	int	60000	Metrics export cadence (PeriodicExportingMetricReader). Bounds: ≥ 1
preview_max_chars	int	1200	Cap on preview strings (tool args/results, user message, assistant response). Bounds: ≥ 1
capture_previews	bool	true	Deprecated spelling of content_capture: off (when false); kept consistent with content_capture
tool_input_preview_max_chars	int | null	null	Per-category cap for tool args previews; null = preview_max_chars. Bounds: ≥ 1
tool_output_preview_max_chars	int | null	null	Per-category cap for tool result previews; null = preview_max_chars. Bounds: ≥ 1
llm_input_preview_max_chars	int | null	null	Per-category cap for LLM input previews; null = preview_max_chars. Bounds: ≥ 1
llm_output_preview_max_chars	int | null	null	Per-category cap for LLM output previews; null = preview_max_chars. Bounds: ≥ 1
headers	map	(unset)	Extra HTTP headers on every OTLP request; per-backend headers: are merged onto these
global_tags	map	(unset)	Deprecated: merged into resource_attributes at load (which wins on a key conflict)
resource_attributes	map	(unset)	Merged into the Resource on top of the defaults service.name=hermes-agent, service.instance.id (per-process UUID), service.version, process.pid, hermes.profile
common_attributes	map	(unset)	Stamped on every span, log record and metric point (not the Resource), for backends that do not index resource attributes per signal; scalar values, keys of at most 64 chars outside hermes. / gen_ai. / service.. A plugin attribute of the same name wins; changing a value starts new metric series
project_name	string | null	(unset)	openinference.project.name on the Resource (Phoenix project); overrides OTEL_PROJECT_NAME
service_name_from_profile	bool	false	A named profile exports as service.name=<profile> with service.namespace=hermes-agent; the default profile stays hermes-agent. resource_attributes.service.name still wins
span_batch_max_queue_size	int	2048	Max buffered spans per backend before drops. Bounds: ≥ 1
span_batch_schedule_delay_ms	int	1000	BatchSpanProcessor worker wake-up cadence. Bounds: ≥ 1
span_batch_max_export_batch_size	int | null	null	Max spans per OTLP POST; null = 512, or 64 when content_capture is full. Bounds: ≥ 1
span_batch_export_timeout_ms	int	30000	Per-export HTTP timeout. Bounds: ≥ 1
force_flush_on_session_end	bool	true	Flush every backend's span queue at the end of each turn, from a background thread (500 ms per backend, coalesced)
force_flush_wait_ms	int	1500	How long the turn waits for that background flush (spans, then metrics and logs on a second thread) before returning to Hermes; a one-shot run exits right after, so this bounds what it exports; 0 = do not wait. Bounds: ≥ 0
capture_conversation_history	bool	false	Attach the full message JSON to llm.* spans
conversation_history_max_chars	int	20000	JSON cap when conversation capture is on. Bounds: ≥ 1
content_capture	string	"full"	full (default): complete prompt and response on every api.* span · preview: clipped previews only · off: no content, metadata only; see Conversation capture
capture_full_prompts	bool	true	Deprecated: derived from content_capture; false keeps prompts as previews in full mode
capture_full_responses	bool	true	Deprecated: derived from content_capture; false keeps responses as previews in full mode
capture_sender_id	bool	false	Gateway sessions add hermes.sender.id and user.id (platform:sender)
capture_logs	bool	false	Attach an OTel LoggingHandler to Python logging; see OTel logs
log_level	string	"INFO"	Handler level: DEBUG / INFO / WARNING / ERROR / CRITICAL
log_attach_logger	string | null	(unset)	Logger to attach to; null = root, hermes_otel = the plugin only
log_exclude_loggers	list of strings (env: comma-separated)	[opentelemetry, urllib3, httpx, httpcore, requests, openai, asyncio, hpack, grpc, websockets, charset_normalizer, markdown_it]	Logger-name prefixes never forwarded (loop guard + Hermes' noisy third-party loggers); logs.exclude_loggers
log_logger_levels	map	(unset)	Per-logger minimum level, e.g. {gateway.config: WARNING}; logs.logger_levels
log_only_in_turn	bool	false	Drop records the plugin cannot attribute to a session; logs.only_in_turn
