How to use EXECUTION.pipeline for agent routing, classification, and short-circuiting

Back to how-to guides Use EXECUTION.pipeline when a supervisor or routing agent needs a fast classification pass that can route obvious single-intent requests before the normal reasoning path runs.

Concept

EXECUTION.pipeline is the agent execution pipeline. It is not a Knowledge Base ingestion pipeline, a custom operational pipeline, or a workflow. It runs before the reasoning loop. A classifier model reads the user message and assigns one or more intent categories. The runtime then resolves each category to a route with your HANDOFF or DELEGATE conditions. The pipeline has four parts:

Part	What it does
Classifier	Assigns an intent category and a confidence score to the message.
Short-circuit	Routes a confident single-intent request without a reasoning turn.
Keyword veto	Blocks short-circuiting when the message contains a sensitive word.
Intent bridge	Guides reasoning when the classifier is not confident enough to route.

Use the pipeline when routing quality or latency depends on a fast classification pass. Do not use it for durable waits, approvals, schedules, or long-running work. Use workflows for those.

Requirements

The pipeline runs only when all of these are true:

The project enables it. In Studio, open the project Runtime Config and turn on Enable Pipeline in the Reasoning Pipeline section. Studio labels this feature experimental.
The agent does not opt out. enabled: false in the agent EXECUTION.pipeline block turns it off for that agent even when the project enables it.
The agent has route conditions that use intent.category, or the agent declares INTENTS. Without categories, the classifier does not run.
A pipeline model is available. The default model source uses the tool_selection model of the project. Without a model, the pipeline skips the classifier.

enabled: true in ABL does not enable the pipeline when the project setting is off.

Minimal working example

The supervisor declares its categories in INTENTS and routes each category with intent.category. The classifier chooses from the INTENTS list.

SUPERVISOR: Support_Router
GOAL: "Route support requests using classifier-assisted pipeline decisions"
PERSONA: "Concise support routing supervisor"

LIMITATIONS:
  - "Cannot answer questions unrelated to billing or technical support"

INTENTS:
  billing: "Questions about invoices, balances, billing errors, refunds, or payments."
  technical_support: "Problems with device setup, errors, troubleshooting, or service outage."
  general: "Requests that are unclear or do not fit billing or technical support."

EXECUTION:
  pipeline:
    enabled: true
    mode: sequential
    shortCircuit:
      enabled: true
      confidenceThreshold: 0.9
    keywordVeto:
      enabled: true
      keywords: ["refund", "cancel", "fraud"]
    intentBridge:
      enabled: true
      programmaticThreshold: 0.85
      guidedThreshold: 0.5
      outOfScopeDecline: true
      multiIntentSignal: true

HANDOFF:
  - TO: Billing_Agent
    WHEN: intent.category == "billing"
    SUMMARY: "User needs billing support"
  - TO: Technical_Support_Agent
    WHEN: intent.category == "technical_support"
    SUMMARY: "User needs technical support"
  - TO: General_Fallback_Agent
    WHEN: intent.category == "general"
    SUMMARY: "User needs clarification or general support"

AGENT: Billing_Agent
GOAL: "Resolve billing, invoice, refund, and payment questions"
PERSONA: "Billing specialist"

AGENT: Technical_Support_Agent
GOAL: "Troubleshoot device, software, and service issues"
PERSONA: "Technical support specialist"

AGENT: General_Fallback_Agent
GOAL: "Clarify unclear support requests and route users to the right next step"
PERSONA: "General support specialist"

The pipeline resolves routes with the intent.category condition. A quoted plain-language WHEN sentence does not select a route in the pipeline. Use intent.category conditions for any route you want the pipeline to choose. The classifier model is not set in ABL. Select it in the project Runtime Config under Pipeline Model. The model field in EXECUTION.pipeline has no effect.

