Public API (V2)

The Public API (V2) is a REST API for reading raw application data: metrics, traces, logs, Kubernetes metrics, and deploy statistics. It complements the GraphQL API, which manages models such as apps, incidents, dashboards, and alerts. As a rule of thumb, use the REST API to read data and the GraphQL API to manage configuration.

If you’re building an AI agent or assistant, AppSignal MCP exposes this data to agents directly — you may not need to call this API yourself.

Base URL

All endpoints are served under /api/v2 on the appsignal.com domain:

https://appsignal.com/api/v2

Authentication

Requests are authenticated with your personal API token, passed either as a bearer token or as a query parameter. You can find your token in the personal settings screen.

curl -H "Authorization: Bearer YOUR-PERSONAL-API-TOKEN" \
  https://appsignal.com/api/v2/metrics/names/YOUR-SITE-ID

curl "https://appsignal.com/api/v2/metrics/names/YOUR-SITE-ID?token=YOUR-PERSONAL-API-TOKEN"

Your token grants access to the same sites and organizations you can see in AppSignal. Most requests are scoped to a single site_id; tracing endpoints use a site_ids array so they can search across multiple sites. The API checks that your token has access to every requested site before returning data. To verify a token itself, call GET /api/v2/auth. Your site_id is the ID in your app’s URL: https://appsignal.com/<organization>/sites/<SITE_ID>. For log queries you also need a log source ID — see finding your site and source IDs.

Verify a token

GET /api/v2/auth

Returns a JSON object with a message confirming the authenticated user ID.

Requests and responses

Most endpoints use POST with a JSON body and return JSON. Read-only lookups (such as listing metric names) use GET with path parameters. Set Content-Type: application/json on requests with a body. Times are ISO 8601 strings. Most query bodies take a from and to time range plus either a site_id or, for tracing endpoints, a site_ids array. For a complete, auto-generated reference of every endpoint, request, and response type, see the REST API reference.

Error responses

Any endpoint can return these non-2xx responses:

Status	Meaning	Body
`401`	Missing or invalid token	`{ "error": "Unauthorized" }`
`404`	Route or resource not found	`{ "error": "Not found" }`
`422`	Request parsed but cannot be processed	Error envelope (see the following section)
`500`	Unhandled server-side failure	`{ "error": "<message>" }`

422 envelope

Every 422 response uses the same envelope, so you can handle them in one place:

{
  "error": "<stable_slug>",
  "message": "<human-readable message>",
  "details": {}
}

error: a stable, machine-readable slug. Branch on this in your code.
message: a human-readable message, safe to display.
details: an optional object whose shape depends on error.

One slug you may encounter is legacy_log_query_syntax, returned when a logs query uses the legacy attributes.<name>_<type> syntax. See querying logs for the current query language.

Endpoints

Metrics

Method	Path	Description
`POST`	`/api/v2/metrics/timeseries`	Query metric data as a timeseries
`POST`	`/api/v2/metrics/list`	Query aggregated metric data as a list with grouping
`GET`	`/api/v2/metrics/names/{site_id}`	List all metric names for a site
`GET`	`/api/v2/metrics/type_and_tags/{site_id}/{metric_name}`	Get a metric’s type and available tags

See the metrics reference.

Tracing

Method	Path	Description
`POST`	`/api/v2/tracing/locator`	Locate a trace across sites by trace ID
`POST`	`/api/v2/tracing/trace`	Get all spans for a trace
`POST`	`/api/v2/tracing/trace/performance`	Get spans for a performance trace
`POST`	`/api/v2/tracing/trace/error`	Get spans for an error trace
`POST`	`/api/v2/tracing/traces/performance`	List performance traces
`POST`	`/api/v2/tracing/traces/errors`	List error traces
`POST`	`/api/v2/tracing/actions`	List performance actions with aggregated metrics
`POST`	`/api/v2/tracing/action_edges`	List upstream and downstream edges for an action
`POST`	`/api/v2/tracing/site_edges`	List service dependency edges for a site
`POST`	`/api/v2/tracing/slow_events`	List slow events with aggregated stats
`POST`	`/api/v2/tracing/slow_events/actions`	List actions related to a slow event

See the tracing reference.

Logs

Method	Path	Description
`POST`	`/api/v2/logs/lines`	Search log lines

See the logs reference.

Kubernetes

Method	Path	Description
`POST`	`/api/v2/kubernetes/nodes`	Query node metrics
`POST`	`/api/v2/kubernetes/pods`	Query pod metrics
`POST`	`/api/v2/kubernetes/pods/overview`	Query pod overview with labels and status

See the Kubernetes reference.

Deploys

Method	Path	Description
`POST`	`/api/v2/deploys/stats`	Get deploy statistics for a revision

See the deploys reference.

Check-ins

Method	Path	Description
`POST`	`/api/v2/check_ins/test_cron`	Test and validate a cron schedule expression

See the check-ins reference.

Saved visuals

Method	Path	Description
`GET`	`/api/v2/saved_visuals/{id}`	Retrieve a saved visual as JSON
`GET`	`/api/v2/saved_visuals/{id}/csv`	Download a saved visual as CSV

Saved visual endpoints do not require authentication. See the saved visuals reference.

System

Method	Path	Description
`GET`	`/api/v2/auth`	Verify that a token is valid

AppSignal API

MCP server

AppSignal CLI

Base URL

Authentication

Verify a token

Requests and responses

Error responses

422 envelope

Endpoints

Metrics

Tracing

Logs

Kubernetes

Deploys

Check-ins

Saved visuals

System

​Base URL

​Authentication

​Verify a token

​Requests and responses

​Error responses

​422 envelope

​Endpoints

​Metrics

​Tracing

​Logs

​Kubernetes

​Deploys

​Check-ins

​Saved visuals

​System

Base URL

Authentication

Verify a token

Requests and responses

Error responses

422 envelope

Endpoints

Metrics

Tracing

Logs

Kubernetes

Deploys

Check-ins

Saved visuals

System