log_max_attribute_length	int	4096	Longest exported string attribute on a log record (characters); logs.max_attribute_length. Bounds: ≥ 1
log_batch_schedule_delay_ms	int	1000	Log batch processor: export every N ms; logs.batch.schedule_delay_ms. Bounds: ≥ 1
log_batch_max_queue_size	int	2048	Log batch processor: queued records before drops; logs.batch.max_queue_size. Bounds: ≥ 1
log_batch_max_export_batch_size	int	512	Log batch processor: records per export request; logs.batch.max_export_batch_size. Bounds: ≥ 1
log_batch_export_timeout_ms	int	30000	Log batch processor: per-export timeout; logs.batch.export_timeout_ms. Bounds: ≥ 1
log_live_min_level	string	"INFO"	Floor for the dashboard's live Logs tab (INFO default; the OTLP path keeps log_level); logs.live_min_level
log_events	bool	false	Emit structured hermes.* / GenAI events (log records with an event name) from the hooks; logs.events.enabled
log_events_content	string	"inherit"	Content on events: inherit (follow content_capture) / full / preview / off; logs.events.content
emit_genai_metrics	bool	true	Also emit the OTel GenAI spec metrics (gen_ai.client.*, gen_ai.agent.*)
metrics_temporality	string | null	(unset)	Metric temporality for OTLP export: cumulative (Prometheus family) or delta (Datadog, New Relic, Logfire); unset = SDK default; a backend entry's own value wins
metrics_histogram	string	"explicit"	Histogram aggregation: explicit (spec bucket boundaries) or exponential (base-2, for backends that accept it)
metrics_label_limit	int	100	Distinct values a metric label such as model may take per process before the rest fold into other (0 = no cap). Bounds: ≥ 0
metric_name_compat	string	"off"	off · claude_code · both — export session count, token usage, cost and active time under Claude Code's metric names, units and labels (claude_code.*) instead of (claude_code) or beside (both) the hermes.* twins, so dashboards built for Claude Code read Hermes; see Claude Code dashboards
metric_name_compat_session_id	bool	false	Also put session.id on the claude_code.* instruments, as Claude Code does by default (per-session panels need it; one series per session)
disable_metrics	list of strings (env: comma-separated)	[]	Instruments never created, recorded or exported: hook keys (tool_duration), dotted (tool.duration) or OTLP names (hermes.tool.duration), or all; an unknown name warns at load. See Disabling metrics and span families
disable_spans	list of strings (env: comma-separated)	[]	Span families never recorded (tool, api, llm, approval, skill, subagent, kanban, auxiliary, human_input); a child of a disabled span parents to the nearest recording ancestor. all is refused (use a backend's traces: false)
skill_spans	bool	true	Open a skill.<name> span on each successful skill load, closed at turn end
remote_parent	bool	true	Parent the turn root under the span named by HERMES_OTEL_TRACEPARENT (+ HERMES_OTEL_TRACESTATE) when an outer process exported them; false ignores the variables. The kanban worker hand-off (TRACEPARENT) is separate
probe_backends	bool	true	At init, open one TCP connection to each backend endpoint on a background thread and log reachable / unreachable per backend; once, never periodic, no bytes sent, exports never wait for it
discovery_prompt	bool	false	Register a system-prompt section advertising hermes_otel:observability (changes what the model sees every turn; opt-in)
dashboard_live	bool	true	Keep recent spans/metrics/logs in $HERMES_HOME/hermes_otel_live.db for the dashboard's Live mode
dashboard_live_max_spans	int	1000	Rows kept per kind (spans, metrics, logs) in the live store. Bounds: ≥ 1
dashboard_live_retention_hours	float	168.0	Rows older than this are dropped from the live store (0 = only the row cap applies). Bounds: ≥ 0.0
host_metrics	bool	false	Sample CPU/GPU and emit process.* / system.* / hw.* metrics; see Host & GPU metrics
host_metrics_gpu	string	"auto"	auto · amd · nvidia · off — which GPU SDK to probe
host_metrics_interval_ms	int	1000	Host sampling cadence (floor 50 ms). Bounds: ≥ 1
suppress_mcp_ping_spans	bool	true	Drop successful MCP keepalive ping spans before export
backends	list	(unset)	Multi-backend fan-out list; see the backends[] section

