A RuntimePlan says how each executable node in a graph runs. It selects the run size and a default
harness and provider, and gives every step and verifier one binding. It contains model
identifiers and connection field names, never secret values.
Runtimes and connections explains the concepts, and
Build a review loop builds a complete plan for a custom graph. The Rust
types in openengine-cluster-protocol are authoritative; the
generated protocol schema is the
machine-readable contract.
RuntimePlan is a closed JSON object. All four fields are required, and unknown fields are rejected.
| Field | Value |
|---|---|
harness |
Harness of the default lane: codex, claude, or copilot |
provider |
Provider of the default lane, supported by the selected harness |
size |
small, medium, or large |
nodes |
Object mapping each executable graph node name to a node binding |
harness and provider form the default lane. Every agent node runs on it unless its binding
carries its own lane. size applies to the whole run. Model, effort, session
scope, and connections are chosen per node.
size is a run-level resource class. Zeroshot records it with the run and reports it in run
status; the hosting target decides what resources each class receives.
nodes keys are graph node names: 1 to 128 bytes matching [A-Za-z_][A-Za-z0-9_.-]*.
This plan binds the three agent nodes of the built-in software-change template:
{
"harness": "claude",
"provider": "anthropic",
"size": "medium",
"nodes": {
"worker": { "kind": "agent", "model": "PROVIDER_MODEL_ID", "sessionScope": "node_instance" },
"acceptance": { "kind": "agent", "model": "PROVIDER_MODEL_ID", "effort": "high" },
"code": { "kind": "agent", "model": "PROVIDER_MODEL_ID", "effort": "high" }
}
}harness selects which provider values parse:
harness |
provider |
|---|---|
codex |
openai, openrouter, bedrock, gateway |
claude |
anthropic, openrouter, bedrock, gateway |
copilot |
github |
The same pairs apply to an agent node's lane. Any other pair is rejected when
the plan is read.
kind selects one of two binding shapes. Fields that belong to the other kind are rejected.
| Field | Required | Value |
|---|---|---|
kind |
Yes | agent |
lane |
No | Harness and provider; default lane when omitted |
model |
Yes | Provider-owned model identifier, 1 to 2,048 non-control characters |
effort |
No | low, medium, high, xhigh, or max; unset when omitted |
sessionScope |
No | execution (default) or node_instance |
connections |
No | Connection declarations; empty when omitted |
Zeroshot passes model and effort to the harness unchanged. It keeps no model catalog and does not
check whether a model supports the chosen effort.
sessionScope controls provider conversation state. It does not change graph state or bindings.
sessionScope |
Behavior |
|---|---|
execution |
Opens a fresh provider session for each execution of the node, then closes it |
node_instance |
Reuses one session when the same node instance runs again, for example across loop iterations |
If a reused session is lost, Zeroshot fails that execution with session_lost. It does not open a
replacement session silently.
| Field | Required | Value |
|---|---|---|
kind |
Yes | git_delivery |
connections |
No | Connection declarations; empty when omitted |
pullRequestFeedback |
No | consider (default) or ignore |
A git_delivery binding has no model, effort, session scope, or lane. Admission accepts it only on
a verifier node whose worker is one of the built-in delivery workers:
| Worker | Accepts pullRequestFeedback: ignore |
|---|---|
builtin.git-delivery.push@1 |
No |
builtin.git-delivery.pr@1 |
No |
builtin.git-delivery.pr@2 |
Yes |
builtin.git-delivery.merge@1 |
No |
builtin.git-delivery.merge@2 |
No |
builtin.git-delivery.merge@3 |
Yes |
The delivery verifier cannot have authored instructions, must use attempts: 1, and must declare
the output, signals, and diagnostic of its worker's fixed contract. zeroshot template show software-change --pr prints a delivery node with the current contract.
A graph can contain at most one delivery node, and no other executable node may run in parallel with
it, either as a par sibling or inside a map that can have more than one item. A hosting service
may require exactly one delivery node; Zeroshot Cloud quick runs require one. See
concurrent workspace changes.
ignore skips pull-request discussion. CI, conflict, freshness, and merge-policy checks still apply.
A lane is one harness and provider pair. The plan's harness and provider are the default lane
for every agent node, and an agent binding can carry its own lane. A node's effective lane is
its lane, or the default lane when it has none. size stays run-level.
This plan binds the same three nodes as the first example. worker runs
on the default codex/openai lane, and both reviewers run on Claude Code:
{
"harness": "codex",
"provider": "openai",
"size": "medium",
"nodes": {
"worker": { "kind": "agent", "model": "PROVIDER_MODEL_ID", "sessionScope": "node_instance" },
"acceptance": {
"kind": "agent",
"lane": { "harness": "claude", "provider": "anthropic" },
"model": "PROVIDER_MODEL_ID",
"effort": "high"
},
"code": {
"kind": "agent",
"lane": { "harness": "claude", "provider": "anthropic" },
"model": "PROVIDER_MODEL_ID",
"effort": "high"
}
}
}Each model goes to the provider of its node's effective lane, so here worker needs an OpenAI
model identifier and the reviewers need Anthropic ones.
laneaccepts the same pairs as the run level, listed in Harness and provider. An invalid pair is rejected when the plan is read.- A
git_deliverybinding cannot carry alane. - A
laneequal to the run-level pair is accepted, and the node runs exactly as it would without one. It is still alanefield, so the target support check applies to it and older binaries reject it. Omitlanewhen a node should use the default lane.
Zeroshot starts one harness adapter for each distinct effective lane, and each node runs on its own lane's CLI. Model, effort, session scope, and connections stay per node. Provider access defaults also come from each node's effective lane; see Connections.
