Hermes Model Switching

Hermes Model Switching & Cross-Provider Routing

When to Use

• Starting a session and want to pick the right provider for the task
• Gemini or Codex credits are underutilized (check weekly)
• Need to quickly switch Hermes between providers from command line
• Auditing how stale utilization tracking data is
• Assigning overnight batch tasks across providers

Quick Switch (Shell Aliases)

Installed in ~/.bash_aliases (updated 2026-04-09).

h              # hermes chat (default = config-driven; keep Codex-first)
h-codex        # gpt-5.4 via openai-codex
h-gpt          # same as h-codex
h-mini         # gpt-5.4-mini via openai-codex
h-batch        # gpt-5.2 via openai-codex

h-opus         # Codex-opus-4-6 via Anthropic (explicit use)
h-sonnet       # Codex-sonnet-4-6 via Anthropic (explicit use)

h-gemini       # gemini-2.5-pro via Google AI Studio direct (explicit use)
h-gemini-flash # gemini-2.5-flash via Google AI Studio direct (explicit use)
h-router-gemini # google/gemini-2.5-pro via OpenRouter (explicit use)

h-router       # qwen/qwen3.6-plus:free via OpenRouter (explicit use)
h-qwen         # same as h-router
h-nemotron     # nvidia/nemotron-3-super-120b-a12b:free via OpenRouter

h-copilot      # Codex-sonnet-4.6 via Copilot (explicit use)
h-copilot-gemini # gemini-2.5-pro via Copilot (explicit use)
h-copilot-gpt  # gpt-5.4 via Copilot (explicit use)

h-o3           # o3 via OpenAI
h-which        # show current model block from ~/.hermes/config.yaml
h-quick        # show quick_commands block from ~/.hermes/config.yaml

Policy note: Gemini and Copilot remain available, but they are explicit-use only and should not be described or treated as automatic fallback/default routing.

NOTE: h-gemini and h-gemini-flash aliases exist but use --provider google which is NOT a valid Hermes CLI provider. Use h-copilot-gemini for Gemini via Copilot quota, OR use the direct AI Studio path below to route through your $20/mo Gemini sub instead.

Gemini via AI Studio Direct API (uses $20/mo Gemini sub, not Copilot quota)

Google AI Studio exposes an OpenAI-compatible endpoint. Hermes can reach it via the openrouter provider with a custom --base-url. GEMINI_API_KEY in ~/.hermes/.env (scanner-allow:hermes_env_access — doc reference, not an instruction to read secrets) is NOT auto-detected by any provider — it must be passed explicitly.

Test first:

hermes chat --provider openrouter \
  --api-key $GEMINI_API_KEY \
  --base-url https://generativelanguage.googleapis.com/v1beta/openai/ \
  -m gemini-2.5-pro \
  -e "say hello in 5 words"

If that works, add aliases to ~/.bash_aliases:

alias h-gemini='hermes chat --provider openrouter --api-key $GEMINI_API_KEY --base-url https://generativelanguage.googleapis.com/v1beta/openai/ -m gemini-2.5-pro'
alias h-gemini-flash='hermes chat --provider openrouter --api-key $GEMINI_API_KEY --base-url https://generativelanguage.googleapis.com/v1beta/openai/ -m gemini-2.5-flash'

Then reload: source ~/.bash_aliases

Pitfall: GEMINI_API_KEY must be set in the shell environment (loaded from .env) for the $GEMINI_API_KEY expansion to work in the alias. Verify with: echo $GEMINI_API_KEY

Other Switching Methods

1. In-session: /model deepseek:deepseek-chat or /model copilot:gemini-2.5-pro
2. Persistent config: hermes config set model.default <model> && hermes config set model.provider <provider>
3. Per-session flag: hermes chat -m <model> --provider <provider>
4. Interactive wizard: hermes model (TUI picker — slowest method)

Hermes --provider CLI Choices (HARDCODED — pitfall!)