When backends: holds at least one usable entry, single-backend env-var detection is skipped. If every entry is dropped while loading (an entry with no type, for example), env-var detection runs after all.

backends[] entries

Shared fields (all optional unless noted):

Field	Type	Description
type	string	Required. One of: phoenix, langfuse, signoz, jaeger, zipkin, greptime, clickstack, victoria, aspire, gigapipe, agenta, tempo, otlp, lgtm, uptrace, openobserve, parseable, honeycomb, weave, langsmith, elastic, openlit, mlflow, opik, laminar, langwatch, latitude (see backends). Aliases: hyperdx (clickstack), victoriatraces (victoria), qryn (gigapipe), openobserver (openobserve)
name	string	Friendly name shown in logs (default: type)
endpoint	string	Full HTTP traces URL, or gRPC host:port / https://host:port origin (no signal path). Required, either here or in the type's OTEL_<TYPE>_ENDPOINT variable, except for the types that have a default: langfuse and weave (built from base_url), honeycomb, agenta and langsmith (built from region), and opik, laminar, langwatch and latitude (their cloud hosts)
metrics_endpoint, logs_endpoint	string	The full URL (gRPC: the target) for that signal, used as written instead of the one derived from endpoint; victoria reads them as its store origins (below)
protocol	string	http/protobuf (default), or grpc for a generic type: otlp entry. Applies to traces, metrics and logs; headers_helper needs http/protobuf
insecure	bool	gRPC only: true selects plaintext, false forces TLS. Unset: SDK INSECURE env vars, then the endpoint scheme (http is plaintext; HTTPS / bare targets are TLS). HTTPS cannot be combined with true
certificate_file	string	PEM CA bundle for server verification; unset uses SDK CERTIFICATE env vars or system trust
client_certificate_file	string	PEM client certificate chain for mTLS; gRPC requires client_key_file too
client_key_file	string	PEM client private key for mTLS; requires client_certificate_file
ui_url	string	Where the backend's web UI is, for the dashboard's Settings tab to link its card to. Optional. Without it the tab works the link out from the type: the endpoint origin for types whose UI is served there, query_port for Jaeger and SigNoz, the known SaaS UI for Honeycomb, W&B Weave and LangSmith, and no link for otlp and elastic. It never guesses a port
traces	bool	Override trace-export default (true). Set false for dashboard/query-only backends that should not receive span exports. trace is accepted as an alias.
metrics	bool	Override metrics-export default for this backend
metrics_temporality	string	cumulative or delta for this backend's metric reader; overrides the top-level default and the type preset (signoz, uptrace, elastic → delta)
root_usage	bool	Send the turn's token roll-up (gen_ai.usage.* / llm.token_count.* on the agent / cron root) to this backend. Preset false for opik and langwatch, which sum usage over every span and would double the trace total (#327); true everywhere else. Only this entry's exporter is affected: the span is rebuilt without those keys on its way out, the api.* spans and hermes.cost.* stay
logs	bool or map	Override the logs-export default. On for signoz, greptime, clickstack, victoria (with logs_endpoint), aspire, gigapipe, uptrace, openobserve, parseable, honeycomb, elastic, openlit, laminar, langwatch, lgtm and otlp; off for the rest. A mapping (level, exclude_loggers, logger_levels, only_in_turn, events) turns logs on with per-backend overrides
headers	map	Per-backend HTTP headers / gRPC metadata (merged onto top-level headers; gRPC names are lowercased)
headers_helper	string	A command (argv string, no shell) whose stdout, a JSON object or Name=value lines, mints headers merged over headers and the type's own auth header on every signal of this entry; on a 401/403 it is re-run once and the batch retried once (short-lived credentials, #483)
headers_helper_timeout_ms	int	How long one helper run may take; default 5000

TLS paths support ~ and ${VAR_NAME}. Explicit paths override signal-specific SDK environment variables, then global variables. Invalid files or TLS credentials on a plaintext endpoint are rejected. See gRPC and TLS for examples, environment variables and certificate rotation.

Type-specific fields

Keys marked "Dashboard read path" are read only by the dashboard tab and the query tool, never by the exporter. Where a service_name defaults to the plugin's resource_attributes.service.name, else hermes-agent, the named profile comes in between when service_name_from_profile: true.

phoenix

Field	Type	Description
endpoint	string	Required. e.g. http://localhost:6006/v1/traces. Traces only (Phoenix rejects /v1/metrics)

langfuse

Field	Type	Description
public_key	string	Langfuse public key (inline; discouraged)
public_key_env	string	Env var name holding the public key
secret_key	string	Langfuse secret key (inline; discouraged)
secret_key_env	string	Env var name holding the secret key
base_url	string	Langfuse base URL; the plugin appends /api/public/otel/v1/traces. Default: LANGFUSE_BASE_URL, else https://cloud.langfuse.com
query_api	string	Dashboard read path: v3 (trace endpoints), v4 (events_only: v2 observations + v2 metrics), or auto (default: probed once per query URL)
endpoint	string	Override; skips base_url construction

Both keys are required (an entry with one is skipped with a warning). The plugin builds the Basic Auth header from them.

