Conformance — ARCP v1.1 (additive over v1.0) This SDK targets ARCP v1.1 , the
backward-compatible additive revision of v1.0. v1.0 conformance is
preserved in full — all v1.0 sections below report the same status; the
new v1.1 subsections appear after them.
Implemented — feature is present and matches the spec.Deferred — feature is intentionally not yet implemented, with rationale.
Requirement
Status
Location
§4.1 WebSocket MUST be supported (wss://, /arcp path)
Implemented
packages/core/src/transport/websocket.ts (WebSocketTransport); packages/middleware/node/src/index.ts (path defaults to /arcp)
§4.1 JSON text frames only
Implemented
packages/core/src/transport/websocket.ts discards binary frames
§4.2 stdio newline-delimited JSON
Implemented
packages/core/src/transport/stdio.ts
§4.3 Alternate transports MAY exist
Implemented
MemoryTransport (packages/core/src/transport/memory.ts) is the in-process test transport
Requirement
Status
Location
§5.1 arcp field, REQUIRED, MUST be "1.1"
Implemented
packages/core/src/version.ts:PROTOCOL_VERSION = "1.1"; packages/core/src/envelope.ts rejects other values
§5.1 id REQUIRED, ULID/UUIDv7
Implemented
packages/core/src/util/ulid.ts; emitted by buildEnvelope
§5.1 type REQUIRED
Implemented
packages/core/src/envelope.ts
§5.1 session_id REQUIRED on post-welcome envelopes
Implemented
Per-message schemas in packages/core/src/messages/{session,execution}.ts
§5.1 trace_id OPTIONAL, W3C 32-hex
Implemented
packages/core/src/envelope.ts:isValidTraceId
§5.1 job_id REQUIRED when applicable
Implemented
packages/core/src/messages/execution.ts
§5.1 event_seq REQUIRED on job.event/job.result/job.error (monotonic, session-scoped)
Implemented
Schemas + Job.emitEventKind / emitResult / emitErrorEnvelope via SessionContext.nextEventSeq()
§5.1 payload REQUIRED
Implemented
packages/core/src/envelope.ts
§5.1 Unknown top-level fields MUST be ignored
Implemented
RoundTripEnvelopeSchema uses .passthrough()
§5.2 JSON / UTF-8 / int64 only
Implemented
JSON-only transports
Requirement
Status
Location
§6.1 Bearer-token authentication on session.hello
Implemented
packages/core/src/auth/bearer.ts; packages/runtime/src/server.ts:authenticate()
§6.1 Reject missing/invalid token with session.error + close
Implemented
packages/runtime/src/server.ts:emitSessionError + terminate
§6.2 hello payload client/auth/capabilities; welcome payload runtime/resume_token/resume_window_sec/capabilities
Implemented
packages/core/src/messages/session.ts
§6.2 capabilities includes encodings and (runtime) agents
Implemented
packages/core/src/messages/session.ts:CapabilitiesSchema
§6.2 Runtime MUST issue resume_token (≥128 bits entropy); client MUST treat as credential
Implemented
packages/runtime/src/server.ts:newResumeToken() uses 32 random bytes (256 bits)
§6.2 resume_token rotated on every welcome
Implemented
packages/runtime/src/server.ts:handleResume writes a fresh token to resumeStore and emits in the new welcome
§6.3 Resume via session.hello.payload.resume = { session_id, resume_token, last_event_seq }
Implemented
packages/core/src/messages/session.ts:SessionHelloPayloadSchema
§6.3 On resume, replay event_seq > last_event_seq, issue new welcome with same session_id, resume streaming
Implemented
packages/runtime/src/server.ts:handleResume reads via EventLog.readSinceSeq and re-sends frames
§6.3 RESUME_WINDOW_EXPIRED on stale resume
Implemented
packages/core/src/errors.ts:ResumeWindowExpiredError; emitted in server.ts:handleResume
§6.7 Clean close via session.bye { reason }
Implemented
packages/core/src/messages/session.ts:SessionByePayloadSchema
§6.7 Either side MAY initiate; no further messages post-bye
Implemented
packages/runtime/src/server.ts:terminate is idempotent
Requirement
Status
Location
§7.1 job.submit with agent/input/lease_request?/idempotency_key?/max_runtime_sec?
