agentruntimecontrolprotocol · nficano · May 24, 2026 · May 24, 2026
diff --git a/docs/architecture.md b/docs/architecture.md
@@ -142,20 +142,19 @@ Clients can pin to a specific agent version:
 
 ```python
 handle = await client.submit(
-    agent="summarise",
+    agent="summarise@2",
     input={"url": "https://example.com"},
-    agent_version="2",
 )
 ```
 
 Runtimes register versioned agents:
 
 ```python
-runtime.register_agent("summarise", summarise_v1, version="1")
-runtime.register_agent("summarise", summarise_v2, version="2")
+runtime.register_agent_version("summarise", "1", summarise_v1)
+runtime.register_agent_version("summarise", "2", summarise_v2)
 ```
 
-If the client omits `agent_version`, the runtime uses the latest registered version.
+If the client omits the version suffix, the runtime uses the latest registered version.
 
 ## Middleware
 

diff --git a/docs/cli.md b/docs/cli.md
@@ -13,49 +13,47 @@ pip install arcp
 
 ### `arcp serve`
 
-Start an ARCP runtime serving agents from a Python module.
+Run the built-in demo runtime.
 
 ```bash
-arcp serve my_module:runtime --host 0.0.0.0 --port 8080
+arcp serve --token demo-token --principal cli-user
 ```
 
 **Arguments:**
 
 | Argument | Default | Description |
 |---|---|---|
-| `MODULE:ATTR` | required | Python import path to an `ARCPRuntime` instance |
 | `--host` | `127.0.0.1` | Bind address |
-| `--port` | `8080` | Bind port |
-| `--reload` | off | Auto-reload on file changes (dev only) |
+| `--port` | `7777` | Bind port |
+| `--token` | required | Demo bearer token to accept |
+| `--principal` | `cli-user` | Principal bound to the accepted token |
+| `--db` | off | Optional SQLite event log path |
 
 ### `arcp submit`
 
 Submit a job to a running runtime and print the result.
 
 ```bash
-arcp submit ws://localhost:8080/arcp summarise '{"url":"https://example.com"}' \
-  --token my-bearer-token
+arcp submit --url ws://localhost:7777/arcp --agent echo \
+  --input '{"url":"https://example.com"}' --token my-bearer-token
 ```
 
 **Arguments:**
 
 | Argument | Description |
 |---|---|
-| `URL` | WebSocket URL of the runtime |
-| `AGENT` | Agent name |
-| `INPUT` | JSON-encoded input (use `@file.json` to read from file) |
+| `--url` | WebSocket URL of the runtime |
+| `--agent` | Agent name |
+| `--input` | JSON-encoded input |
 | `--token` | Bearer token |
-| `--lease-max-cost` | Maximum spend in USD (e.g. `0.10`) |
-| `--lease-expires-in` | Maximum wall time in seconds |
-| `--idempotency-key` | Idempotency key |
-| `--stream` | Print result chunks as they arrive |
+| `--lease` | Lease JSON object |
 
 ### `arcp tail`
 
 Tail the event stream for a job in real time.
 
 ```bash
-arcp tail ws://localhost:8080/arcp JOB_ID --token my-bearer-token
+arcp tail --url ws://localhost:7777/arcp --job-id JOB_ID --token my-bearer-token
 ```
 
 Prints each `JobEvent` as a JSON line. Press `Ctrl-C` to stop.
@@ -65,30 +63,7 @@ Prints each `JobEvent` as a JSON line. Press `Ctrl-C` to stop.
 Replay a recorded event stream from a JSONL file.
 
 ```bash
-arcp replay events.jsonl
+arcp replay --db events.sqlite --session SESSION_ID
 ```
 
