fix(models): use Anthropic-native headers for model validation by H-Ali13381 · Pull Request #12618 · NousResearch/hermes-agent

H-Ali13381 · 2026-04-19T16:38:27Z

Problem

When switching models with the Anthropic provider, /model <name> always fails with a misleading "service unreachable" error — even with a valid API key.

Root cause: validate_requested_model() falls through to a generic OpenAI-compatible /v1/models probe that sends Authorization: Bearer <key>. Anthropic's API requires x-api-key + anthropic-version headers (or Authorization: Bearer only for OAuth tokens from Claude Code), so every probe returns 401 Unauthorized, which the validation code interprets as the service being down.

Fix

Add a dedicated normalized == "anthropic" early-return branch that calls the existing _fetch_anthropic_models() helper, which already handles both regular API keys and Claude Code OAuth tokens correctly. This mirrors the existing pattern for openai-codex, copilot, and bedrock.

The branch also adds:

Fuzzy auto-correct (cutoff 0.9) — catches near-exact typos (e.g. claude-sonnet-4 → claude-sonnet-4-5)
Fuzzy suggestions (cutoff 0.5) — surfaces similar model IDs when the requested one is not listed
Graceful fallback — if the token cannot be resolved or the network is down, accepts with a warning rather than hard-failing, since newer/preview/snapshot model IDs are sometimes not listed on /v1/models yet

How to reproduce (before fix)

# With ANTHROPIC_API_KEY set to a valid key:
/model claude-sonnet-4-6 --provider anthropic
# → "Anthropic service unreachable" (every probe 401s with wrong headers)

After fix

/model claude-sonnet-4-6 --provider anthropic
# → Validates correctly via x-api-key + anthropic-version headers
# → Auto-corrects typos, suggests similar model IDs on mismatch
# → Falls through gracefully if network is unavailable

Files changed

hermes_cli/models.py — 43-line insertion; no other files touched

The generic /v1/models probe in validate_requested_model() sent a plain 'Authorization: Bearer <key>' header, which works for OpenAI-compatible endpoints but results in a 401 Unauthorized from Anthropic's API. Anthropic requires x-api-key + anthropic-version headers (or Bearer for OAuth tokens from Claude Code). Add a provider-specific branch for normalized == 'anthropic' that calls the existing _fetch_anthropic_models() helper, which already handles both regular API keys and Claude Code OAuth tokens correctly. This mirrors the pattern already used for openai-codex, copilot, and bedrock. The branch also includes: - fuzzy auto-correct (cutoff 0.9) for near-exact model ID typos - fuzzy suggestions (cutoff 0.5) when the model is not listed - graceful fall-through when the token cannot be resolved or the network is unreachable (accepts with a warning rather than hard-fail) - a note that newer/preview/snapshot model IDs can be gate-listed and may still work even if not returned by /v1/models Fixes Anthropic provider users seeing 'service unreachable' errors when running /model <claude-model> because every probe 401'd.

alt-glitch · 2026-04-23T06:47:45Z

Competes with #13189 and #12950 — all three fix Anthropic model validation using wrong auth headers. Review needed to pick one.

@briandevans

Salvage of the Gemini-specific piece from PR #12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of #12585 was subsumed by #12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

teknium1 · 2026-04-27T04:41:39Z

Thanks for this fix, @H-Ali13381! The change has already landed on main — this was an automated hermes-sweeper review.

Evidence:

Commit 2303dd8 on main implements the exact fix from this PR: the normalized == "anthropic" branch in validate_requested_model() dispatching to _fetch_anthropic_models() with x-api-key + anthropic-version headers, fuzzy auto-correct (cutoff 0.9), fuzzy suggestions (cutoff 0.5), and graceful fallback.
The implementation lives at hermes_cli/models.py lines 2733–2785.
The fix landed after the v2026.4.23 release tag and will ship in the next weekly release.

Closing as implemented on main.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

@briandevans

…2532) Salvage of the Gemini-specific piece from PR NousResearch#12585 by @briandevans. Gemini's OpenAI-compat /v1beta/openai/models endpoint returns IDs prefixed with 'models/' (native Gemini-API convention), so set-membership against curated bare IDs drops every model. Strip the prefix before comparison. The Anthropic static-catalog piece of NousResearch#12585 was subsumed by NousResearch#12618's _fetch_anthropic_models() branch landing earlier in the same salvage PR. Full branch cherry-pick was skipped because it also carried unrelated catalog-version regressions.

H-Ali13381 and others added 2 commits April 19, 2026 12:34

Merge branch 'main' into fix/anthropic-model-validation-auth

0903cb8

alt-glitch mentioned this pull request Apr 22, 2026

fix(models): use x-api-key for Anthropic API probing #13189

Closed

3 tasks

alt-glitch added type/bug Something isn't working P1 High — major feature broken, no workaround comp/cli CLI entry point, hermes_cli/, setup wizard provider/anthropic Anthropic native Messages API labels Apr 23, 2026

teknium1 mentioned this pull request Apr 24, 2026

fix(models): consolidated validation + picker — anthropic_messages, native Anthropic, Gemini prefix, OpenAI catalog #15136

Merged

teknium1 mentioned this pull request Apr 24, 2026

fix(models): accept Gemini + Anthropic in gateway /model picker (#12532) #12585

Closed

teknium1 closed this Apr 27, 2026

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fix(models): use Anthropic-native headers for model validation#12618

fix(models): use Anthropic-native headers for model validation#12618
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H-Ali13381:fix/anthropic-model-validation-auth

H-Ali13381 commented Apr 19, 2026

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H-Ali13381 commented Apr 19, 2026

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alt-glitch commented Apr 23, 2026

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