Implemented
packages/core/src/messages/execution.ts:JobSubmitPayloadSchema
§7.1 Runtime → job.accepted { job_id, lease, accepted_at, parent_job_id?, delegate_id?, trace_id? }
Implemented
packages/core/src/messages/execution.ts:JobAcceptedPayloadSchema; packages/runtime/src/job.ts:emitAccepted
§7.1 Runtime MAY reduce, MUST NOT expand the lease
Implemented
packages/runtime/src/lease.ts:validateLeaseShape; no expansion path exists
§7.2 Transport-level idempotency via envelope id (dedupe)
Implemented
packages/core/src/store/eventlog.ts:append is INSERT OR IGNORE
§7.2 Logical idempotency via payload.idempotency_key; same key+principal within ~24h → same job_id
Implemented
packages/runtime/src/server.ts:idempotencyStore and handleJobSubmit
§7.2 Different agent/input under same key → DUPLICATE_KEY
Implemented
packages/runtime/src/server.ts:handleJobSubmit; packages/core/src/errors.ts:DuplicateKeyError
§7.3 States: pending, running, success, error, cancelled, timed_out
Implemented
packages/core/src/messages/execution.ts:JOB_STATES; packages/runtime/src/job.ts:JOB_TRANSITIONS
§7.3 Terminal events job.result (success) / job.error (failure variants), with final_status
Implemented
packages/core/src/messages/execution.ts:JobResultPayloadSchema, JobErrorPayloadSchema
§7.4 Cancellation via job.cancel { reason }; runtime emits job.error{final_status:"cancelled"} within 30s grace
Implemented
packages/runtime/src/server.ts:handleJobCancel + cancelGraceMs (default 30_000)
Requirement
Status
Location
§8.1 Single job.event envelope with payload.kind/payload.ts/payload.body
Implemented
packages/core/src/messages/execution.ts:JobEventPayloadSchema
§8.2 Eight reserved v1.0 kinds: log, thought, tool_call, tool_result, status, metric, artifact_ref, delegate
Implemented
packages/core/src/messages/execution.ts:RESERVED_EVENT_KINDS
§8.2 tool_call.body.call_id links call/result
Implemented
ToolCallBodySchema/ToolResultBodySchema both require call_id
§8.2 Vendor namespace x-vendor.kind allowed; unknown kinds ignored
Implemented
packages/core/src/messages/execution.ts:isVendorEventKind; JobEventPayloadSchema accepts any string kind
§8.3 Sequence numbers SESSION-scoped (single space across concurrent jobs)
Implemented
packages/runtime/src/server.ts:SessionContext.nextEventSeq
§8.3 Strictly monotonic, gap-free across reconnects
Implemented
SessionContext.setEventSeq is updated to the highest replayed value after resume
§8.3 Per-job ordering preserved within session seq
Implemented
Inherits from the session counter
Requirement
Status
Location
§9.1 Lease is IMMUTABLE, granted at submit; capability → glob pattern[]
Implemented
packages/core/src/messages/execution.ts:LeaseSchema; packages/runtime/src/lease.ts:validateLeaseShape
§9.2 Reserved namespaces fs.read, fs.write, net.fetch, tool.call, agent.delegate, cost.budget
Implemented
packages/core/src/messages/execution.ts:RESERVED_CAPABILITY_NAMES
§9.2 Glob * (single segment) / ** (zero+ segments); anchored
Implemented
packages/runtime/src/lease.ts:compileGlob/matchGlob
§9.3 Runtime MUST validate every operation against the lease; PERMISSION_DENIED on fail
Implemented
packages/runtime/src/lease.ts:validateLeaseOp
§9.4 Lease subsetting for delegation
Implemented
packages/runtime/src/lease.ts:isLeaseSubset/assertLeaseSubset
§14 Canonicalize paths/URLs before glob check
Implemented
packages/runtime/src/lease.ts:canonicalizeTarget
Requirement
Status
Location
§10.1 Delegation as job.event with kind: "delegate" carrying {delegate_id, agent, input, lease_request, lease_constraints?}
Implemented
packages/core/src/messages/execution.ts:DelegateBodySchema; emitted by JobContext.delegate()
§10.1 Runtime responds with job.accepted { job_id, parent_job_id, delegate_id, lease }
Implemented
packages/runtime/src/server.ts:createDelegateJob
§10.2 Subset validation surfaces failure as tool_result event on PARENT with LEASE_SUBSET_VIOLATION
