### What problem does this PR solve?

Python class Document was missing "meta_fields", e.g. when querying, the
document instances came without meta_fields

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

- The default dataset_ids "kb1" was removed from the Chat class. 
- The HTTP API response does not include the dataset_ids field.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

- Update version tags in README files (including translations) from
v0.20.0 to v0.20.1
- Modify Docker image references and documentation to reflect new
version
- Update version badges and image descriptions
- Maintain consistency across all language variants of README files

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

list_document supports range filtering.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

- Update version tags in README files (including translations) from
v0.19.1 to v0.20.0
- Modify Docker image references and documentation to reflect new
version
- Update version badges and image descriptions
- Maintain consistency across all language variants of README files

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

Added infinity rank_feature support

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Close #8943

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Fix typo process_duration.

### Type of change

- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?

This PR adds fields to the `Chunk` class to store retrieval results like
similarity scores, term similarity, vector similarity, positions, and
document type. This allows the chunk object to hold all the information
needed when returning search results from the vector database.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Previous:
- Defaulted to hardcoded model 'BAAI/bge-large-zh-v1.5@BAAI'
- Did not respect user-configured default embedding_model

Now:
- Correctly prioritizes user-configured default embedding_model

Other:
- Make embedding_model optional in CreateDatasetReq with proper None
handling
- Add default embedding model fallback in dataset update when empty
- Enhance validation utils to handle None values and string
normalization
- Update SDK default embedding model to None to match API changes
- Adjust related test cases to reflect new validation rules

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

- Update Docker image version badges and references from v0.19.0 to
v0.19.1
- Modify version mentions in all localized README files (id, ja, ko,
pt_br, tzh, zh)
- Update version in docker/README.md and related documentation files
- Includes updates to Helm values and Python SDK dependencies

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

1. rename var
2. update if statement

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

### What problem does this PR solve?

Refactoring codes for SDK

### Type of change

- [x] Refactoring

### What problem does this PR solve?

- Remove pagerank from CreateDatasetReq and add to UpdateDatasetReq
- Add pagerank update logic in dataset update endpoint
- Update API documentation to reflect changes
- Modify related test cases and SDK references

#8208

This change makes pagerank a mutable property that can only be set after
dataset creation, and only when using elasticsearch as the doc engine.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Previously when LLM.model_name was not configured:
- System incorrectly defaulted to 'deepseek-chat' model
- This caused permission errors for unauthorized tenants

Now:
- Use tenant's default chat_model configuration first

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Previously when LLM.rerank_model was not configured:
- SDK would pass None as the value
- Database field with null=False constraint would reject it
- Caused storage failures for unset rerank_model cases

Now:
- SDK checks for None value before database operations
- Provides empty string as default when rerank_model is unset

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Add sdk document test cases

### Type of change

- [x] Add test cases

### What problem does this PR solve?

Added name filtering capability for Dataset.list_documents()

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

An exception is thrown only when the json file has only two keys, `code`
and `message`. In other cases, response.content is returned normally.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

#8067 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

- Removed hardcoded Zhipu API key from codebase
- New requirement: Tests now require ZHIPU_AI_API_KEY environment
variable
  Example: export ZHIPU_AI_API_KEY=your_api_key_here

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

The Unicode codepoint '，' (U+FF0C) is meant to be used in Chinese text,
but this is English text. It looks like a comma followed by a space, but
isn't. Of course I didn't change actual Chinese text.

### What problem does this PR solve?

Mixup of Unicode characters. This is probably unnoticed by most users,
but I wonder if screen readers would read it out differently or if LLMs
would trip up on it.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):

### What problem does this PR solve?

#8057 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Fix parser_config=None handling in create_dataset

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Change filename length limit from 128 to 256

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

### What problem does this PR solve?

This PR solve the problems metioned in the
pr(https://github.com/infiniflow/ragflow/pull/7140) which is also
submitted by me

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):


### Introduction
I fixed the problems when using OpenSearch as the DOC_ENGINE, the
failures of pytest and the wrong API's return.
Mainly about delete chunk, list chunks, update chunk, retrieval chunk.
The pytest comand "cd sdk/python && uv sync --python 3.10 --group test
--frozen && source .venv/bin/activate && cd test/test_http_api &&
DOC_ENGINE=opensearch pytest test_chunk_management_within_dataset -s
--tb=short " is finally successful.

