Summary

config.patch (and the underlying config validator) rejects agents.defaults.compaction.model, agents.defaults.compaction.customInstructions, and agents.defaults.compaction.postCompactionSections as "Unrecognized key" — even though:

1. config.schema.lookup returns full schema entries with type, hint label, and help text for all three
2. The runtime schema file (dist/runtime-schema-*.js) defines all three keys
3. The configuration reference docs documents all three with examples
4. The 2026.4.2 changelog explicitly mentions compaction.model resolution (fix(compaction): resolve model override in runtime context for all context engines #56710)

Reproduction

openclaw --version
# OpenClaw 2026.4.2 (d74a122)

# Schema says it's valid:
openclaw config schema --path agents.defaults.compaction.model
# Returns: { type: "string", hint: { label: "Compaction Model Override", ... } }

# But config.patch rejects it:
# config.patch path=agents.defaults.compaction raw={"model":"anthropic/claude-sonnet-4-6"}
# Error: invalid config: <root>: Unrecognized key: "model"

Same rejection for customInstructions and postCompactionSections.

Root Cause (suspected)

The config validator likely uses a Zod/JSON-Schema with additionalProperties: false on the compaction object, and the newer keys were added to the hint registry and runtime schema but not to the validator's allowlist.

Workaround

Direct file edit of openclaw.json + SIGUSR1 restart. The gateway loads and uses the keys correctly — it's only the write-time validator that rejects them.

Environment

• OpenClaw 2026.4.2 (d74a122)
• macOS Tahoe (arm64)
• Node 25.8.2
• Affects both config.patch tool and presumably openclaw config set CLI