Implemented
packages/runtime/src/server.ts:makeDelegateInterceptor
§10.3 Delegated jobs inherit parent trace_id; new span MAY be created
Implemented
packages/runtime/src/server.ts:createDelegateJob
Requirement
Status
Location
§11 trace_id is W3C 32-hex; client SHOULD include on submit; runtime MUST mint if absent, echo on job.accepted.payload.trace_id
Implemented
packages/runtime/src/server.ts:handleJobSubmit
§11 Runtime SHOULD emit OTel spans with arcp.session_id, arcp.job_id, arcp.agent, arcp.lease.capabilities
Implemented
packages/middleware/otel/src/index.ts
§12. Error Taxonomy (v1.0 codes)
Code
Status
Location
PERMISSION_DENIEDImplemented
packages/core/src/errors.ts:PermissionDeniedError
LEASE_SUBSET_VIOLATIONImplemented
packages/core/src/errors.ts:LeaseSubsetViolationError
JOB_NOT_FOUNDImplemented
packages/core/src/errors.ts:JobNotFoundError
DUPLICATE_KEYImplemented
packages/core/src/errors.ts:DuplicateKeyError
AGENT_NOT_AVAILABLEImplemented
packages/core/src/errors.ts:AgentNotAvailableError
CANCELLEDImplemented
packages/core/src/errors.ts:CancelledError
TIMEOUTImplemented
packages/core/src/errors.ts:TimeoutError
RESUME_WINDOW_EXPIREDImplemented
packages/core/src/errors.ts:ResumeWindowExpiredError
HEARTBEAT_LOSTImplemented
packages/core/src/errors.ts:HeartbeatLostError
INVALID_REQUESTImplemented
packages/core/src/errors.ts:InvalidRequestError
UNAUTHENTICATEDImplemented
packages/core/src/errors.ts:UnauthenticatedError
INTERNAL_ERRORImplemented
packages/core/src/errors.ts:InternalError
Error payload { code, message, retryable, details? }
Implemented
packages/core/src/errors.ts:ErrorPayloadSchema
Twenty-three runnable two-process examples under examples/. Each
exercises one v1.0 or v1.1 feature or one host-integration middleware
end-to-end (no mocks; real transport).
v1.0 core:
Directory
Spec
submit-and-stream/§13.1 / §8.2
delegate/§13.2 / §10
resume/§13.3 / §6.3
idempotent-retry/§13.5 / §7.2
lease-violation/§13.4 / §9.3
cancel/§7.4
stdio/§4.2
vendor-extensions/§8.2 / §9.2 / §15
custom-auth/§6.1
v1.1 features (one example per addition):
Directory
Spec
heartbeat/§6.4
ack-backpressure/§6.5 / §8.2
list-jobs/§6.6
subscribe/§7.6 / §6.6
agent-versions/§7.5 / §12
lease-expires-at/§9.5 / §12
cost-budget/§9.6 / §12
progress/§8.2.1
result-chunk/§8.4
Host integrations (one example per middleware):
Directory
Middleware
tracing/@arcp/middleware-otel
express/@arcp/express
fastify/@arcp/fastify
bun/@arcp/bun
§14. Security Considerations
Requirement
Status
Location
§14 wss:// required, bearer not over cleartext
Implemented (deployer-controlled)
SDK does not downgrade
§14 resume_token ≥128 bits entropy
Implemented
packages/runtime/src/server.ts:newResumeToken (256 bits)
§14 Lease MUST be checked even with sandboxing
Implemented (responsibility)
validateLeaseOp is the SDK's interception primitive
§14 Canonicalize paths/URLs before glob check
Implemented
packages/runtime/src/lease.ts:canonicalizeTarget
§14 Buffered events at rest: purge at window expiry
Implemented
packages/runtime/src/server.ts:sweepResume runs on a 60 s interval
§14 Per-session DoS caps (max buffered events / bytes / concurrent jobs); exceed ⇒ INTERNAL_ERROR non-retryable
Implemented
packages/runtime/src/server.ts:SessionContext.checkCaps
§15. IANA / Extension namespace
Requirement
Status
Location
x-vendor.* namespace for vendor extension envelope types and event kindsImplemented
packages/core/src/extensions.ts:isVendorExtensionName; packages/core/src/messages/execution.ts:isVendorEventKind
Unknown x-vendor.* types ignored (drop)
Implemented
packages/core/src/extensions.ts:classifyUnknownType
ARCP v1.1 is fully backward-compatible with v1.0. The arcp envelope
field remains "1". New messages, fields, event kinds, lease
constraints, and error codes are negotiated via the v1.1 features
capability list in session.hello/session.welcome.