###Others
As some changes between Elasticsearch And Opensearch differ, some pytest
results about OpenSearch are correct and resonable. However, some pytest
params (skipif params) are incompatible. So I changed some pytest params
about skipif.

As a search engine programmer, I will still focus on the usage of vector
databases (especially OpenSearch) for the RAG stuff.
Thanks for your review

### What problem does this PR solve?

update for v0.19.0

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

change default models to buildin models
https://github.com/infiniflow/ragflow/issues/7774

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

This PR introduces Pydantic-based validation for the list datasets HTTP
API, improving code clarity and robustness. Key changes include:

Pydantic Validation
Error Handling
Test Updates
Documentation Updates

### Type of change

- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?

change variable for ZHIPU_AI_API_KEY

### Type of change

- [x] Update test case

### What problem does this PR solve?

use environment variable for ZHIPU_AI_API_KEY

### Type of change

- [x] Test update

### What problem does this PR solve?

This PR introduces Pydantic-based validation for the delete dataset HTTP
API, improving code clarity and robustness. Key changes include:

1. Pydantic Validation
2. Error Handling
3. Test Updates
4. Documentation Updates

### Type of change

- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?

Fix  HTTP API Create/Update dataset parser config default value error

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Hello, we are using ragflow as a backend service, so we need to manage
agents from our own frontend. So adding these http APIs to manage
agents.

The code logic is copied and modified from the `rm` and `save` methods
in `api/apps/canvas_app.py`.

btw, I found that the `save` method in `canvas_app.py` actually allows
to modify an agent to an existing title, so I kept the behavior in the
http api. I'm not sure if this is intentional.

### Type of change

- [ ] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):

### What problem does this PR solve?


Close #7567

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Skip unstable test cases to ensure daily testing stability

### Type of change

- [x] Update test cases

### What problem does this PR solve?

This PR introduces Pydantic-based validation for the update dataset HTTP
API, improving code clarity and robustness. Key changes include:
1. Pydantic Validation
2. ​​Error Handling
3. Test Updates
4. Documentation Updates
5. fix bug: #5915

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?

Configure test case priorities to reduce CI execution time

### Type of change

- [x] Test cases update

### What problem does this PR solve?

Optimize dataset validation and add function docs

### Type of change

- [x] Refactoring

### What problem does this PR solve?

change create dataset delimiter default value to r'\n'

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Remove unnecessary parameter restrictions in dataset creation API

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Deprecate get_dataset_id_and_document_id fixture, use add_document
instead

### Type of change

- [x] Update test cases

### What problem does this PR solve?

This PR introduces Pydantic-based validation for the create dataset HTTP
API, improving code clarity and robustness. Key changes include:
1. Pydantic Validation
2. ​​Error Handling
3. Test Updates
4. Documentation

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?


### Type of change

- [x] Refactoring

### What problem does this PR solve?

Enhance capability of `list_docs`.

Breaking change: change method from `GET` to `POST`.

### Type of change

- [x] Refactoring
- [x] Enhancement with breaking change

### What problem does this PR solve?

The knowledge_graph chunk method is deprecated and should no longer be
used. #7184.

### Type of change

- [x] Refactoring

### What problem does this PR solve?

update for v0.18.0

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

Enhance capability of `list_kbs`.

Breaking change: change method from `GET` to `POST`.

### Type of change

- [x] Refactoring
- [x] Enhancement with breaking change

### What problem does this PR solve?

Fix retrieval testing wrong pagination. #7171 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

### What problem does this PR solve?

cover [Delete chat assistant's
sessions](https://ragflow.io/docs/dev/http_api_reference#delete-chat-assistants-sessions)
endpoints

### Type of change

- [x] Add test cases