[eersnington]

ModelRuntime skips pi-ai's observeModelRequest, so default pi() actors have no model spans.

pi.durable.phase  pi.generation request
└── chat claude-opus-5-5

Pi attribute	Exported as
pi.ai.request, pi.ai.poll	chat <model>
provider	gen_ai.provider.name
model	gen_ai.request.model
usage.input + cache read + cache write	gen_ai.usage.input_tokens
usage.output	gen_ai.usage.output_tokens
cost.total	gen_ai.usage.cost_usd

• The adapter translates Pi's model spans, so every actor exports the same span, with or without its own models.
• traceModelRequests wraps the runtime that createActorModelRuntime builds and emits Pi's span names, because pi-ai does not export observeModelRequest.
• It is a Proxy, because completeSimple calls streamSimple inside ModelRuntime. Patched methods would give that call two spans.
• tests/tracing-models.test.ts expects exactly one span per call, so it fails when Pi fixes ModelRuntime. Delete the wrapper then. Users see the same spans.
• A failed attempt records error.type: provider_error and no error text.

---

This is part 2 of 2 in a stack:

•  2  feat(pi): trace model requests #386 👈
•  1  feat(pi): trace Pi Durable with OpenTelemetry #385

[github-actions]

📟 Pip-Boy · dc429ab

📦 Packages · fresh npm install resolve, no lockfile · this PR vs base

No notable install size, dependency, or entrypoint changes across 10 packages.

All 10 packages · linux-x64-gnu

package (linux-x64-gnu)	@latest	base	this PR	Δ vs base	packages
@rivet-dev/pi	372.8 MB	381.9 MB	381.9 MB	+8.5 KB (+0.0%)	220 (0)
@rivet-dev/sandbox-adapter	113.8 KB	114.5 KB	114.5 KB	0	1 (0)
@sandbox-agent/cli-shared	27.2 KB	27.2 KB	27.2 KB	0	1 (0)
@sandbox-agent/persist-indexeddb	12.4 KB	12.4 KB	12.4 KB	0	1 (0)
@sandbox-agent/persist-postgres	12.3 KB	12.3 KB	12.3 KB	0	1 (0)
@sandbox-agent/persist-rivet	12.2 KB	12.2 KB	12.2 KB	0	1 (0)
@sandbox-agent/persist-sqlite	12.3 KB	12.3 KB	12.3 KB	0	1 (0)
@sandbox-agent/react	41.6 MB	41.9 MB	41.9 MB	0	15 (0)
acp-http-client	6.7 MB	6.7 MB	6.7 MB	0	3 (0)
sandbox-agent	31.0 MB	31.0 MB	31.0 MB	0	8 (0)

🧹 Rust dependencies

Skipped: this PR doesn't change any Rust code or dependencies.

🦀 Binaries

Skipped: this PR doesn't change any Rust code.

⏱ Timing

job	wall time	slowest step
changes	23s	checkout · 19s
zizmor	20s	checkout · 12s
footprint	2m46s	Pack the base · 40s
⏭ hygiene	—	skipped
⏭ native · ${{ matrix.platform }}	—	skipped
⏭ self-test	—	skipped
report	30s	setup-node · 12s

🔭 Full CI trace for this commit

One OpenTelemetry trace of CI and Pip-Boy for dc429ab: every job and step, with the sizes above attached. Run after CI finishes.

pnpm install --frozen-lockfile --filter 'pipboy...'
pnpm --filter pipboy pipboy trace --sha dc429abe4c46a59508f1edb50301b593ea0e34ef

Add --otlp <url> to send it to any OTLP/HTTP collector.

Agent instruction: From a rivet-dev/agents checkout, run the commands above, then read the trace file the last command prints. List the slowest jobs and steps and explain where CI time went.