Feature negotiation matrix
Feature flag
Spec ref
Status
Where the flag is consumed
heartbeat§6.4
Implemented
packages/runtime/src/server.ts:SessionContext.startHeartbeat; client responds to ping in packages/client/src/client.ts:dispatchRaw
ack§6.5
Implemented
packages/runtime/src/server.ts:registerPostHandshakeHandlers (session.ack handler) + SessionContext.recordAck; client ARCPClient.ack / autoAck
list_jobs§6.6
Implemented
packages/runtime/src/server.ts:handleListJobs; ARCPClient.listJobs
subscribe§7.6
Implemented
packages/runtime/src/server.ts:handleJobSubscribe; ARCPClient.subscribe
lease_expires_at§9.5
Implemented
packages/runtime/src/lease.ts:validateLeaseConstraints; expiry watchdog in server.ts:runHandler
cost.budget§9.6
Implemented
packages/runtime/src/lease.ts:initialBudgetFromLease; Job.applyCostMetric; validateLeaseOp budget check
progress§8.2
Implemented
packages/core/src/messages/execution.ts:ProgressBodySchema; JobContext.progress
result_chunk§8.4
Implemented
packages/core/src/messages/execution.ts:ResultChunkBodySchema; JobContext.streamResult + JobHandle.collectChunks
agent_versions§7.5
Implemented
packages/core/src/messages/execution.ts:parseAgentRef; ARCPServer.registerAgentVersion/setDefaultAgentVersion/resolveAgent
The negotiated set is intersect(session.hello.capabilities.features, session.welcome.capabilities.features). Either peer can introspect
via client.negotiatedFeatures / client.hasFeature(name) and
SessionContext.negotiatedFeatures / SessionContext.hasFeature(name).
Feature handlers MUST refuse to operate if the feature is not in the
intersection (e.g., client.ack(seq) throws INVALID_REQUEST).
Helpers:
packages/core/src/version.ts:V1_1_FEATURES — canonical feature list.packages/core/src/version.ts:intersectFeatures(a, b) — intersection helper.
§6.2 Capabilities (v1.1 additions)
Requirement
Status
Location
§6.2 capabilities.features: string[] on hello and welcome
Implemented
packages/core/src/messages/session.ts:CapabilitiesSchema
§6.2 Effective feature set is the intersection of both lists
Implemented
packages/core/src/version.ts:intersectFeatures; packages/runtime/src/server.ts:makeNegotiatedCapabilities; packages/client/src/client.ts:connectInternal
§6.2 Runtime advertises the rich agents: Array<{name, versions, default?}> shape when agent_versions is negotiated
Implemented
packages/runtime/src/server.ts:ARCPServer.getAgentInventory + makeNegotiatedCapabilities
§6.2 Client SHOULD accept either flat string[] or rich object shape for agents
Implemented
packages/core/src/messages/session.ts:CapabilitiesSchema (union); helper normalizeAgentInventory
Requirement
Status
Location
Feature flag heartbeat
Implemented
packages/core/src/version.ts:V1_1_FEATURES
session.ping / session.pong envelopes ({nonce, sent_at} / {ping_nonce, received_at})Implemented
packages/core/src/messages/session.ts:SessionPingPayloadSchema/SessionPongPayloadSchema
session.welcome.payload.heartbeat_interval_sec advertisedImplemented
packages/core/src/messages/session.ts:SessionWelcomePayloadSchema; packages/runtime/src/server.ts:handleSessionHello
Runtime periodically pings if outbound idle and replies to inbound pings; closes with HEARTBEAT_LOST after 2 silent intervals
Implemented
packages/runtime/src/server.ts:SessionContext.startHeartbeat/heartbeatTick
Client periodically pings if idle and replies to runtime pings
Implemented
packages/client/src/client.ts:dispatchRaw (pong path); ping side TBD when long-lived idle is required
session.ping/session.pong NOT counted in event_seqImplemented
packages/runtime/src/server.ts:SessionContext.dispatchRaw (SKIP_LOG set)
§6.5 Event Acknowledgement
Requirement
Status
Location
Feature flag ack
Implemented
packages/core/src/version.ts:V1_1_FEATURES
session.ack { last_processed_seq } envelopeImplemented
packages/core/src/messages/session.ts:SessionAckPayloadSchema
Runtime records the client's last_processed_seq