-Useful for debugging: record a live stream with `arcp tail --output events.jsonl`, then replay it offline.
-
-## Environment variables
-
-All CLI options can also be set via environment variables:
-
-| Variable | CLI equivalent |
-|---|---|
-| `ARCP_TOKEN` | `--token` |
-| `ARCP_HOST` | `arcp serve --host` |
-| `ARCP_PORT` | `arcp serve --port` |
-
-## Shell completion
-
-```bash
-# bash
-arcp --install-completion bash
-
-# zsh
-arcp --install-completion zsh
-
-# fish
-arcp --install-completion fish
-```
+Useful for debugging: record a live stream from `tail` and replay it from the SQLite event log.
diff --git a/docs/conformance.md b/docs/conformance.md
@@ -6,42 +6,43 @@ This page records which sections of the [ARCP v1.1 specification](https://arcp.d
 
 | Spec section | Title | Status | Source |
 |---|---|---|---|
-| §4 | Versioning | ✅ Full | `arcp/_version.py` |
-| §5 | Transport framing | ✅ Full | `arcp/_transport/` |
-| §6 | Sessions | ✅ Full | `arcp/runtime/session.py` |
-| §6.1 | Authentication — Bearer | ✅ Full | `arcp/runtime/auth.py` |
-| §6.1 | Authentication — custom verifier | ✅ Full | `arcp/runtime/auth.py` |
-| §6.2 | Agent versions | ✅ Full | `arcp/runtime/registry.py` |
-| §6.3 | Stream resume | ✅ Full | `arcp/runtime/resume.py` |
-| §7 | Jobs | ✅ Full | `arcp/runtime/job_runner.py` |
-| §7.1 | Idempotency keys | ✅ Full | `arcp/runtime/idempotency.py` |
-| §7.2 | Job cancellation | ✅ Full | `arcp/runtime/job_runner.py` |
-| §8 | Job events | ✅ Full | `arcp/_envelope.py` |
-| §8.1 | `job.queued` | ✅ Full | `arcp/_envelope.py` |
-| §8.2 | `job.started` | ✅ Full | `arcp/_envelope.py` |
-| §8.3 | `job.log` | ✅ Full | `arcp/runtime/context.py` |
-| §8.4 | `job.progress` | ✅ Full | `arcp/runtime/context.py` |
-| §8.5 | `job.result_chunk` | ✅ Full | `arcp/runtime/context.py` |
-| §8.6 | `job.completed` | ✅ Full | `arcp/runtime/job_runner.py` |
-| §8.7 | `job.failed` | ✅ Full | `arcp/runtime/job_runner.py` |
-| §8.8 | `job.cancelled` | ✅ Full | `arcp/runtime/job_runner.py` |
-| §8.9 | `job.heartbeat` | ✅ Full | `arcp/runtime/heartbeat.py` |
-| §9 | Leases | ✅ Full | `arcp/runtime/lease.py` |
-| §9.1 | Cost budgets | ✅ Full | `arcp/runtime/lease.py` |
-| §9.2 | Time budgets (`expires_in_s`) | ✅ Full | `arcp/runtime/lease.py` |
-| §9.3 | `expires_at` (absolute timestamp) | ✅ Full | `arcp/runtime/lease.py` |
-| §10 | Delegation | ✅ Full | `arcp/runtime/delegation.py` |
-| §11 | Observability | ✅ Full | `arcp/middleware/otel.py` |
-| §12 | Errors | ✅ Full | `arcp/_errors.py` |
-| §13 | Capability negotiation | ✅ Full | `arcp/runtime/capabilities.py` |
-| §14 | List jobs | ✅ Full | `arcp/runtime/job_store.py` |
-| §15 | Vendor extensions | ✅ Full | `arcp/_extensions.py` |
+| §4 | Versioning | ✅ Full | `src/arcp/_version.py` |
+| §5 | Transport framing | ✅ Full | `src/arcp/_transport/` |
+| §6 | Sessions | ✅ Full | `src/arcp/_runtime/session.py` |
+| §6.1 | Authentication — Bearer | ✅ Full | `src/arcp/_auth/bearer.py` |
+| §6.1 | Authentication — custom verifier | ✅ Full | `src/arcp/_auth/jwt.py` |
+| §6.2 | Agent versions | ✅ Full | `src/arcp/_runtime/server.py` |
+| §6.3 | Stream resume | ✅ Full | `src/arcp/_runtime/session.py` |
+| §7 | Jobs | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §7.1 | Idempotency keys | ✅ Full | `src/arcp/_store/idempotency.py` |
+| §7.2 | Job cancellation | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8 | Job events | ✅ Full | `src/arcp/_envelope.py` |
+| §8.1 | `job.queued` | ✅ Full | `src/arcp/_envelope.py` |
+| §8.2 | `job.started` | ✅ Full | `src/arcp/_envelope.py` |
+| §8.3 | `job.log` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.4 | `job.progress` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.5 | `job.result_chunk` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.6 | `job.completed` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.7 | `job.failed` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.8 | `job.cancelled` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §8.9 | `job.heartbeat` | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §9 | Leases | ✅ Full | `src/arcp/_runtime/lease.py` |
+| §9.1 | Cost budgets | ✅ Full | `src/arcp/_runtime/lease.py` |
+| §9.2 | Time budgets (`expires_in_s`) | ✅ Full | `src/arcp/_runtime/lease.py` |
+| §9.3 | `expires_at` (absolute timestamp) | ✅ Full | `src/arcp/_runtime/lease.py` |
+| §10 | Delegation | ✅ Full | `src/arcp/_runtime/_handlers.py` |
+| §11 | Observability | ✅ Full | `src/arcp/middleware/otel.py` |
+| §12 | Errors | ✅ Full | `src/arcp/_errors.py` |
+| §13 | Capability negotiation | ✅ Full | `src/arcp/_runtime/server.py` |
+| §14 | List jobs | ✅ Full | `src/arcp/_runtime/_handler_list_jobs.py` |
+| §15 | Vendor extensions | ✅ Full | `src/arcp/_extensions.py` |
 