Valid --provider values: auto, openrouter, nous, openai-codex, copilot-acp, copilot, anthropic, huggingface, zai, kimi-coding, minimax, minimax-cn, kilocode, deepseek

DeepSeek was missing from the hardcoded argparse choices in hermes_cli/main.py despite being in the auth registry. Patched on 2026-04-04 (line ~4041). If Hermes updates overwrite this, re-patch or use /model deepseek:deepseek-chat in-session instead.

Gemini is now a valid Hermes CLI provider (hermes chat --provider gemini ...). However, observed on 2026-04-09 that direct Gemini calls returned HTTP 429 free-tier quota exhaustion (generate_content_free_tier_requests) and Hermes then auto-fell back to Copilot, which was also exhausted. So Gemini should not be used as Hermes automatic cheap/default routing until quota behavior is stabilized.

Horses-for-Courses Task Routing

Reality Check (cross-agent audit 2026-04-02)

Config claims vs actual usage — routing must be actively enforced:

• Codex: 95.5% of all work (must actively push tasks to other providers)
• Codex: 99.8% review only, 0% implementation despite config claims
• Gemini: 100% review only, 0% research despite 1M context advantage
• Hermes: 2nd most active agent but absent from routing-config.yaml

Utilization Data Audit Pattern

When asked about utilization, check these sources in order:

Critical gap: No automated Codex or Gemini spend tracking. No cron job refreshes any quota data. See #1855.

Hermes Config (updated 2026-04-09 — Codex-first, no automatic Gemini/Copilot routing)

REASON: repeated Gemini 429 quota exhaustion and Copilot fallback exhaustion caused retry waste and stale-session confusion. Current baseline is Codex-first with smart routing disabled and automatic fallback disabled.

Available Codex Models (as of 2026-04-08)

model:
  default: gpt-5.4
  provider: openai-codex
  base_url: https://chatgpt.com/backend-api/codex
fallback_providers: []
fallback_model: {}
credential_pool_strategies:
  openai-codex: round_robin
  anthropic: fallback
smart_model_routing:
  enabled: false
  cheap_model:
    provider: openai-codex
    model: gpt-5.4-mini
quick_commands:
  research: { provider: openai-codex, model: gpt-5.4-mini }
  code:     { provider: openai-codex, model: gpt-5.4 }
  review:   { provider: openai-codex, model: gpt-5.4 }
  quick:    { provider: openai-codex, model: gpt-5.4-mini }
  data:     { provider: openai-codex, model: gpt-5.4-mini }
  batch:    { provider: openai-codex, model: gpt-5.2 }
delegation:
  model: gpt-5.4
  provider: openai-codex

Routing Tiers (clean baseline — as of 2026-04-09)

DEFAULT:   openai-codex/gpt-5.4
QUICK:     openai-codex/gpt-5.4-mini
BATCH:     openai-codex/gpt-5.2
FALLBACK:  disabled
SMART ROUTING: disabled

Important runtime nuance:

• config edits do NOT repair an already-running session whose primary runtime was originally Gemini/Copilot
• run_agent.py restores the original primary runtime at the start of each new turn in long-lived sessions
• if logs show Primary runtime restored for new turn: gemini..., restart the long-lived Hermes process/session; config alone is not enough

To use Codex explicitly: h-opus, h-sonnet, h-copilot To use Gemini explicitly: h-copilot-gemini, h-gemini, h-router-gemini

Credential Pool (as of 2026-04-04)

anthropic:    2 creds (hermes_pkce + Codex OAuth)
openai-codex: 2 creds (both $20/mo subs pooled, round-robin)
copilot:      1 cred  (GH_TOKEN from gh auth token)
deepseek:     1 cred  (DEEPSEEK_API_KEY in .env)
openrouter:   1 cred  (OPENROUTER_API_KEY in .env — added 2026-04-04)
gemini-direct: n/a    (GEMINI_API_KEY in .env — used via openrouter provider + custom base-url)

Add more Codex accounts: hermes auth add openai-codex → OAuth device flow. View pool: hermes auth list. Reset exhaustion: hermes auth reset <provider>.