Implemented
packages/runtime/src/server.ts:SessionContext.recordAck
Runtime MAY emit a back_pressure status event when lag exceeds a threshold
Implemented
packages/runtime/src/server.ts:SessionContext.emitBackPressureStatus (default threshold 1000, configurable via ARCPServerOptions.backPressureThreshold)
Client ack(seq) helper
Implemented
packages/client/src/client.ts:ARCPClient.ack
Client autoAck coalesces acks (every N events or M ms)
Implemented
packages/client/src/client.ts:scheduleAutoAck (defaults 32 events / 250 ms)
session.ack NOT counted in event_seqImplemented
packages/runtime/src/server.ts:SessionContext.dispatchRaw
Requirement
Status
Location
Feature flag list_jobs
Implemented
packages/core/src/version.ts:V1_1_FEATURES
session.list_jobs { filter?, limit?, cursor? } envelope with filter.status?, filter.agent?, filter.created_after?, filter.created_before?Implemented
packages/core/src/messages/session.ts:SessionListJobsPayloadSchema
session.jobs { request_id, jobs: JobListEntry[], next_cursor } responseImplemented
packages/core/src/messages/session.ts:SessionJobsPayloadSchema
JobListEntry { job_id, agent, status, lease, parent_job_id, created_at, trace_id, last_event_seq }Implemented
packages/core/src/messages/session.ts:JobListEntrySchema
Runtime echoes the request envelope's id as request_id
Implemented
packages/runtime/src/server.ts:handleListJobs
Authorization defaults to same-principal-only; broader policy via jobAuthorizationPolicy
Implemented
packages/runtime/src/server.ts:defaultJobAuthorizationPolicy + ARCPServerOptions.jobAuthorizationPolicy
Client listJobs(filter?, { limit?, cursor? })
Implemented
packages/client/src/client.ts:ARCPClient.listJobs
| Requirement | Status | Location |
| -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| Feature flag agent_versions | Implemented | packages/core/src/version.ts:V1_1_FEATURES |
| agent ::= name | name "@" versiongrammar (names lowercase[a-z0-9][a-z0-9._-]\*; versions [a-zA-Z0-9.+_-]+) | Implemented | packages/core/src/messages/execution.ts:parseAgentRef + formatAgentRef |
| Bare name resolves to the default version (or unversioned handler) | Implemented | packages/runtime/src/server.ts:ARCPServer.resolveAgent |
| name@version requires an exact match; otherwise AGENT_VERSION_NOT_AVAILABLE (session.error) | Implemented | packages/runtime/src/server.ts:handleJobSubmit (calls emitSessionError per §13.7) |
| Runtime advertises rich agent inventory when feature negotiated | Implemented | packages/runtime/src/server.ts:ARCPServer.getAgentInventory |
| job.accepted.payload.agent echoes the resolved name@version | Implemented | packages/runtime/src/job.ts:emitAccepted |
| Running job's version is fixed; never migrated | Implemented | packages/runtime/src/job.ts — agentVersion is readonly on the Job |
| Server APIs: registerAgent(name, fn), registerAgentVersion(name, version, fn), setDefaultAgentVersion(name, version) | Implemented | packages/runtime/src/server.ts:ARCPServer |
Requirement
Status
Location
Feature flag subscribe
Implemented
packages/core/src/version.ts:V1_1_FEATURES
job.subscribe { job_id, from_event_seq?, history? } envelopeImplemented
packages/core/src/messages/execution.ts:JobSubscribePayloadSchema
job.subscribed response carrying current_status, agent, lease, parent_job_id, trace_id, subscribed_from, replayedImplemented
packages/core/src/messages/execution.ts:JobSubscribedPayloadSchema
job.unsubscribe { job_id } envelopeImplemented
packages/core/src/messages/execution.ts:JobUnsubscribePayloadSchema
Same-principal scope by default; deployment policy can broaden
Implemented
packages/runtime/src/server.ts:defaultJobAuthorizationPolicy + jobAuthorizationPolicy hook
history: true replays buffered events; each replayed event uses the subscriber's event_seqImplemented
packages/runtime/src/server.ts:handleJobSubscribe + forwardEventToSubscriber (uses sub.nextEventSeq())
