Description

Migrates both the Python and TypeScript Ollama embedders from the deprecated ollama.embeddings() API to the current ollama.embed() API. The old endpoint (/api/embeddings) uses prompt: and
returns response.embedding, while the new endpoint (/api/embed) uses input: and returns response.embeddings[0]. This breaks for anyone running Ollama server 0.17+.

Also fixes a sneaky bug where ensureModelExists() would trigger a redundant model pull on every startup because "nomic-embed-text" never matched "nomic-embed-text:latest" from ollama list
due to strict string equality.

Fixes #4155

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Unit Test

Python (4 tests passed):

• test_embed_text — verifies client.embed() called with model= and input=, returns embeddings[0]
• test_ensure_model_exists — verifies pull is triggered when model is missing
• test_ensure_model_exists_normalizes_latest_tag — verifies nomic-embed-text matches nomic-embed-text:latest
• test_embed_empty_response_raises — verifies ValueError on empty embeddings

TypeScript (7 tests passed):

• embed() happy path with model and input
• embed() non-string input coercion
• embedBatch() multiple inputs
• ensureModelExists() skips pull when model present
• ensureModelExists() pulls when model missing
• ensureModelExists() normalizes :latest tag
• embed() throws on empty embeddings response

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Maintainer Checklist

• closes Ollama embedder uses deprecated embeddings() API — should use embed() with input: field #4155
• Made sure Checks passed