Config Pitfall: Provider-Model Mismatch

If default provider is openai-codex but delegation.model is Codex-sonnet-4-6, subagents try Codex on Codex endpoint → fails. Always set delegation.provider explicitly.

Similarly, if default is openai-codex and you run hermes chat --provider nous, it sends the default model name gpt-5.4 to Nous — which Nous routes through their paid gateway, burning Nous credits instead of using a free model. Always specify BOTH --provider AND -m when switching.

Config Mismatch Warning

If default provider is openai-codex but delegation.model is Codex-sonnet-4-6, subagents will try to run a Codex model on the Codex endpoint — which fails. Always set delegation.provider explicitly when it differs from the default.

Subscription Economics (Critical Context)

ALL providers use subscription billing — NOT pay-per-token API:

• Codex Max: $200/mo (CLI OAuth via ~/.Codex/.credentials.json)
• OpenAI x2: $40/mo ($20 each, subscription)
• Gemini Pro: $20/mo (Google login)
• GitHub Copilot: $9/mo ($107/yr annual)
• Total: ~$269/mo FIXED — cost doesn't change with usage volume

Hermes authenticates to Codex via read_claude_code_credentials() which reads the Codex OAuth token. No separate API key needed — the ANTHROPIC_API_KEY in ~/.hermes/.env is empty/unused. (scanner-allow:hermes_env_access — doc reference, not an instruction to read secrets)

Optimization is about maximizing VALUE from fixed spend, not reducing cost per token. Every unused Gemini query slot is capacity already paid for but wasted.

Gemini as Advance Scout Pattern

Gemini should run FIRST to prepare context for Codex/Codex coding:

1. Research before coding — APIs, standards, libraries → write to notes/prep/
2. Large document ingestion — 1M context for specs/PDFs → structured extracts
3. Codebase recon — scan repos, map deps → recon reports
4. Standards mapping — map functions to API/DNV/ISO standards (zero coding)
5. Issue triage prep — scan new issues, draft approach notes
6. Test data generation — fixtures, mock data for upcoming TDD work

Simple dispatch pattern:

# Gemini preps, Codex implements:
h-gemini "Research [topic]. Write findings to /tmp/prep-notes.md"
h-opus "Read /tmp/prep-notes.md. Implement [feature] based on the research."

Subagent Delegation Config

In ~/.hermes/config.yaml, set delegation model to Sonnet (applied 2026-04-04):

delegation:
  model: 'Codex-sonnet-4-6'   # was empty (inherited Opus)
  provider: ''                  # inherits parent provider

This stops subagents from burning Opus quota on research/triage work.

Stronger option: Route delegation through Copilot to fully bypass Anthropic OAuth:

delegation:
  model: 'Codex-sonnet-4.6'
  provider: 'copilot'

This routes ALL subagent work through $9/mo Copilot sub instead of $200/mo Codex OAuth. Use if Anthropic starts billing Hermes as "extra usage."

Within a single session, route subagent work to cheapest capable model:

• Research/triage subagents → Sonnet via delegation (NOT Opus)
• Implementation subagents → Codex Opus (only when needed)
• Review subagents → Codex

Gemini limitation: Google/Gemini is NOT a native Hermes provider. Cannot route subagents to Gemini. Use separate terminal sessions (h-gemini) or OpenRouter.