signoz

Field	Type	Description
endpoint	string	OTLP endpoint (self-host: http://localhost:4328/v1/traces; cloud: https://ingest.<region>.signoz.cloud:443/v1/traces)
ingestion_key	string	SigNoz Cloud ingestion key (inline; discouraged)
ingestion_key_env	string	Env var name holding the ingestion key
query_port	int	Dashboard read path: the SigNoz UI/API port (default 3301; 443 behind an HTTPS ingress)
api_key / api_key_env	string	Dashboard read path: a SigNoz API key, sent as SIGNOZ-API-KEY (current SigNoz issues them from a service account). Ingestion never needs it

When an ingestion key is set, the plugin adds the signoz-ingestion-key header.

jaeger

Field	Type	Description
endpoint	string	Required. e.g. http://localhost:4318/v1/traces. Traces only (metrics/logs off)
query_port	int	Dashboard read path: the Jaeger UI/query port. Default: the endpoint's own port, else 16686, so with an OTLP endpoint on 4318 set this to 16686
query_api	string	Dashboard read path: v1 (classic /api/traces), v3 (Jaeger v2's /api/v3), or auto (default: probed once per query URL)
service_name	string	Dashboard read path: the service every search names (default: the plugin's resource_attributes.service.name, else hermes-agent)

zipkin

Field	Type	Description
endpoint	string	Required. The Zipkin origin, e.g. http://localhost:9411 (a /v1/traces suffix is added; /v1/metrics or /v1/logs is rewritten). Also via OTEL_ZIPKIN_ENDPOINT. Traces only (metrics/logs off). Needs the zipkin-otel image: stock Zipkin has no OTLP endpoint
query_port	int	Dashboard read path: the port serving API v2 and the UI (default: the endpoint's port, else 9411)
service_name	string	Dashboard read path: the service every search names (default: the plugin's resource_attributes.service.name, else hermes-agent)
api_key / api_key_env	string	Dashboard read path: a bearer token for an authenticating proxy in front of Zipkin; none upstream

See Zipkin.

greptime

Field	Type	Description
endpoint	string	Required. The GreptimeDB HTTP origin, e.g. http://localhost:4398 (bundled stack) or http://<host>:4000; a /v1/otlp prefix or any /v1/otlp/v1/<signal> URL also works. Also via OTEL_GREPTIME_ENDPOINT. Traces carry X-Greptime-Pipeline-Name: greptime_trace_v1; metrics and logs do not
db / db_env	string	Optional database (X-Greptime-DB-Name on every signal; fallback OTEL_GREPTIME_DB; server default public)
user / user_env, password / password_env	string	Optional Basic auth for a server with a user provider (fallbacks OTEL_GREPTIME_USER / OTEL_GREPTIME_PASSWORD); omitted when either is missing
metrics / logs / traces	bool	Per-signal toggles; all three default on
query_port	int	Dashboard read path: the HTTP port (default: the endpoint's port, else 4000)
query_path	string	Dashboard read path: where the Jaeger-compatible API hangs (default /v1/jaeger)
search_fetch	int	Dashboard read path: traces asked for per search before the page is cut here (default 500; GreptimeDB's limit keeps arbitrary traces, not the newest)
logs_table	string	Dashboard read path: the OTLP logs table (default opentelemetry_logs)
metrics_match	string	Dashboard read path: a PromQL series selector narrowing the metric list (default: the plugin's namespaces)
service_name	string	Dashboard read path: the service every trace search names (default: the plugin's resource_attributes.service.name, else hermes-agent)

See GreptimeDB.

clickstack

Field	Type	Description
endpoint	string	Required. The ClickStack Collector's OTLP/HTTP base, e.g. http://localhost:4408 (bundled stack) or http://<host>:4318. Also via OTEL_CLICKSTACK_ENDPOINT. A base URL gets /v1/traces; the other two signals are derived
api_key / api_key_env	string	Required. The team's ingestion API key, sent as a bare authorization: <key> header (fallbacks OTEL_CLICKSTACK_API_KEY, HYPERDX_API_KEY); a missing key skips the entry
metrics / logs / traces	bool	Per-signal toggles; all three default on
query_port	int	Dashboard read path: the ClickHouse HTTP port (default 8123; 8124 on the bundled stack)
user / user_env, password / password_env	string	Dashboard read path: ClickHouse credentials (api / api on the all-in-one image; its default user only answers from inside the container)
database	string	Dashboard read path: the ClickHouse database (default default)
traces_table, logs_table	string	Dashboard read path: table names (defaults otel_traces, otel_logs)
metrics_match	string	Dashboard read path: a regular expression on metric names (default: the plugin's namespaces)
ui_url	string	Dashboard read path: the HyperDX UI origin for the "open in" search link
service_name	string	Dashboard read path: the service every trace search names (default: the plugin's resource_attributes.service.name, else hermes-agent)

See ClickStack.