 ## Notes
 
 ### §6.3 Stream resume
 
-Resume tokens are opaque strings returned in the `job.started` event. Pass the token in a new `submit()` call with `resume_token=...` to replay missed events from that point forward.
+Resume remains session-scoped in the current implementation. Treat the older
+`resume_token` submit flow as deferred until the runtime exposes it publicly.
 
 ### §9.3 `expires_at`
 

diff --git a/docs/guides/jobs.md b/docs/guides/jobs.md
@@ -23,9 +23,10 @@ print(result.result)
 | `input` | `dict` | Arbitrary JSON-serialisable payload |
 | `lease_request` | `dict` | Budget constraints (see [Leases](leases.md)) |
 | `idempotency_key` | `str` | Deduplicate re-submissions (see below) |
-| `agent_version` | `str` | Pin to a specific agent version |
-| `resume_token` | `str` | Resume an interrupted stream |
-| `resume_from_seq` | `int` | Replay from this event sequence number |
+| `lease_constraints` | `dict` | Optional absolute expiry and related constraints |
+| `max_runtime_sec` | `int` | Maximum runtime before timeout |
+| `trace_id` | `str` | Optional trace correlation id |
+| `parent_job_id` | `str` | Parent job for delegation or tracing |
 
 ## Registering an agent
 
@@ -47,23 +48,23 @@ The `ctx` object gives agents access to logging, progress, streaming, cost repor
 ```python
 async def my_agent(input, ctx):
     await ctx.log("info", "starting")
-    await ctx.progress(0, 100)
+    await ctx.progress(0, total=100)
 
     for i in range(10):
         chunk = await do_work(i)
         await ctx.result_chunk(chunk)
-        await ctx.progress((i + 1) * 10, 100)
-        await ctx.report_cost(0.001)  # USD
+        await ctx.progress((i + 1) * 10, total=100)
+        await ctx.metric({"name": "cost.inference", "value": 0.001, "unit": "USD"})
 
     return {"done": True}
 ```
 
