Fleet task ' ' metadata.coordination_contracts accepts at…

Error message

Fleet task '{}' metadata.coordination_contracts accepts at most 16 entries

What it means

fleet_coordination_contracts enforces a hard bound of 16 coordination contract entries per Fleet task. A metadata.coordination_contracts array longer than 16 is rejected to keep worker coordination claims bounded and reviewable.

Solutions

Consolidate contracts into fewer, broader entries (e.g. one shared-resource lease instead of many).
Split the work across multiple Fleet tasks with at most 16 contracts each.
Deduplicate repeated contract strings in the metadata producer.
Move overflow coordination to a coordinating manager task rather than per-worker contracts.

Example fix

// before: 20 contract entries in one task
// after: dedupe/split
"coordination_contracts": ["lease:db", "lease:api", "lock:idx"] // <= 16

Defensive patterns

Strategy: validation

Validate before calling

if (contracts.length > 16) throw new Error(`coordination_contracts accepts at most 16 entries (got ${contracts.length})`);

Prevention

Cap contract generation at 16 entries per task.
Deduplicate contracts before writing metadata.
Split oversized coordination sets across multiple tasks.

When it happens

Trigger: fleet_task_to_worker_spec_with_profiles -> fleet_coordination_contracts where task_spec.metadata["coordination_contracts"] is a valid array of strings but values.len() > 16.

Common situations: Generating task specs from a script that appends every shared resource as a contract; bulk-converted legacy configs listing dozens of leases; template expansion duplicating contract entries.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/34a9725656af9094. Report an issue: GitHub.

Appendix: source

Thrown at crates/tui/src/fleet/worker_runtime.rs:598

    Ok(if segments.is_empty() {
        ".".to_string()
    } else {
        segments.join("/")
    })
}

fn fleet_coordination_contracts(task_spec: &FleetTaskSpec) -> Result<Vec<String>> {
    let Some(value) = task_spec.metadata.get("coordination_contracts") else {
        return Ok(Vec::new());
    };
    let Some(values) = value.as_array() else {
        bail!(
            "Fleet task '{}' metadata.coordination_contracts must be an array of strings",
            task_spec.id
        );
    };
    if values.len() > 16 {
        bail!(
            "Fleet task '{}' metadata.coordination_contracts accepts at most 16 entries",
            task_spec.id
        );
    }
    let mut contracts = Vec::new();
    for value in values {
        let Some(value) = value.as_str() else {
            bail!(
                "Fleet task '{}' metadata.coordination_contracts must contain only strings",
                task_spec.id
            );
        };
        let value = value.trim();
        if value.is_empty()
            || value.chars().count() > 128
            || value.chars().any(|ch| matches!(ch, '\0' | '\r' | '\n'))
        {
            bail!(

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