victoria

Field	Type	Description
endpoint	string	Required. VictoriaTraces origin or ingest URL (http://localhost:10428 → /insert/opentelemetry/v1/traces). Also via OTEL_VICTORIA_ENDPOINT
metrics_endpoint	string	VictoriaMetrics origin or ingest URL (http://localhost:8428 → /opentelemetry/v1/metrics); metrics are off without it. Also via OTEL_VICTORIA_METRICS_ENDPOINT
logs_endpoint	string	VictoriaLogs origin or ingest URL (http://localhost:9428 → /insert/opentelemetry/v1/logs); logs are off without it. Also via OTEL_VICTORIA_LOGS_ENDPOINT
user / user_env, password / password_env	string	Optional Basic auth sent to all three stores (fallbacks OTEL_VICTORIA_USER / OTEL_VICTORIA_PASSWORD)
headers	map	Extra headers on every signal; a VL-Stream-Fields entry replaces the default service.name the type sends on logs
metrics / logs / traces	bool	Per-signal toggles; an explicit metrics: true / logs: true needs the matching store named, else the entry is skipped with a hint
prometheus_url, logs_url	string	Dashboard read path: the VictoriaMetrics and VictoriaLogs origins (default: metrics_endpoint / logs_endpoint)
query_port, query_path, search_fetch	int / string / int	Dashboard read path: VictoriaTraces' port (default the endpoint's, else 10428), the Jaeger-compatible API prefix (default /select/jaeger) and the traces fetched per search before the page is cut (default 500)
metrics_match, service_name	string	Dashboard read path: a PromQL series selector for the metric list; the service every trace search names

See VictoriaMetrics family.

aspire

Field	Type	Description
endpoint	string	Required. The Aspire Dashboard's OTLP/HTTP base, e.g. http://localhost:4418 (bundled stack) or http://<host>:18890. Also via OTEL_ASPIRE_ENDPOINT. A base URL gets /v1/traces; the other two signals are derived
api_key / api_key_env	string	Optional OTLP API key → x-otlp-api-key (fallback OTEL_ASPIRE_API_KEY); only with DASHBOARD__OTLP__AUTHMODE=ApiKey. The dashboard adapter sends the same value as x-api-key
metrics / logs / traces	bool	Per-signal toggles; all three default on
query_port	int	Dashboard read path: the UI port serving /api/telemetry/* (default 18888)
ui_url	string	Dashboard read path: the UI origin for the /traces/detail/{traceId} link (default: the query URL)
search_fetch, logs_fetch	int	Dashboard read path: traces and log records fetched per query before the window and filters are applied client-side (defaults 500, 5000)
service_name	string	Dashboard read path: the service whose Aspire resources (one per Hermes process, resolved through /api/telemetry/resources) the API is asked for (default: the plugin's resource_attributes.service.name, else hermes-agent)

See Aspire Dashboard.

gigapipe

Field	Type	Description
endpoint	string	Required. Gigapipe's origin, e.g. http://localhost:3110 (bundled stack) or http://<host>:3100; a base URL gets /v1/traces, the other two signals are derived. Also via OTEL_GIGAPIPE_ENDPOINT
user / user_env, password / password_env	string	Optional Basic auth (fallbacks OTEL_GIGAPIPE_USER / OTEL_GIGAPIPE_PASSWORD); omitted when either is missing
metrics / logs / traces	bool	Per-signal toggles; all three default on
query_port, prometheus_url, loki_url	int / string	Dashboard read path: all default to the endpoint's origin (one port serves the Tempo, Prometheus and Loki APIs); loki_url: off disables the Logs tab
search_fetch, metrics_match, loki_selector, ui_url	as for lgtm	Dashboard read path

See Gigapipe.

agenta

Field	Type	Description
endpoint	string	Agenta's origin for a self-hosted stack, e.g. http://localhost:3060 (an origin, /api, /api/otlp or the full /api/otlp/v1/traces URL). Also via OTEL_AGENTA_ENDPOINT / AGENTA_HOST. Unset: Agenta Cloud for region
region	string	us (default) or eu: the cloud host when endpoint is unset
api_key / api_key_env	string	Required. A project API key → Authorization: ApiKey <key> (fallbacks OTEL_AGENTA_API_KEY, AGENTA_API_KEY); a missing key skips the entry. The dashboard adapter reads with the same key
metrics / logs / traces	bool	Per-signal toggles; metrics and logs default off (Agenta mounts only the traces route)
ui_url	string	Dashboard read path: the project's observability page for an "open in" link (the adapter cannot derive the workspace and project ids)
service_name	string	Dashboard read path: the service shown on cards and in the detail's resource (Agenta stores no resource attributes)

See Agenta.

