mobius-operations-trace-py

Request-flow reconstruction and HUMAN_API replay for Mobius Python (FastAPI) services. Python port of platform-artifact-lifecycle-lib + platform-artifact-lifecycle-web (MPH-926 / MPH-928), verified against the Java source (OperationTraceServiceImpl, LifecycleOperationsExceptionHandler).

Relies on action-log rows carrying spanid / parentservicespanid / requestid / httpmethod / httpurl / requesterid / actionsource, written by mobius-tracer-py + mobius-auditlog-py.

What it does

• get_request_flow(txnid, requestid) — queries action logs (either identifier alone is enough) and rebuilds the causal call tree (HUMAN_API entry point first, then each service hop it triggered, in call order) from the spanid / parentservicespanid fields.
• replay_request(txnid, requestid) — finds the originating HUMAN_API call, exchanges the original requester's identity for a bearer token, and re-issues that exact HTTP call (method/URL/body).

Both are exposed as FastAPI endpoints:

• GET /v1/operations/request-flows?txnid=...&requestid=...
• POST /v1/operations/request-replays?txnid=...&requestid=...

Error handling mirrors the Java REST layer:

• Internal failures (missing identifiers, PI lookup failure, missing HUMAN_API fields, replay connectivity failure) → HTTP 400 with the same envelope LifecycleOperationsExceptionHandler emits (timestamp, origin, errorCode, errorMessage, httpStatusCode, actionsRequired).
• A replayed target's own response — even a 4xx/5xx — is forwarded verbatim instead of raised, with the outer HTTP status set to match the target's.

Usage

This package has no hard dependency on a specific action-log store or IAM client — you supply small adapters:

from mobius_operations_trace import setup_operations_trace

setup_operations_trace(
    app,
    token_provider=my_token_provider,  # TokenProvider protocol
    instances_list_url="http://pi-service/v2.0/schemas/{schemaId}/instances/list",
    schema_id="action-log-schema-id",
)

instances_list_url must contain a literal {schemaId} placeholder — PI takes the schema id as a URL path variable, not a body field (matches lifecycle.operations.trace.instances-list-url on the Java side). Pass action_log_source instead of instances_list_url/schema_id to bypass the built-in PI-backed source entirely.

TokenProvider has a single method, retrieve_token_from_tenant_id(tenant_id) — used both to authenticate the PI query (with the fixed PI_SERVICE_TENANT_ID) and to authenticate a replay as the original requester (with the HUMAN_API row's requesterid), matching the Java side's single IamVaultUtils.retrieveTokenFromTenantId method.

See mobius_operations_trace.pi_client.ActionLogSource and mobius_operations_trace.tokens.TokenProvider for the full adapter contracts.