Evidence-Based Routing (Phase-E Audit, 168K calls over 31 days)

Quantified shift opportunity from cross-agent audit:

• ~8,000 Codex read-calls/month → Gemini (research, doc ingestion, standards mapping)
• ~4,000 Codex write-calls/month → Codex (test writing, bounded implementation)
• ~800 Hermes doc-calls/month → Gemini (documentation, literature)
• Gemini reviews (81% approve) → repurpose to research (Codex is the hard gate at 38%)
• Net: Codex drops from 95% → ~65-70% of work

Decision: Don't over-engineer routing automation now. The priority order is:

1. Establish workflows (rolling queue, overnight batch, hard-stops)
2. Observe real patterns over 2-4 weeks — which tasks naturally fit which agent
3. Then formalize routing based on evidence, not theory The current routing matrix is a hypothesis. Let the work prove it. See #1857.

Rolling 1-Week Agent Work Queue (#1857)

Every agent should always have 5+ tasks queued. File: notes/agent-work-queue.md

• Updated every Sunday night
• Overnight pattern: Gemini=Terminal1 (prep), Codex=T2+T5 (impl), Codex=T3+T4 (tests+review)
• Gemini prep tasks explicitly linked to downstream Codex/Codex implementation tasks

Anthropic Third-Party Harness Policy (CRITICAL — Apr 4, 2026)

Anthropic announced that starting Apr 4, 2026, third-party harnesses using Codex subscription OAuth will draw from "extra usage" (costs extra) instead of subscription quota.

Hermes IS affected. It spoofs Codex identity:

• Reads OAuth tokens from ~/.Codex/.credentials.json
• Sends Codex-20250219 beta headers
• Spoofs Codex user-agent version
• Same pattern as OpenClaw (348K stars, users canceling Anthropic subs over this)

Mitigations:

1. Claim the free one-time credit (= $200, must redeem by Apr 17, good 90 days) ✅ CLAIMED Apr 4, 2026 — valid 90 days (~Jul 3)
2. Pre-purchase extra usage bundles at up to 30% off
3. Use --provider copilot as alternative Codex access path (GitHub auth, not Anthropic OAuth)
4. Route subagents to free OSS models instead of Codex
5. Use Codex CLI directly for heavy work (not affected — it's Anthropic's own tool)

Monitor: Check ~/.hermes/logs/errors.log for new error types: extra_usage_required, billing-related 402/403. Check https://console.anthropic.com/settings/billing.

As of Apr 4 12:37pm: Hermes still working on subscription. No extra charges detected yet. But OpenAI Plus (one of two subs) is maxed out until Apr 8.

Proven Batch Execution Pattern (Updated 2026-04-04)

Gemini is most cost-effective when running 5-6 related research tasks per session (~2 min, 26 tool calls, $0 from $20/mo sub).

Session Structure

h-router-gemini -t terminal,file,web -q "$(cat /tmp/gemini-batch-N.txt)"

Task Template (for each batch)

• Group 5-6 related tasks together (e.g., all standards gaps, all research topics)
• Each task produces ONE file + commits + closes an issue
• Give clear file paths, commit messages, and issue close commands
• Set max 420s timeout per session to avoid rate limiting

Proven Batches (2026-04-04)

Overnight Cron Pattern

# 4 batches spaced 75 min apart through the night
# Each runs once, uses gemini-2.5-pro via openrouter provider
- name: gemini-overnight-batch-1
  schedule: 00:30  # starts at midnight
  model: google/gemini-2.5-pro
  provider: openrouter

- name: gemini-overnight-batch-2
  schedule: 01:30  # 60 min later
  model: google/gemini-2.5-pro
  provider: openrouter

Sandbox Isolation Gotcha

Gemini hermes sessions run in isolated sandboxes. Files created during the session are destroyed when it ends EXCEPT:

• Git commits persist (sandbox shares the git repo)
• So: Always commit before session end, don't rely on uncommitted files

Working vs Broken Aliases (as of 2026-04-04)

h-router-gemini  # WORKS: hermes chat --provider openrouter -m google/gemini-2.5-pro
h-gemini         # BROKEN: uses custom base-url that Hermes CLI doesn't support
h-copilot-gemini # WORKS: gemini via Copilot sub (uses Copilot quota, not $20 Gemini)

Key finding: h-router-gemini works perfectly for batch research. Use this one, not h-gemini.