tempo

Field	Type	Description
endpoint	string	Required. Traces only (metrics/logs off); use type: lgtm for the all-in-one Grafana container
query_port	int	Dashboard read path: Tempo's query API port (default 3200)
prometheus_url / loki_url	string	Optional. Naming them gives a Tempo entry the same dashboard metrics/logs as lgtm
search_fetch	int	Dashboard read path: traces asked of Tempo per search page before the newest limit are kept (default 500; Tempo's own limit is not newest-first). Also on lgtm entries

otlp

Field	Type	Description
endpoint	string	Required. OTLP traces endpoint
metrics	bool	Default: true; set false for traces-only collectors
logs	bool	Default: true; set false if the collector doesn't accept /v1/logs

Use headers: for auth (${VAR} interpolation supported).

lgtm

Alias over otlp with a dedicated display name and all signals on by default. See Grafana LGTM.

Field	Type	Description
endpoint	string	Required. OTLP traces endpoint — http://localhost:4318/v1/traces for the bundled docker-compose/lgtm/docker-compose.yaml
metrics	bool	Default: true
logs	bool	Default: true
query_port	int	Dashboard read path: Tempo's query API port (default 3200)
prometheus_url	string	Dashboard metrics. Default: port 9090 on the Tempo host (the otel-lgtm layout); off disables
loki_url	string	Dashboard logs. Default: port 3100 on the Tempo host; off disables (e.g. a Loki without OTLP)
metrics_match	string	Optional Prometheus series selector for the instrument list, e.g. {__name__=~"hermes_.*"} on a shared Prometheus
loki_selector	string	Optional LogQL stream selector the log filters are applied to (default {service_name=~".+"})

Use type: lgtm (not type: tempo) when pointing at the grafana/otel-lgtm container — tempo is traces-only and would disable the logs/metrics fan-out.

uptrace

Field	Type	Description
endpoint	string	Required. OTLP traces endpoint (self-host: http://localhost:14318/v1/traces). Also via OTEL_UPTRACE_ENDPOINT
dsn	string	Uptrace DSN, sent as the uptrace-dsn header on every export (inline; discouraged)
dsn_env	string	Env var name holding the DSN (falls back to OTEL_UPTRACE_DSN / UPTRACE_DSN)
query_port	int	Dashboard read path: the Uptrace UI/API port (default 14318; 443 behind an HTTPS ingress)
user_token / user_token_env	string	Dashboard read path: an Uptrace user token (Settings → API tokens); falls back to UPTRACE_USER_TOKEN. The DSN's project token only ingests
project_id	int	Dashboard read path: the Uptrace project to query (default 1)

All three signals on by default. See Uptrace.

openobserve

Field	Type	Description
endpoint	string	Required. http://<host>:5080/api/<org>/v1/traces, or the bare origin http://<host>:5080, which the plugin completes with org. Also via OTEL_OPENOBSERVE_ENDPOINT
user / user_env	string	Basic-auth user (falls back to OTEL_OPENOBSERVE_USER / OPENOBSERVE_USER)
password / password_env	string	Basic-auth password (falls back to OTEL_OPENOBSERVE_PASSWORD / OPENOBSERVE_PASSWORD)
stream_name	string	Optional stream name (OTEL_OPENOBSERVE_STREAM)
org	string	Org that completes a bare-origin endpoint (OTEL_OPENOBSERVE_ORG, default default); ignored when endpoint has a path. The dashboard also reads it

All three signals on by default. See OpenObserve.

parseable

Field	Type	Description
endpoint	string	Required. Parseable ingestor OTLP traces endpoint, ending in /v1/traces
api_key	string	Parseable API key (inline; discouraged)
api_key_env	string	Env var holding the key (falls back to OTEL_PARSEABLE_API_KEY, then PARSEABLE_API_KEY). The key is required and is sent as X-API-Key
traces_dataset	string	Traces dataset (default: hermes-traces)
metrics_dataset	string	Metrics dataset (default: hermes-metrics)
logs_dataset	string	Logs dataset (default: hermes-logs)

The plugin supplies signal-specific X-P-Stream and X-P-Log-Source headers automatically. See Parseable.

honeycomb

Field	Type	Description
api_key	string	Honeycomb ingest key (inline; discouraged)
api_key_env	string	Env var name holding the key (falls back to OTEL_HONEYCOMB_API_KEY / HONEYCOMB_API_KEY)
region	string	us (default) or eu; selects the endpoint when none is given
dataset	string	Optional x-honeycomb-dataset header. Only honored by Classic keys — modern Environments keys ignore it
endpoint	string	Override; skips the region default. Also via OTEL_HONEYCOMB_ENDPOINT