Live events fan out to all subscribers in addition to the owning session
Implemented
packages/runtime/src/server.ts:SessionContext.send fan-out block
Subscribers MUST NOT have cancel authority — only the submitting session may cancel
Implemented
packages/runtime/src/server.ts:handleJobCancel returns PERMISSION_DENIED when the session is a subscriber, not the submitter
Client subscribe(jobId, { history?, fromEventSeq? }) returning a handle with unsubscribe()
Implemented
packages/client/src/client.ts:ARCPClient.subscribe
Requirement
Status
Location
progress kind reservedImplemented
packages/core/src/messages/execution.ts:RESERVED_EVENT_KINDS
Body schema { current, total?, units?, message? }; current non-negative; total ≥ current recommended
Implemented
packages/core/src/messages/execution.ts:ProgressBodySchema
parseJobEventBody("progress", body) validates the bodyImplemented
packages/core/src/messages/execution.ts:parseJobEventBody
JobContext.progress(current, opts?) helperImplemented
packages/runtime/src/job.ts:makeJobContext
Requirement
Status
Location
Feature flag result_chunk
Implemented
packages/core/src/version.ts:V1_1_FEATURES
result_chunk kind reservedImplemented
packages/core/src/messages/execution.ts:RESERVED_EVENT_KINDS
Body schema { result_id, chunk_seq, data, encoding ∈ {utf8,base64}, more }
Implemented
packages/core/src/messages/execution.ts:ResultChunkBodySchema
job.result.payload.result_id / result_sizeImplemented
packages/core/src/messages/execution.ts:JobResultPayloadSchema
MUST NOT mix inline result and result_chunk in one job
Implemented
packages/runtime/src/job.ts:Job.emitResult enforces with InvalidRequestError
JobContext.streamResult({ resultId? }) writer (auto chunk_seq + terminal more:false + final job.result)Implemented
packages/runtime/src/job.ts:makeResultStream
JobContext.resultChunk(body) raw emitImplemented
packages/runtime/src/job.ts:makeJobContext
Client JobHandle.collectChunks() assembles chunks by result_id
Implemented
packages/client/src/client.ts:makeHandleFromInvocation
§9.4 Lease subsetting (v1.1 additions)
Requirement
Status
Location
Child cost.budget MUST NOT exceed parent's REMAINING budget per currency at delegation time
Implemented
packages/runtime/src/lease.ts:isLeaseSubset (numeric per-currency comparison; accepts parentBudgetRemaining Map)
Child lease_constraints.expires_at MUST NOT exceed parent's
Implemented
packages/runtime/src/lease.ts:assertLeaseConstraintsSubset
Child without lease_constraints inherits parent's expiry implicitly
Implemented
packages/runtime/src/server.ts:createDelegateJob (effectiveConstraints falls back to parent.leaseConstraints)
Requirement
Status
Location
Feature flag lease_expires_at
Implemented
packages/core/src/version.ts:V1_1_FEATURES
lease_constraints.expires_at on job.submit and job.accepted (ISO 8601 UTC with Z, MUST be future)Implemented
packages/core/src/messages/execution.ts:LeaseConstraintsSchema; runtime validation in packages/runtime/src/lease.ts:validateLeaseConstraints
Past or invalid values rejected with INVALID_REQUEST
Implemented
packages/runtime/src/lease.ts:validateLeaseConstraints
Operations attempted at or after expires_at MUST fail with LEASE_EXPIRED
Implemented
packages/runtime/src/lease.ts:validateLeaseOp (LeaseOpContext.constraints)
Runtime MUST emit job.error { final_status: "error", code: "LEASE_EXPIRED" } when the lease elapses while running
Implemented
packages/runtime/src/server.ts:runHandler (lease-expiry timer)
Renewal NOT supported
Implemented
No renewal API exists
validateLeaseOp accepts an optional now for clock injectionImplemented
packages/runtime/src/lease.ts:LeaseOpContext.now
Requirement
Status
Location
Feature flag cost.budget
Implemented
packages/core/src/version.ts:V1_1_FEATURES
cost.budget in RESERVED_CAPABILITY_NAMESImplemented
packages/core/src/messages/execution.ts:RESERVED_CAPABILITY_NAMES