Targets that support lanes advertise openengine.node-runtime-lanes/v1 in their discovery
document. Before the CLI submits a run or stores a profile on a target, it checks the plan. If any
node carries a lane and the target does not advertise the capability, the command fails after
reading the target's discovery document and before it requests an access token or sends the plan:
target operation failed: target does not support per-node runtime lanes (openengine.node-runtime-lanes/v1)
Plans without a lane are unchanged on the wire and work with every target. Older Zeroshot
binaries reject a plan that contains a lane field when they read it.
Local profiles are saved together in one file in the configuration store (ZEROSHOT_CONFIG_DIR).
Once any local profile carries a lane, an older binary cannot read that file at all. Every local
profile command, --profile local:NAME run, and zeroshot acp session then fails, including for
profiles without lanes:
local controller operation failed: local profile store is malformed
To run an older binary beside a newer one, give it its own ZEROSHOT_CONFIG_DIR. To recover, remove
the profile or its lane fields with the newer binary.
Before the controller starts, a local zeroshot run or zeroshot resume checks that each lane's
executable, codex, claude, or copilot, is on PATH. A missing executable fails the command
with a message such as:
lane claude/anthropic needs the `claude` executable on PATH
zeroshot acp runs the same check when each session opens, against that session's workspace, and
the session request fails with the same message. When every PATH entry is absolute, it also
checks at startup. An empty or relative entry resolves against the directory the harness starts in,
which is known only per session, so then the startup check is skipped. The check does not inspect login state; a missing login surfaces at
that lane's first turn. As in a single-lane run, local codex/openai, claude/anthropic, and
copilot/github lanes reuse their harness's native login, and other lanes need their provider's
connection fields; see Connections.
nodes contains exactly one binding for every step and verifier in the graph, keyed by the node
name. Structural nodes (seq, choice, par, loop, map) and terminal nodes (succeed,
fail) never get a binding. Admission rejects:
- a missing binding for an executable node;
- a binding for a structural, terminal, or unknown node;
- a
git_deliverybinding on astep, or on a verifier that does not use a delivery worker; - an
agentbinding on a node that uses a delivery worker; - an
agentbinding on a node without authoredinstructions; - a worker reference reused on several nodes with a different contract or binding kind.
connections maps a connection key to the exact environment field names the node may receive.
Values come from the submission environment or a target connection store at run time.
{
"connections": {
"gateway": ["GATEWAY_BASE_URL", "GATEWAY_API_KEY"]
}
}| Item | Limit |
|---|---|
| Connection key | 1 to 128 bytes, no control characters |
| Field name | [A-Za-z_][A-Za-z0-9_]*, at most 128 bytes |
| Field list | At least one name, no duplicates |
| Keys per node | At most 64 |
| Field names per node | At most 64, and one name cannot appear under two keys in the same node |
| Unique field names per run | At most 64 across all nodes |
The per-run limit also counts the connection fields and variable names of an attached runtime environment. Each connection value must be 1 byte to 64 KiB with no NUL. The static connection values supplied for one run, counting each key and field name with its value, must fit in 256 KiB.
When a node omits connections, Zeroshot derives provider access from that node's
effective lane for the execution placement. Local native logins need no
declaration; contained targets and non-native providers receive the canonical requirements listed in
Runtimes and connections.
A run's connection requirements are the union over its nodes, so a plan that mixes lanes can require
the fields of several providers.
--uniform-runtime-config accepts a single agent configuration and expands it into a full plan:
| Field | Required | Value |
|---|---|---|
harness |
Yes | As in RuntimePlan |
provider |
Yes | As in RuntimePlan |
size |
No | As in RuntimePlan; default medium |
model |
Yes | As in an agent binding |
effort |
No | As in an agent binding |
sessionScope |
No | As in an agent binding |
connections |
No | Applied to every agent node |
Every executable node gets an agent binding with these values, except nodes that use a delivery
worker. Those get a git_delivery binding as described below.
When selecting the built-in software-change template, omitted sessionScope defaults to
node_instance for worker and execution for its reviewers. The worker retains its session
through implementation and every repair; reviewers start fresh each pass. An explicit uniform
sessionScope still applies to every agent. Exact runtime plans and saved graphs retain their
authored scopes; use node_instance on worker in an exact plan to retain its session.
When using the updated template with an older exact runtime config, remove its review_repair
and delivery_repair bindings. Existing saved profiles keep their stored graph and bindings.
A uniform configuration applies one lane to every agent node. Neither --uniform-runtime-config nor
the Python SDK's UniformRuntime can express per-node lanes; use an exact
--runtime-config or an opaque RuntimePlan instead.
Built-in templates own their delivery nodes. With software-change, --push, --pr, and --ship
add a delivery verifier named deliver. The existing worker handles delivery repairs. With auto-research, --push
adds checkpoint_delivery plus the agent nodes checkpoint_manifest and checkpoint_audit.
single-worker has no delivery modes.
The CLI inserts a git_delivery binding with no forge connection for push, or
{"github": ["GH_TOKEN"]} for PR and merge. Git transport uses the selected
source credentials.
--no-pr-feedback (requires --pr or --ship) sets pullRequestFeedback to ignore.
A uniform configuration binds the added agent nodes too. An exact --runtime-config must bind
all agent nodes itself. Software-change uses worker, acceptance, and code with every delivery
mode. It may omit the delivery node; if it includes it, the binding must be git_delivery. List the executable nodes
with zeroshot template show TEMPLATE plus the same delivery flag.
Custom graphs author delivery in both the graph and the plan.