The plugin sets x-honeycomb-team from the key automatically and enables all three signals. See Honeycomb for dataset routing details.

weave

Field	Type	Description
api_key	string	W&B API key (inline; discouraged)
api_key_env	string	Env var name holding the key (falls back to OTEL_WEAVE_API_KEY / WANDB_API_KEY)
entity	string	W&B entity/team; copied to Resource attribute wandb.entity
entity_env	string	Env var name holding the entity (falls back to WANDB_ENTITY / DEFAULT_WANDB_ENTITY)
project	string	W&B project; copied to Resource attribute wandb.project
project_env	string	Env var name holding the project (falls back to WANDB_PROJECT / DEFAULT_WANDB_PROJECT)
base_url	string	W&B base URL. Cloud default is https://trace.wandb.ai; Dedicated Cloud / Self-Managed hosts such as https://acme.wandb.io get /traces/otel/v1/traces appended
endpoint	string	Override; skips base_url construction. Also via OTEL_WEAVE_ENDPOINT / WANDB_OTLP_ENDPOINT

The plugin sets the wandb-api-key header automatically. Weave is traces-only by default; set metrics: true / logs: true only if W&B documents ingest for those signals or you are pointing at a compatible collector. wandb.entity and wandb.project may also be supplied via top-level resource_attributes; conflicting values fail startup.

langsmith

Field	Type	Description
api_key / api_key_env	string	Required. LangSmith API key, sent as x-api-key (falls back to OTEL_LANGSMITH_API_KEY / LANGSMITH_API_KEY)
project / project_env	string	Optional project, sent as the Langsmith-Project header (falls back to OTEL_LANGSMITH_PROJECT / LANGSMITH_PROJECT)
region	string	us (default) or eu; picks the host when endpoint is unset
endpoint	string	Override. An API base gets /otel/v1/traces appended. Also via OTEL_LANGSMITH_ENDPOINT / LANGSMITH_ENDPOINT

Traces only. See LangSmith.

elastic

Field	Type	Description
endpoint	string	Required. Elastic Cloud managed OTLP URL (https://<deployment>.ingest.<region>.<csp>.elastic.cloud) or a self-hosted EDOT Collector's OTLP/HTTP base. Also via OTEL_ELASTIC_ENDPOINT. A base URL gets /v1/traces appended; /v1/metrics and /v1/logs are derived from it
api_key	string	Elastic API key (inline; discouraged). Sent as Authorization: ApiKey <key>; the header is omitted entirely when no key resolves (a local collector)
api_key_env	string	Env var name holding the key (falls back to OTEL_ELASTIC_API_KEY / ELASTIC_API_KEY)
dataset	string	Optional; copied to the data_stream.dataset Resource attribute. Lowercase letters, digits, _ and ., no -, at most 100 characters. The collector appends .otel
namespace	string	Optional; copied to the data_stream.namespace Resource attribute, same character rules
metrics_temporality	string	Preset delta for this type (Elasticsearch does not take cumulative histograms); cumulative overrides

An invalid dataset / namespace skips the entry at startup with a warning rather than failing the agent. Both attributes are set on the shared Resource, so every configured backend receives them; two elastic entries with different values conflict at startup. See Elastic.

openlit

Field	Type	Description
endpoint	string	Required. The OpenLIT OTLP/HTTP receiver base: http://localhost:4338 for the bundled stack, http://<host>:4318 upstream (the UI port does not proxy OTLP on the 2.1.0 image). Also via OTEL_OPENLIT_ENDPOINT. A base URL gets /v1/traces appended; /v1/metrics and /v1/logs are derived from it
api_key	string	OpenLIT API key (inline; discouraged). Sent as Authorization: Bearer <key> to scope ingest to an organisation, project and environment; the header is omitted when no key resolves
api_key_env	string	Env var name holding the key (falls back to OTEL_OPENLIT_API_KEY / OPENLIT_API_KEY)
metrics / logs / traces	bool	Per-signal toggles; all three default on

See OpenLIT.

mlflow

Field	Type	Description
endpoint	string	Required. MLflow tracking server (http://localhost:5001 for the bundled stack, http://<host>:5000 upstream). Also via OTEL_MLFLOW_ENDPOINT. A base URL gets /v1/traces appended
experiment_id	string	Experiment that receives the traces, sent as the mandatory x-mlflow-experiment-id header. Default 0 (the built-in Default experiment)
experiment_id_env	string	Env var name holding the experiment id (falls back to OTEL_MLFLOW_EXPERIMENT_ID / MLFLOW_EXPERIMENT_ID)
workspace	string	Optional; sent as X-MLFLOW-WORKSPACE
api_key / api_key_env	string	Optional tracking token, sent as Authorization: Bearer <token> (falls back to OTEL_MLFLOW_API_KEY / MLFLOW_TRACKING_TOKEN)
metrics / logs	bool	Default off: the server has no /v1/metrics or /v1/logs route (404)