 | Method | Description |
 |---|---|
 | `ctx.log(level, message)` | Emit a `job.log` event |
-| `ctx.progress(done, total)` | Emit a `job.progress` event |
+| `ctx.progress(current, total=..., units=..., message=...)` | Emit a `job.progress` event |
 | `ctx.result_chunk(chunk)` | Emit a `job.result_chunk` event |
-| `ctx.report_cost(usd)` | Accumulate cost against the lease |
+| `ctx.metric(body)` | Emit a `metric` event |
 | `ctx.principal` | The authenticated client identity |
 | `ctx.job_id` | The current job ID |
 | `ctx.session_id` | The current session ID |
@@ -85,7 +86,7 @@ async for event in handle.events():
 ```python
 handle = await client.submit(agent="slow", input={})
 await asyncio.sleep(1.0)
-await handle.cancel()
+await client.cancel_job(handle.job_id)
 # handle.done raises JobCancelledError
 ```
 

diff --git a/docs/guides/leases.md b/docs/guides/leases.md
@@ -14,13 +14,13 @@ handle = await client.submit(
 )
 ```
 
-The agent reports costs via `ctx.report_cost(usd)`:
+The agent reports costs via `ctx.metric(...)`:
 
 ```python
 async def gpt_4_summary(input, ctx):
     response = await call_openai(input["text"])
     cost = response.usage.total_tokens * 0.00003
-    await ctx.report_cost(cost)
+    await ctx.metric({"name": "cost.openai", "value": cost, "unit": "USD"})
     return {"summary": response.text}
 ```
 

diff --git a/docs/guides/observability.md b/docs/guides/observability.md
@@ -45,7 +45,7 @@ trace.set_tracer_provider(provider)
 | `arcp.jobs.active` | Gauge | Currently running jobs |
 | `arcp.jobs.total` | Counter | Total jobs submitted |
 | `arcp.job.duration_ms` | Histogram | Job wall-clock duration |
-| `arcp.job.cost_usd` | Histogram | Job cost (from `ctx.report_cost`) |
+| `arcp.job.cost_usd` | Histogram | Job cost (from `ctx.metric({"name": "cost.*", ...})`) |
 | `arcp.events.total` | Counter | Total events emitted |
 
 ## Propagating trace context

diff --git a/docs/guides/resume.md b/docs/guides/resume.md
@@ -8,7 +8,7 @@ If a connection drops while a job is running, the client can **resume** the even
 
 1. The runtime emits a `job.started` event containing a `resume_token`.
 2. The client stores the token and the last acknowledged `event_seq`.
-3. If the connection drops, the client reconnects and calls `submit()` again with `resume_token=...`.
+3. If the connection drops, the client reconnects and calls `client.resume(..., resume=SessionResume(...))`.
 4. The runtime replays events from `event_seq + 1` onward.
 
 The job itself is **not** re-executed. Only the event stream is replayed.

diff --git a/docs/recipes/ack-backpressure.md b/docs/recipes/ack-backpressure.md
@@ -8,7 +8,7 @@ pauses production and emits a `status` event with
 Source: [`../../examples/ack_backpressure/`](../../examples/ack_backpressure/).
 
 ```sh
-uv run python -m examples.ack_backpressure.runtime &
+uv run python -m examples.ack_backpressure.server &
 uv run python -m examples.ack_backpressure.client
 ```
 

diff --git a/docs/recipes/agent-versions.md b/docs/recipes/agent-versions.md
@@ -8,11 +8,11 @@ the example asserts both jobs ran the expected handler.
 Source: [`../../examples/agent_versions/`](../../examples/agent_versions/).
 
 ```sh
-uv run python -m examples.agent_versions.runtime &
+uv run python -m examples.agent_versions.server &
 uv run python -m examples.agent_versions.client
 ```
 
 ## See also
 
 - Guide: [Sessions](../guides/sessions.md) — agent versions (§6.2).
-- Guide: [Jobs](../guides/jobs.md) — `agent_version` submit option.
+- Guide: [Jobs](../guides/jobs.md) — versioned agent names.
diff --git a/docs/recipes/cancel.md b/docs/recipes/cancel.md
@@ -8,7 +8,7 @@ terminal envelope ships.
 Source: [`../../examples/cancel/`](../../examples/cancel/).
 
