# Create dependency graph URL: https://docs.hanzo.ai/docs/openapi/o11y/post-o11y-dependency-graph > Returns the service dependency graph over the requested window: every parent→child edge observed, with call and error rates and latency percentiles per edge. `POST /v1/o11y/dependency_graph` > [O11y →](https://docs.hanzo.ai/docs/openapi/o11y) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides) | | | | ------------- | ----------------------------------------------- | | **Address** | `https://api.hanzo.ai/v1/o11y/dependency_graph` | | **Method** | `POST` | | **Operation** | `post_o11y_dependency_graph` | | **Auth** | `Authorization: Bearer $HANZO_API_KEY` | Returns the service dependency graph over the requested window: every parent→child edge observed, with call and error rates and latency percentiles per edge. Callers need the viewer role; the runtime's own gate enforces it. ## Request 9 fields, body `application/json` (required). | Field | In | Type | Required | Description | | --------------------- | ---- | --------------------- | -------- | --------------------------------------------------------------------------------------------------------------------------- | | `end` | body | string | yes | End is the window end, as epoch nanoseconds. | | `start` | body | string | yes | Start is the window start, as epoch nanoseconds. | | `tags` | body | o11y.O11yTagFilter\[] | — | Tags narrow the graph to spans matching every condition. | | `tags[].boolValues` | body | boolean\[] | — | BoolValues are the values matched when the tag holds booleans. | | `tags[].key` | body | string | — | Key is the tag to test. | | `tags[].numberValues` | body | number (double)\[] | — | NumberValues are the values matched when the tag holds numbers. | | `tags[].operator` | body | string | — | Operator is the comparison to apply — in, not\_in, equals, contains and the other operators the trace filter grammar names. | | `tags[].stringValues` | body | string\[] | — | StringValues are the values matched when the tag holds strings. | | `tags[].tagType` | body | string | — | TagType says which kind of value the tag holds: string, number or bool. | ## Response | Status | Body | Meaning | | --------- | ---------------------- | ----------------- | | `200` | o11y.O11yDependency\[] | ok | | `202` | Approval | held for approval | | `default` | problem-details | refused | `200` body — 10 fields. | Field | In | Type | Always | Description | | -------------- | ---- | ---------------- | ------ | ----------------------------------------------------------- | | `[].callCount` | body | integer (uint64) | — | CallCount is how many calls crossed the edge in the window. | | `[].callRate` | body | number (double) | — | CallRate is calls per second. | | `[].child` | body | string | — | Child is the called service. | | `[].errorRate` | body | number (double) | — | ErrorRate is the percentage of calls that erred. | | `[].p50` | body | number (double) | — | P50 is the median call duration, in nanoseconds. | | `[].p75` | body | number (double) | — | P75 is the 75th-percentile call duration, in nanoseconds. | | `[].p90` | body | number (double) | — | P90 is the 90th-percentile call duration, in nanoseconds. | | `[].p95` | body | number (double) | — | P95 is the 95th-percentile call duration, in nanoseconds. | | `[].p99` | body | number (double) | — | P99 is the 99th-percentile call duration, in nanoseconds. | | `[].parent` | body | string | — | Parent is the calling service. | Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors). ## Examples **CLI** ```bash hanzo o11y dependency_graph \ --end \ --start ``` **SDK** **.ts** ```ts import { Configuration, O11yApi } from 'hanzoai'; const api = new O11yApi(new Configuration({ accessToken: process.env.HANZO_API_KEY })); const { data } = await api.postO11yDependencyGraph({ start: "", end: "" }); ``` **.py** ```python from hanzoai.cloud import ApiClient, Configuration from hanzoai.cloud.api import O11yApi client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"])) result = O11yApi(client).post_o11y_dependency_graph(start="", end="") ``` **.go** ```go cfg := hanzoai.NewConfiguration() cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY")) client := hanzoai.NewAPIClient(cfg) resp, _, err := client.O11yAPI.PostO11yDependencyGraph(context.Background()).Execute() if err != nil { return err } ``` **.rs** ```rust use hanzo_client::apis::{configuration::Configuration, o11y_api}; let mut cfg = Configuration::new(); cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok(); let result = o11y_api::post_o11y_dependency_graph(&cfg, Default::default()).await?; ``` **.java** ```java import ai.hanzo.cloud.ApiClient; import ai.hanzo.cloud.api.O11yApi; ApiClient client = new ApiClient(); client.setBearerToken(System.getenv("HANZO_API_KEY")); var result = new O11yApi(client).postO11yDependencyGraph(); ``` **HTTP** ```bash curl -X POST https://api.hanzo.ai/v1/o11y/dependency_graph \ -H "Authorization: Bearer $HANZO_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "start": "", "end": "" }' ``` **MCP** MCP reaches **o11y** through the `o11y` tool, which names its 307 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them: ```bash curl -X POST https://api.hanzo.ai/v1/mcp \ -H "Content-Type: application/json" \ -d '{ "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "describe", "arguments": { "op": "list_o11y_autocomplete_aggregate_attributes" } } }' ``` --- [O11y API](https://docs.hanzo.ai/docs/openapi/o11y) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)