Amount grammar currency:decimal (USD/EUR/credits/custom)
Implemented
packages/core/src/messages/execution.ts:parseBudgetAmount
validateLeaseShape rejects malformed budget patterns with INVALID_REQUESTImplemented
packages/runtime/src/lease.ts:validateLeaseShape
Initial per-currency counters initialized from the lease at job.accepted
Implemented
packages/runtime/src/lease.ts:initialBudgetFromLease; echoed in job.accepted.payload.budget via Job.emitAccepted
Counters decrement on metric events whose name starts with cost. and whose unit matches a budgeted currency
Implemented
packages/runtime/src/job.ts:Job.applyCostMetric + packages/runtime/src/server.ts:metricInterceptor
Negative metric values rejected (no decrement)
Implemented
packages/runtime/src/job.ts:Job.applyCostMetric
Operations fail with BUDGET_EXHAUSTED when a counter ≤ 0
Implemented
packages/runtime/src/lease.ts:validateLeaseOp
Runtime MAY emit cost.budget.remaining metric events with debounce
Implemented
packages/runtime/src/server.ts:metricInterceptor + Job.shouldEmitBudgetRemaining (5 % threshold)
JobContext.budget read-only snapshot of remaining countersImplemented
packages/runtime/src/job.ts:makeJobContext
§11 Trace attributes (v1.1 additions)
Requirement
Status
Location
arcp.lease.expires_at span attribute when presentImplemented
packages/middleware/otel/src/index.ts:extractAttributes
arcp.budget.remaining span attribute (encoded as JSON string for per-currency totals)Implemented
packages/middleware/otel/src/index.ts:extractAttributes
§12 Error taxonomy (v1.1 additions)
Code
Status
Location
AGENT_VERSION_NOT_AVAILABLEImplemented
packages/core/src/errors.ts:AgentVersionNotAvailableError
LEASE_EXPIREDImplemented
packages/core/src/errors.ts:LeaseExpiredError
BUDGET_EXHAUSTEDImplemented
packages/core/src/errors.ts:BudgetExhaustedError
All three are non-retryable by default
Implemented
Subclass constructors set retryable: false
The full canonical v1.1 set is 15 codes; see
packages/core/src/errors.ts:ERROR_CODES.
Item
Why
Effect
Persistent idempotency store
The runtime ships with an in-memory idempotencyStore and a 24-hour TTL sweep. v1.0/v1.1 mandate ~24h semantics but not persistence.
Restart drops cache. Production deployments override idempotencyTtlMs and/or swap in a persistent map.
Sandboxed lease enforcement
The SDK ships validateLeaseOp and expects the agent (or a runtime-wrapping shim) to call it.
Agent authors call validateLeaseOp(ctx.lease, capability, target, { constraints, budgetRemaining }).
INVALID_REQUEST on un-prefixed unknown capabilitiesWe enforce this strictly.
Consumers MUST stick to reserved namespaces or x-vendor.*.
Client-side proactive heartbeat ping
The client responds to runtime pings; it does not yet proactively ping when idle. The runtime's outbound ping covers the common dead-peer case.
Long-lived idle from the runtime side is still detected on the runtime's clock; symmetric client-side detection is a small follow-up.
All §4–§15 normative requirements for v1.0 are implemented as in
the previous CONFORMANCE.md.All v1.1 additions in §6.2 (features + rich agent inventory),
§6.4 (heartbeats), §6.5 (ack), §6.6 (list_jobs), §7.5 (versioning),
§7.6 (subscribe), §8.2 (progress), §8.4 (result streaming),
§9.4–§9.6 (lease constraints + budget), §11 (new span attrs), and
§12 (new error codes) are implemented as described above with
file:line citations.Each v1.1 feature is exercised by a dedicated example under
examples/ (heartbeat/, ack-backpressure/, list-jobs/,
subscribe/, agent-versions/, lease-expires-at/,
cost-budget/, progress/, result-chunk/). See
examples/README.md
The package set:
Package
Status
@arcp/coreImplemented (v1.1)
@arcp/clientImplemented (v1.1)
@arcp/runtimeImplemented (v1.1)
@arcp/sdkImplemented (v1.1)
@arcp/nodeImplemented
@arcp/expressImplemented
@arcp/fastifyImplemented
@arcp/honoImplemented
@arcp/bunImplemented
@arcp/middleware-otelImplemented (v1.1 attrs)