Free/OSS Model Tier (Zero Cost Alternatives)

Hermes supports 18 providers.

Hermes supports 18 providers. Several offer FREE open-source models:

Copilot is the hidden gem: Your $9/mo annual sub gives Hermes access to Codex Opus/Sonnet + Gemini 2.5 Pro + GPT-5.4 through GitHub's auth (separate from Anthropic OAuth).

Copilot aliases (READY — GH_TOKEN configured Apr 4, 2026):

h-copilot='hermes chat --provider copilot -m Codex-sonnet-4.6'
h-copilot-gemini='hermes chat --provider copilot -m gemini-2.5-pro'
h-copilot-gpt='hermes chat --provider copilot -m gpt-5.4'

DeepSeek aliases (WORKING — DEEPSEEK_API_KEY configured, CLI patched):

h-deepseek='hermes chat --provider deepseek -m deepseek-chat'
h-deepseek-reason='hermes chat --provider deepseek -m deepseek-reasoner'

Nous Portal gotcha: :free models are free to RUN, but creating an API key requires a funded account ("out of funds" error at portal.nousresearch.com). Bot detection blocks headless browser signup. Alternative: hermes setup model → Nous → OAuth device flow.

DeepSeek CLI gotcha: deepseek was missing from Hermes CLI --provider argparse choices. Patched in ~/.hermes/hermes-agent/hermes_cli/main.py line ~4041. Hermes updates may overwrite this — re-check after updates.

Local inference NOT viable: dev-primary has GTX 750 Ti (2GB VRAM). Use cloud-hosted OSS instead.

Copilot is the best multi-model hedge: $9/mo sub gives Codex+Gemini+GPT via GitHub auth, independent of Anthropic OAuth billing. GH_TOKEN auto-generated from gh auth token.

Launch Verification Pattern for Codex GPT-5.4

When a session says the config is fixed, do not stop at codex --version or TOML inspection. Verify an actual model invocation.

Use this exact smoke test:

codex exec --skip-git-repo-check --sandbox read-only -m gpt-5.4 \
  'Reply with exactly CODEX_GPT54_OK and nothing else.'

Expected success signals:

• output shows model: gpt-5.4
• a session id is created
• final assistant output is exactly CODEX_GPT54_OK

Observed on 2026-04-09:

• config loaded cleanly from ~/.codex/config.toml
• invocation succeeded
• Codex printed provider: openai in the exec banner even though the subscription workflow is the Codex CLI path

Important CLI gotcha:

• codex auth status is NOT a valid subcommand in codex-cli 0.118.0
• use codex --help, codex login --help, and especially the codex exec ... smoke test above instead of trying status

Error Log Monitoring

Check for billing/auth issues: grep -i '401\|403\|429\|billing\|extra.usage\|rate.limit' ~/.hermes/logs/errors.log

Known error patterns:

• Anthropic 429 "rate limit exceeded" = subscription rate limit (normal, transient)
• OpenAI 429 "usage_limit_reached" plan_type "plus" = sub maxed, check resets_at timestamp
• Anthropic 401 "Invalid authentication credentials" = OAuth token may need refresh, or policy enforcement
• OpenAI 400 model not supported = wrong model for Codex provider (gpt-4.1, o4-mini, gpt-4o don't work via ChatGPT account)

