[rbarbadillo]

Problem

Dedicated-mode telemetry always exported to https://api.mistral.ai/telemetry/v1/traces, whatever the client's server_url was. For other deployments, Mistral(server_url="https://<host>", api_key=<key>) sent API calls to that host but spans to api.mistral.ai, which got a 401 (one exporter log line), so all SDK traces were lost.

Change

The exporter endpoint now resolves as:

1. MISTRAL_OTLP_TRACES_ENDPOINT, if set and non-blank (unchanged override)
2. the client's explicit server_url + /telemetry/v1/traces
3. https://api.mistral.ai/telemetry/v1/traces

The named eu/us servers keep exporting to api.mistral.ai on purpose. The regional hosts don't serve the telemetry route (unauthenticated probes: /v1/models returns 401 on all three hosts, /telemetry/v1/traces returns 401 on api.mistral.ai but 404 on api.eu/api.us). Following them would break telemetry for regional users.

MISTRAL_TELEMETRY_ENDPOINT is kept (now built from SERVERS[SERVER_GLOBAL] + MISTRAL_TELEMETRY_PATH) for backward compatibility. Only hand-owned files changed: src/mistralai/extra/ and the hand-written telemetry section of README.md.

Behaviour changes

• A client whose server_url points at a proxy or gateway now exports traces there instead of api.mistral.ai. Set MISTRAL_OTLP_TRACES_ENDPOINT to keep the old destination.
• An explicit server_url="https://api.eu.mistral.ai" (rather than server="eu") gets a 404 for telemetry. Use server="eu" or the env override.

Tests

New TestTelemetryEndpoint cases use a real client and TracerProvider with a mock transport and exporter, for both explicit configure_telemetry and MISTRAL_SDK_TELEMETRY=dedicated auto-config. They cover:

• default, global, eu and us servers (traces go to api.mistral.ai)
• custom URL, trailing slash, path prefix, localhost:port, and server="eu" with an explicit URL (traces go to server_url)
• blank env overrides and env override precedence

Local results: observability suite 208 passed + 40 subtests; unittest discovery of test_telemetry.py OK; ruff check, mypy and pyright clean.

Verify end-to-end against a deployment with a custom server_url.

Follow-ups

Regional hosts don't serve /telemetry/v1/traces yet. Once they do, the SDK can follow the named regions too.