openclaw - 💡(How to fix) Fix [Bug]: 2026.4.25 — heartbeat.model override ignored; heartbeat runs on session primary then falls back to gpt-5 [2 comments, 3 participants]

Bug type

Regression (worked before, now fails)

Beta release blocker

No

Summary

After upgrading to 2026.4.25, the heartbeat.model override is silently ignored. Heartbeat runs on openai/gpt-5 (the first fallback) instead of the configured openrouter/anthropic/claude-haiku-4.5.

Config (unchanged from 2026.4.23 where it worked correctly):

"heartbeat": {
  "every": "90m",
  "isolatedSession": true,
  "lightContext": true,
  "model": "openrouter/anthropic/claude-haiku-4.5",
  "activeHours": {
    "start": "08:30",
    "end": "22:30",
    "timezone": "America/Los_Angeles"
  }
}

agents.defaults.model (session primary and fallbacks):

"model": {
  "primary": "openrouter/anthropic/claude-sonnet-4.6",
  "fallbacks": [
    "openai/gpt-5",
    "openai/gpt-5-mini"
  ]
}

Steps to reproduce

1. Configure agents.defaults.heartbeat.model to a different model than agents.defaults.model.primary
2. Configure agents.defaults.model.fallbacks with openai/gpt-5 as first fallback
3. Upgrade to 2026.4.25
4. Wait for heartbeat to fire
5. Observe openclaw status — heartbeat session shows gpt-5 instead of configured Haiku model

Expected: Heartbeat runs on openrouter/anthropic/claude-haiku-4.5 as configured.

Actual: Heartbeat runs on openai/gpt-5 (first fallback). The model override is silently dropped.

Additional observations:

• Token count jumped from ~9.6k to 37k suggesting lightContext: true and isolatedSession: true are also not being honored
• This worked correctly on 2026.4.23 — regression introduced in 2026.4.24 or 2026.4.25
• Clearing the heartbeat session file and sessions.json entry did not resolve the issue

Related issues: #58137 (heartbeat model override ignored, force-switched to main session model — reported on 2026.3.28, apparently not fully resolved)

Expected behavior

Heartbeat runs on openrouter/anthropic/claude-haiku-4.5 as configured.

Actual behavior

Heartbeat runs on openai/gpt-5 (first fallback). The model override is silently dropped.

openclaw status shows the heartbeat session running on gpt-5:

│ agent:main:main:heartbeat │ direct │ 6m ago │ gpt-5 │ 37k/400k (9%) · 51% cached │

Token count also indicates lightContext: true and isolatedSession: true are not being honored — 37k tokens vs ~9.6k before the upgrade.

The agent itself (queried via Telegram) confirmed no heartbeat model override is visible in the active session: "The active model is Claude Sonnet 4.6. That's what the next heartbeat would run on — same model, no override set."

OpenClaw version

2026.4.25 (aa36ee6)

Operating system

Linux Mint, linux 6.8.0-110-generic x64, node 24.14.1

Install method

npm global via openclaw update

Model

openrouter/claude-sonnet-4.5

Provider / routing chain

openrouter

Additional provider/model setup details

Upgraded from: 2026.4.24 (issue not present on 2026.4.23 — heartbeat was correctly using Haiku)

Logs, screenshots, and evidence

Impact and severity

No response

Additional information

No response