Pitfalls

• GEMINI_API_KEY in ~/.hermes/.env is used only when you explicitly route to Gemini. Do NOT rely on Gemini as cheap/default automatic routing. (scanner-allow:hermes_env_access — doc reference, not an instruction to read secrets)
• Validate ~/.hermes/.env for bad overrides like GEMINI_BASE_URL=h-which. A malformed env base URL can leak into active model state and then into config.yaml. (scanner-allow:hermes_env_access — doc reference, not an instruction to read secrets)
• As of 2026-04-09, Hermes was patched so _model_flow_api_key_provider() ignores invalid existing env base URLs and invalid typed base URL overrides unless they start with http:// or https://.
• After fixing .env, also inspect ~/.hermes/auth.json credential_pool entries for stale provider base_url residue. We observed Gemini still carrying base_url: h-which in auth metadata even after .env was corrected.
• If reviewing quota-hardening work, do not mistake the presence of hermes_cli/codex_quota.py for a complete solution. The critical check is whether update_codex_credential_usage(...) is actually called from live runtime paths. If it is not wired, /quota and startup warnings are mostly structural/stale.
• When reviewing provider health summaries, verify they reuse the real provider credential resolution paths. A simple env-var check can miss live configs (example observed: Copilot health checking only GITHUB_TOKEN while the actual machine used GH_TOKEN).
• OpenRouter key needs credits loaded to run paid models (Gemini, GPT, Codex via OR). Free-tier models like qwen/qwen3.6-plus:free work with zero balance.
• h-gemini uses Google AI Studio endpoint directly (not OpenRouter credits) — explicit use only under the Gemini subscription.
• smart_model_routing should remain disabled on this setup. Re-enabling it with Gemini/Copilot cheap routes reintroduces the exact quota/fallback failure mode that was cleaned up.
• Don't forget source ~/.bash_aliases in new terminals for aliases to take effect
• hermes model / command-window provider selection can prompt for Base URL [...]. If a nonsense token appears there, leave it blank; Hermes now ignores invalid values, but the safest operator habit is still blank unless you intend an advanced override.
• If you see a 128k context message for Codex, treat it as likely generic metadata fallback, not proof of the real Codex endpoint limit.
• deepseek provider was missing from CLI argparse choices — patched in main.py; may need re-patching after Hermes updates
• Running --provider nous without -m sends the default model (e.g. gpt-5.4) to Nous gateway, burning Nous credits — always specify both provider AND model
• hermes --h-deepseek does NOT work — aliases are shell commands, type h-deepseek directly (no hermes prefix)
• The routing-config.yaml is a specification, not a live router — no script dispatches tasks from it
• cost-tracking.jsonl is the richest data source but Codex-only; you have zero visibility into Codex/Gemini spend
• agent-usage-optimizer sub-skills are all archived — the skill is effectively documentation-only
• Anthropic may start billing Hermes as "extra usage" — monitor errors.log for new error types
• OpenAI Codex provider only supports the gpt-5.x line: gpt-5.5 (live default as of 2026-06), gpt-5.4, gpt-5.4-mini, gpt-5.3-codex, gpt-5.2 — older models (gpt-4.1, o4-mini, gpt-4o) are no longer available via ChatGPT account
• GitHub Copilot provider accesses Codex/Gemini/GPT through GitHub auth — different auth path from direct Anthropic OAuth, useful as a hedge
• Nous Portal login has aggressive bot detection — cannot sign up or get API keys via headless browser; must use regular browser at https://portal.nousresearch.com/
• Stale Codex exhaustion state persists across three layers after weekly reset: auth.json error fields, ~/.cache/agent-quota.json synthetic entries, and codex_quota.py state. As of 2026-04-10, codex_quota.py was patched with: (1) last_error_reset_at recovery check, (2) last_error_message-based detection, (3) 12h staleness expiry for exhausted_* cache entries. If false warnings recur, clear all three layers — see #2107.
• To manually clear stale Codex exhaustion: python3 -c "import json,time; [code to clear auth.json and agent-quota.json]" — or use hermes auth reset openai-codex followed by query-quota.sh --refresh.
• Related GitHub issues: #1838 (credit governance), #1839 (workflow hard-stops), #1855 (utilization tracker), #1856 (model switching), #1857 (rolling agent queue), #2107 (auto-clear stale exhaustion), #2108 (quota cache cron scrubber), #2109 (test coverage for recovery logic)