How it works

For each user message, the runtime follows this order:

The classifier assigns each intent a category and a confidence score. The classifier sees the current message and the last four conversation messages. The runtime redacts PII before it sends them.
The runtime resolves each category to a route. The first matching WHEN condition, in priority order, selects the target.
The runtime checks whether to short-circuit.
If the runtime does not short-circuit, the intent bridge picks a tier.

Short-circuit

A single-route short-circuit happens only when all of these are true:

shortCircuit.enabled is true. This is the default.
The classifier returns one intent with a category.
The confidence is at or above shortCircuit.confidenceThreshold. The default is 0.85.
The category resolves to exactly one route target.
No veto word appears in the message.

When these conditions hold, the runtime hands off to the target (or runs the delegate) without a reasoning turn.

Keyword veto

Keyword veto matches whole words, ignoring case. The veto list has two sources:

The words in keywordVeto.keywords.
The words in the names of the agent tools, split on underscores. Parts shorter than three characters are ignored. A tool named process_refund vetoes the words process and refund.

Handoff and delegate tools do not add veto words. Review tool names when short-circuiting stops working for common words.

Intent bridge tiers

The intent bridge acts when the runtime does not short-circuit.

Tier	Condition	Behavior
Programmatic	Every intent is out of scope, confidence is at or above `programmaticThreshold`, `outOfScopeDecline` is `true`, and the agent declares `LIMITATIONS`.	The agent declines with the `out_of_scope` message. Agents reached by a handoff skip the decline.
Guided	Confidence is at or above `guidedThreshold`.	Reasoning runs with hints. The runtime hides handoff tools for unmatched targets and adds a routing hint. Escalation targets are never hidden.
Autonomous	No result, no intents, or confidence below `guidedThreshold`.	Normal reasoning decides.

programmaticThreshold controls only the out-of-scope decline. Route short-circuiting uses shortCircuit.confidenceThreshold.

Multiple intents

When the classifier finds two or more requests, no single-route short-circuit happens. With multiIntentSignal on, the guided tier adds a multi-intent hint. When MULTI_INTENT and intentBridge are enabled, every request resolves to a target, and every confidence is at or above the short-circuit threshold, the runtime runs a multi-intent plan. Independent requests run in parallel. Dependent requests run in sequence. See How to handle multiple intents in one user message.

Failure behavior

If the classifier call fails or returns no usable result, the turn continues in autonomous reasoning. The runtime records a pipeline_classifier_unavailable trace event.
After three consecutive pipeline failures for a tenant, a circuit breaker bypasses the pipeline for 60 seconds.
If no category resolves to a route, the supervisor reasons normally.

Since none of the HANDOFF entries above declare HISTORY, each specialist receives the full conversation history by default (the current platform default when HISTORY is omitted).

Common variations

Fast single-intent routing

Enable shortCircuit for high-volume routers where users usually ask one clear thing, such as “What is my balance?” or “My device will not start.”

Sensitive keyword veto

Add words to keywordVeto.keywords when they must never short-circuit. A vetoed message goes to the guided tier, where the supervisor reasons about the route.

Multi-intent detection

Enable multiIntentSignal when users often ask for more than one thing, such as “Cancel my subscription and refund my last payment.”

Out-of-scope decline

Set outOfScopeDecline: true and declare LIMITATIONS when the agent must decline requests outside its scope without a reasoning turn.

Classifier without short-circuit

Set shortCircuit.enabled: false to keep the classifier and intent bridge but let the model make every routing decision.

Verification

Send a clear single-intent message, such as “Where is my invoice?”. Confirm a pipeline_classify event with the billing category and a handoff to Billing_Agent without a reasoning turn.
Send a vague message. Confirm a pipeline_tiered_action event with the guided or autonomous tier and no short-circuit.
Send a message with two requests. Confirm two intents in pipeline_classify and no single-route short-circuit.
Send a message with a veto word, such as “I want a refund”. Confirm a confident pipeline_classify result and no short-circuit.
Send an unrelated message. Confirm a pipeline_tiered_action event with the decline_out_of_scope action.
Check pipeline_routing_resolve to confirm each category resolved to the expected target.
Confirm the specialist receives the expected summary and conversation history.