 ```sh
-uv run python -m examples.cancel.runtime &
+uv run python -m examples.cancel.server &
 uv run python -m examples.cancel.client
 ```
 

diff --git a/docs/recipes/cost-budget.md b/docs/recipes/cost-budget.md
@@ -2,12 +2,12 @@
 
 A client submits a job with `max_cost_usd: 0.05`; the agent
 reports successive cost increments until the budget reaches zero,
-and the next `ctx.report_cost(...)` call fails with `LeaseExceededError`.
+and the next `ctx.metric(...)` call fails with `LeaseExceededError`.
 
 Source: [`../../examples/cost_budget/`](../../examples/cost_budget/).
 
 ```sh
-uv run python -m examples.cost_budget.runtime &
+uv run python -m examples.cost_budget.server &
 uv run python -m examples.cost_budget.client
 ```
 

diff --git a/docs/recipes/custom-auth.md b/docs/recipes/custom-auth.md
@@ -8,7 +8,7 @@ authentication and the rest of the protocol.
 Source: [`../../examples/custom_auth/`](../../examples/custom_auth/).
 
 ```sh
-uv run python -m examples.custom_auth.runtime &
+uv run python -m examples.custom_auth.server &
 uv run python -m examples.custom_auth.client
 ```
 

diff --git a/docs/recipes/delegate.md b/docs/recipes/delegate.md
@@ -8,7 +8,7 @@ delegation composes the recursive case of jobs / events / leases.
 Source: [`../../examples/delegate/`](../../examples/delegate/).
 
 ```sh
-uv run python -m examples.delegate.runtime &
+uv run python -m examples.delegate.server &
 uv run python -m examples.delegate.client
 ```
 

diff --git a/docs/recipes/heartbeat.md b/docs/recipes/heartbeat.md
@@ -7,7 +7,7 @@ client to surface `HEARTBEAT_LOST` and a `session.error` close.
 Source: [`../../examples/heartbeat/`](../../examples/heartbeat/).
 
 ```sh
-uv run python -m examples.heartbeat.runtime &
+uv run python -m examples.heartbeat.server &
 uv run python -m examples.heartbeat.client
 ```
 

diff --git a/docs/recipes/host-tracing.md b/docs/recipes/host-tracing.md
@@ -9,7 +9,7 @@ without an external collector.
 Source: [`../../examples/host_tracing/`](../../examples/host_tracing/).
 
 ```sh
-uv run python -m examples.host_tracing.runtime &
+uv run python -m examples.host_tracing.server &
 uv run python -m examples.host_tracing.client
 ```
 

diff --git a/docs/recipes/idempotent-retry.md b/docs/recipes/idempotent-retry.md
@@ -8,7 +8,7 @@ idempotency store.
 Source: [`../../examples/idempotent_retry/`](../../examples/idempotent_retry/).
 
 ```sh
-uv run python -m examples.idempotent_retry.runtime &
+uv run python -m examples.idempotent_retry.server &
 uv run python -m examples.idempotent_retry.client
 ```
 

diff --git a/docs/recipes/lease-expires-at.md b/docs/recipes/lease-expires-at.md
@@ -7,7 +7,7 @@ sleeps past the deadline and the next `ctx.authorize(...)` raises
 Source: [`../../examples/lease_expires_at/`](../../examples/lease_expires_at/).
 
 ```sh
-uv run python -m examples.lease_expires_at.runtime &
+uv run python -m examples.lease_expires_at.server &
 uv run python -m examples.lease_expires_at.client
 ```
 

diff --git a/docs/recipes/lease-violation.md b/docs/recipes/lease-violation.md
@@ -8,7 +8,7 @@ the lease validator path and the failure surface in `arcp._errors`.
 Source: [`../../examples/lease_violation/`](../../examples/lease_violation/).
 
 ```sh
-uv run python -m examples.lease_violation.runtime &
+uv run python -m examples.lease_violation.server &
 uv run python -m examples.lease_violation.client
 ```