See MLflow.

opik

Field	Type	Description
endpoint	string	Opik base URL: http://localhost:5173 for the bundled stack, or a full …/api/v1/private/otel/v1/traces URL. Default https://www.comet.com/opik (Comet cloud). Also via OTEL_OPIK_ENDPOINT or the SDK's OPIK_URL_OVERRIDE
api_key / api_key_env	string	Comet API key, sent as a bare Authorization: <key> header (Opik's scheme; falls back to OTEL_OPIK_API_KEY / OPIK_API_KEY). Not needed on a self-hosted deployment
workspace	string	Comet workspace → Comet-Workspace header (cloud; falls back to OPIK_WORKSPACE)
project / project_env	string	Opik project → projectName header (falls back to OPIK_PROJECT_NAME; Opik uses "Default Project" when absent)
metrics / logs	bool	Default off: only /traces exists under the OTLP prefix

See Comet Opik.

laminar

Field	Type	Description
endpoint	string	Laminar app-server base: http://localhost:8100 for the bundled stack (upstream publishes 8000; the frontend port 5667 does not ingest). Default https://api.lmnr.ai (Laminar cloud). Also via OTEL_LAMINAR_ENDPOINT / LMNR_BASE_URL
api_key / api_key_env	string	Required. Project API key, sent as Authorization: Bearer <key> (falls back to OTEL_LAMINAR_API_KEY / LMNR_PROJECT_API_KEY). The key names the project
metrics	bool	Default off: /v1/metrics answers 200 and stores nothing. true only with a collector in front
logs	bool	Default on (log records are stored)

See Laminar.

langwatch

Field	Type	Description
endpoint	string	LangWatch base: http://localhost:5560 for the bundled stack, or the /api/otel prefix, or a full per-signal URL. Default https://app.langwatch.ai. Also via OTEL_LANGWATCH_ENDPOINT / LANGWATCH_ENDPOINT
api_key / api_key_env	string	Required. Project API key (sk-lw-…), sent as Authorization: Bearer <key> (falls back to OTEL_LANGWATCH_API_KEY / LANGWATCH_API_KEY)
project / project_env	string	Optional project id → X-Project-Id, needed only with a service key (falls back to LANGWATCH_PROJECT_ID)
metrics / logs / traces	bool	All three default on; the plugin derives /api/otel/v1/metrics and /api/otel/v1/logs from the traces URL

See LangWatch.

latitude

Field	Type	Description
endpoint	string	Latitude ingest base: http://localhost:3002 for the bundled stack. Default https://ingest.latitude.so (Latitude cloud). Also via OTEL_LATITUDE_ENDPOINT / LATITUDE_INGEST_URL. A base URL gets /v1/traces appended
api_key / api_key_env	string	Required. API key, sent as Authorization: Bearer <key> (falls back to OTEL_LATITUDE_API_KEY / LATITUDE_API_KEY)
project / project_env	string	Required. Project slug for the mandatory X-Latitude-Project header (falls back to LATITUDE_PROJECT); spans without a project are rejected
metrics / logs	bool	Default off: the ingest service has only /v1/traces

See Latitude.

Env var interpolation in headers:

Inside any headers: value, and any other export field of a backends: entry such as api_key, dsn, password or endpoint, ${VAR_NAME} is replaced with the env var's value when the config is loaded:

headers:
  Authorization: "Bearer ${OTEL_AUTH_TOKEN}"
  x-honeycomb-team: ${HONEYCOMB_API_KEY}

A missing env var logs a startup warning and the literal ${VAR} is sent (which fails auth, but visibly so).

Header names are not expanded. The dashboard expands ${VAR} in each backend entry the same way before it queries the backend, so a credential written as ${VAR} works for both exporting and reading back.

Precedence

For every field, precedence (highest → lowest) is:

1. HERMES_OTEL_* env var (if applicable — see Env var reference)
2. config.yaml value
3. Built-in default

Validation

On startup the plugin validates the config and:

• Logs a warning naming the key and keeps the default for a value that cannot be parsed as the field's type (yaml or HERMES_OTEL_* env var)
• Logs a single warning and uses an empty config if the YAML fails to parse
• Logs a warning and ignores the file if it exists but pyyaml is not installed in the Hermes venv
• Logs a warning and skips a backends: entry it cannot resolve (missing endpoint, unknown type)

The plugin never crashes Hermes because of config — at worst it disables itself with a clear log line.