See How to debug routing with traces for how to read routing traces.

Production readiness checklist

Enable the pipeline in the project Runtime Config and select a pipeline model.
Categories are distinct, and every category maps to one route.
A fallback category and target exist for unclear and unsupported requests.
The agent declares LIMITATIONS if you rely on out-of-scope decline.
Thresholds are tested against real utterances.
Product, support, and compliance owners review the veto words.
Tool names do not contain common words that veto short-circuiting.
Dashboards track classifier confidence, short-circuit rate, veto rate, fallback rate, and misroutes.

Common mistakes

Mistake	Why it happens	How to avoid it
Treating `EXECUTION.pipeline` as a workflow	Both use the word pipeline	Use workflows for durable orchestration. Use `EXECUTION.pipeline` for agent routing.
Routing with quoted plain-language `WHEN` text	The text reads like a rule	Use `INTENTS` and `intent.category` conditions for pipeline routes.
Setting `model` in `EXECUTION.pipeline`	The field parses without error	Select the pipeline model in the project Runtime Config.
Expecting `enabled: true` to turn the pipeline on	Agent config looks complete	Enable the pipeline in the project Runtime Config.
Setting `programmaticThreshold` to tune routing	The name suggests direct routing	Tune `shortCircuit.confidenceThreshold` for routing.
Expecting a decline without `LIMITATIONS`	`outOfScopeDecline` is on	Declare `LIMITATIONS` on the agent.
Missing fallback route	The classifier cannot always match	Add a fallback category and target. Test no-match requests.

Troubleshooting

Symptom	Likely cause	What to check
Pipeline config compiles but nothing runs	The project setting is off, the agent opts out, or no pipeline model exists	Check the project Runtime Config and the agent `enabled` value.
No `pipeline_classify` event	The agent has no categories or routes, or the circuit breaker is open	Check `INTENTS`, route conditions, and recent classifier failures.
Obvious request does not short-circuit	Confidence is below the threshold, there are several intents, the category is null, a veto word matched, or the category matches no route	Inspect the `pipeline_classify` and `pipeline_routing_resolve` events.
Common word blocks short-circuiting	A tool name contains the word	Rename the tool or accept the veto.
Every request goes to the first route	The route `WHEN` uses plain-language text	Switch to `intent.category` conditions.
Sensitive request routes too fast	Keyword veto is off or the word is missing	Add the word to `keywordVeto.keywords`.
Classifier returns a category you did not define	The classifier drifts	The runtime drops unknown categories. Confirm `INTENTS` and the fallback route.
Decline never happens	The agent has no `LIMITATIONS`, confidence is below `programmaticThreshold`, or a handoff reached the agent	Check `LIMITATIONS` and the `pipeline_tiered_action` event.

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References

How to use EXECUTION.pipeline for agent routing, classification, and short-circuiting

Concept

Requirements

Minimal working example

How it works

Short-circuit

Keyword veto

Intent bridge tiers

Multiple intents

Failure behavior

Common variations

Fast single-intent routing

Sensitive keyword veto

Multi-intent detection

Out-of-scope decline

Classifier without short-circuit

Verification

Production readiness checklist

Common mistakes

Troubleshooting

​Concept

​Requirements

​Minimal working example

​How it works

​Short-circuit

​Keyword veto

​Intent bridge tiers

​Multiple intents

​Failure behavior

​Common variations

​Fast single-intent routing

​Sensitive keyword veto

​Multi-intent detection

​Out-of-scope decline

​Classifier without short-circuit

​Verification

​Production readiness checklist

​Common mistakes

​Troubleshooting

Concept

Requirements

Minimal working example

How it works

Short-circuit

Keyword veto

Intent bridge tiers

Multiple intents

Failure behavior

Common variations

Fast single-intent routing

Sensitive keyword veto

Multi-intent detection

Out-of-scope decline

Classifier without short-circuit

Verification

Production readiness checklist

Common mistakes

Troubleshooting